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Tantillo DJ. Quantum Chemical Interrogation of Reactions Promoted by Dirhodium Tetracarboxylate Catalysts─Mechanism, Selectivity, and Nonstatistical Dynamic Effects. Acc Chem Res 2024. [PMID: 38920276 DOI: 10.1021/acs.accounts.4c00214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
ConspectusRh2L4 catalysts have risen in popularity in the world of organic synthesis, being used to accomplish a variety of reactions, including C-H insertion and cyclopropanation, and often doing so with high levels of stereocontrol. While the mechanisms and origins of selectivity for such reactions have been examined with computational quantum chemistry for decades, only recently have detailed pictures of the dynamic behavior of reacting Rh2L4-complexed molecules become accessible. Our computational studies on Rh2L4 catalyzed reactions are described here, with a focus on C-H insertion reactions of Rh2L4-carbenes. Several issues complicate the modeling of these reactions, each providing an opportunity for greater understanding and each revealing issues that should be incorporated into future rational design efforts. First, the fundamental mechanism of C-H insertion is discussed. While early quantum chemical studies pointed to transition structures with 3-center [C-H-C] substructures and asynchronous hydride transfer/C-C bond formation, recent examples of reactions with particularly flat potential energy surfaces and even discrete zwitterionic intermediates have been found. These reactions are associated with systems bearing π-donating groups at the site of hydride transfer, allowing for an intermediate with a carbocation substructure at that site to be selectively stabilized. Second, the possible importance of solvent coordination at the Rh atom distal to the carbene is discussed. While effects on reactivity and selectivity were found to be small, they turn out not to be negligible in some cases. Third, it is shown that, in contrast to many other transition metal promoted reactions, many Rh2L4 catalyzed reactions likely involve dissociation of the Rh2L4 catalyst before key chemical steps leading to products. When to expect dissociation is associated with specific features of substrates and the product-forming reactions in question. Often, dissociation precedes transition structures for pericyclic reactions that involve electrons that would otherwise bind to Rh2L4. Finally, the importance of nonstatistical dynamic effects, characterized through ab initio molecular dynamics studies, in some Rh2L4 catalyzed reactions is discussed. These are reactions where transition structures are shown to be followed by flat regions, very shallow minima, and/or pathways that bifurcate, all allowing for trajectories from a single transition state to form multiple different products. The likelihood of encountering such a situation is shown to be associated again with the likelihood of formation of zwitterionic structures along reaction paths, but ones for which pathways to multiple products are expected to be associated with very low or no barriers. The connection between these features and reduced yields of desired products are highlighted, as are the means by which some Rh2L4 catalysts modulate dynamic behavior to produce particular products in high yield.
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Affiliation(s)
- Dean J Tantillo
- Department of Chemistry, University of California─Davis, 1 Shields Avenue, Davis, California 95616, United States
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2
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Wheeler JI, Schaefer AJ, Ess DH. Trajectory-Based Time-Resolved Mechanism for Benzene Reductive Elimination from Cyclopentadienyl Mo/W Phenyl Hydride Complexes. J Phys Chem A 2024; 128:4775-4786. [PMID: 38836889 DOI: 10.1021/acs.jpca.4c01788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Calculated potential energy structures and landscapes are very often used to define the sequence of reaction steps in an organometallic reaction mechanism and interpret kinetic isotope effect (KIE) measurements. Underlying most of this structure-to-mechanism translation is the use of statistical rate theories without consideration of atomic/molecular motion. Here we report direct dynamics simulations for an organometallic benzene reductive elimination reaction, where nonstatistical intermediates and dynamic-controlled pathways were identified. Specifically, we report single spin state as well as mixed spin state quasiclassical direct dynamics trajectories in the gas phase and explicit solvent for benzene reductive elimination from Mo and W bridged cyclopentadienyl phenyl hydride complexes ([Me2Si(C5Me4)2]M(H)(Ph), M = Mo and W). Different from the energy landscape mechanistic sequence, the dynamics trajectories revealed that after the benzene C-H bond forming transition state (often called reductive coupling), σ-coordination and π-coordination intermediates are either skipped or circumvented and that there is a direct pathway to forming a spin flipped solvent caged intermediate, which occurs in just a few hundred femtoseconds. Classical molecular dynamics simulations were then used to estimate the lifetime of the caged intermediate, which is between 200 and 400 picoseconds. This indicates that when the η2-π-coordination intermediate is formed, it occurs only after the first formation of the solvent-caged intermediate. This dynamic mechanism intriguingly suggests the possibility that the solvent-caged intermediate rather than a coordination intermediate is responsible (or partially responsible) for the inverse KIE value experimentally measured for W. Additionally, this dynamic mechanism prompted us to calculate the kH/kD KIE value for the C-H bonding forming transition states of Mo and W. Surprisingly, Mo gave a normal value, while W gave an inverse value, albeit small, due to a much later transition state position.
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Affiliation(s)
- Joshua I Wheeler
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84604, United States
| | - Anthony J Schaefer
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84604, United States
| | - Daniel H Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84604, United States
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3
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Schaefer AJ, Ess DH. Vibrational synchronization and its reaction pathway influence from an entropic intermediate in a dirhodium catalyzed allylic C-H activation/Cope rearrangement reaction. Phys Chem Chem Phys 2024; 26:11386-11394. [PMID: 38586933 DOI: 10.1039/d4cp00657g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
In reactions with consecutive transition states without an intermediate, and an energy surface bifurcation, atomic motion generally determines product selectivity. Understanding this dynamic-based selectivity can be straightforward if there is extremely fast descent from the first transition state to a product. However, in cases where a nonstatistical roaming/entropic intermediate occurs prior to product formation the motion that influences selectivity can be difficult to identify. Here we report quasiclassical direct dynamics trajectories for the dirhodium catalyzed reaction between styryldiazoacetate and 1,4-cyclohexadiene and prior experiments by Davies showed competitive allylic C-H insertion and Cope products. Trajectories confirmed the proposed energy surface bifurcation and revealed that dirhodium vinylcarbenoid when reacting with 1,4-cyclohexadiene can induce either a dynamically concerted pathway or a dynamically stepwise pathway with a nonstatistical entropic tight ion-pair intermediate. In the dynamically stepwise reaction pathway C-H insertion versus Cope selectivity is highly influenced by whether or not vibrational synchronization occurs in the nonstatistical entropic intermediate. This vibrational synchronization highlights the possible need for an entropic intermediate to have organized transition state-like motion to proceed to a product.
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Affiliation(s)
- Anthony J Schaefer
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84604, USA.
| | - Daniel H Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84604, USA.
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4
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Ito T, Maeda S, Harabuchi Y. Exploring Downhill Bifurcations in [3,3]-Sigmatropic Rearrangement by Finding Transitions from an Uphill Bifurcation to a Downhill Bifurcation. J Chem Theory Comput 2024; 20:2049-2057. [PMID: 38316126 DOI: 10.1021/acs.jctc.3c01383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
Downhill bifurcation is a phenomenon in which an ensemble of trajectories passing through a transition state (TS), called an ambimodal TS, bifurcates into multiple products. Finding downhill bifurcations for unreported pairs of chemical transformations is essential, because they affect reaction selectivity. Marx et al. reported that perturbations such as applying mechanical stress or changing a substituent cause a transition from an uphill bifurcation to a downhill bifurcation in the ring-opening reaction of cyclopropane derivatives (ChemPhysChem, 2018, 19, 837-847). Investigating the occurrence of this phenomenon in other reactions, especially in pericyclic reactions, is interesting for understanding and controlling the reaction selectivity considering downhill bifurcations. In this study, we proposed a method for finding perturbation-induced downhill bifurcations and applied it to three pericyclic reactions. The transition from an uphill bifurcation to a downhill bifurcation occurred in two of the three pericyclic reactions, one of which was previously unreported. Interestingly, the occurrence of a downhill bifurcation by a perturbation depended on the directions of the intrinsic reaction coordinate paths of the two TSs when they emerged from the reactant minimum. Our method can be applied in mechanistic studies to avoid the risk of overlooking downhill bifurcations.
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Affiliation(s)
- Takuma Ito
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
- Japan Science and Technology Agency (JST), Exploratory Research for Advanced Technology (ERATO), Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Sapporo 060-0810, Japan
| | - Yu Harabuchi
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan
- Japan Science and Technology Agency (JST), Exploratory Research for Advanced Technology (ERATO), Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Sapporo 060-0810, Japan
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5
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Pu M, Nielsen CDT, Senol E, Sperger T, Schoenebeck F. Post-Transition-State Dynamic Effects in the Transmetalation of Pd(II)-F to Pd(II)-CF 3. JACS AU 2024; 4:263-275. [PMID: 38274253 PMCID: PMC10806791 DOI: 10.1021/jacsau.3c00724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/27/2024]
Abstract
The observation of post-transition-state dynamic effects in the context of metal-based transformation is rare. To date, there has been no reported case of a dynamic effect for the widely employed class of palladium-mediated coupling reactions. We performed an experimental and computational study of the trifluoromethylation of Pd(II)F, which is a key step in the Pd(0)/Pd(II)-catalyzed trifluoromethylation of aryl halides or acid fluorides. Our experiments show that the cis/trans speciation of the formed Pd(II)CF3 is highly solvent- and transmetalation reagent-dependent. We employed GFN2-xTB- and B3LYP-D3-based molecular dynamics trajectory calculations (with and without explicit solvation) along with high-level QM calculations and found that depending on the medium, different transmetalation mechanisms appear to be operative. A statistically representative number of Born-Oppenheimer molecular dynamics (MD) simulations suggest that in benzene, a difluorocarbene is generated in the transmetalation with R3SiCF3, which subsequently recombines with the Pd via two distinct pathways, leading to either the cis- or trans-Pd(II)CF3. Conversely, GFN2-xTB simulations in MeCN suggest that in polar/coordinating solvents an ion-pair mechanism is dominant. A CF3 anion is initially liberated and then rebinds with the Pd(II) cation to give a cis- or trans-Pd(II). In both scenarios, a single transmetalation transition state gives rise to both cis- and trans-species directly, owing to bifurcation after the transition state. The potential subsequent cis- to trans isomerization of the Pd(II)CF3 was also studied and found to be strongly inhibited by free phosphine, which in turn was experimentally identified to be liberated through displacement by a polar/coordinating solvent from the cis-Pd(II)CF3 complex. The simulations also revealed how the variation of the Pd-coordination sphere results in divergent product selectivities.
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Affiliation(s)
- Maoping Pu
- Institute of Organic Chemistry,
RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | | | - Erdem Senol
- Institute of Organic Chemistry,
RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Theresa Sperger
- Institute of Organic Chemistry,
RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Franziska Schoenebeck
- Institute of Organic Chemistry,
RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
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6
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Whitehead J, Leferink NGH, Johannissen LO, Hay S, Scrutton NS. Decoding Catalysis by Terpene Synthases. ACS Catal 2023; 13:12774-12802. [PMID: 37822860 PMCID: PMC10563020 DOI: 10.1021/acscatal.3c03047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/31/2023] [Indexed: 10/13/2023]
Abstract
The review by Christianson, published in 2017 on the twentieth anniversary of the emergence of the field, summarizes the foundational discoveries and key advances in terpene synthase/cyclase (TS) biocatalysis (Christianson, D. W. Chem Rev2017, 117 (17), 11570-11648. DOI: 10.1021/acs.chemrev.7b00287). Here, we review the TS literature published since then, bringing the field up to date and looking forward to what could be the near future of TS rational design. Many revealing discoveries have been made in recent years, building on the knowledge and fundamental principles uncovered during those initial two decades of study. We use these to explore TS reaction chemistry and see how a combined experimental and computational approach helps to decipher the complexities of TS catalysis. Revealed are a suite of catalytic motifs which control product outcome in TSs, some obvious, some more subtle. We examine each in detail, using the most recent papers and insights to illustrate how exactly this fascinating class of enzymes takes a single acyclic substrate and turns it into the many thousands of complex terpenoids found in Nature. We then explore some of the recent strategies for TS engineering, including machine learning and other data-driven approaches. From this, rational and predictive engineering of TSs, "designer terpene synthases", will begin to emerge as a realistic goal.
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Affiliation(s)
- Joshua
N. Whitehead
- Manchester
Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, United Kingdom
| | - Nicole G. H. Leferink
- Future
Biomanufacturing Research Hub (FBRH), Manchester Institute of Biotechnology,
Department of Chemistry, The University
of Manchester, Manchester, M1 7DN, United
Kingdom
| | - Linus O. Johannissen
- Manchester
Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, United Kingdom
| | - Sam Hay
- Manchester
Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, United Kingdom
| | - Nigel S. Scrutton
- Manchester
Institute of Biotechnology, Department of Chemistry, The University of Manchester, Manchester, M1 7DN, United Kingdom
- Future
Biomanufacturing Research Hub (FBRH), Manchester Institute of Biotechnology,
Department of Chemistry, The University
of Manchester, Manchester, M1 7DN, United
Kingdom
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7
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Sengupta A, Houk KN. Origins of Periselectivity and Regioselectivity in Ambimodal Tripericyclic [8+6]/[6+4]/[4+2] Intramolecular Cycloadditions of a Heptafulvenyl-Fulvene. J Phys Chem A 2023; 127:7976-7983. [PMID: 37713722 DOI: 10.1021/acs.jpca.3c05656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/17/2023]
Abstract
Quantum mechanical calculations and molecular dynamics simulations have elucidated the reaction mechanism for intramolecular cycloadditions of a heptafulvenyl-fulvene tethered by a trimethylene chain. Prior experiments by Liu and Houk reported the formation of only an endo-[8+6] cycloadduct at 185 °C. Liu et al. later reported an exo-[4+2] Diels-Alder cycloadduct as the major product at 140 °C (Tetrahedron, 1999, 55, 9171). Cycloadditions involve Diels-Alder and an ambimodal intramolecular tripericyclic [8+6]/[6+4]/[4+2] cycloaddition. The mechanistic details explain the experimental reports of temperature dependence on the periselectivity of intramolecular cycloadditions. Additional calculations with multireference-based methods CASSCF and NEVPT2 highlight the artifacts of DFT methods and single-reference wavefunction-based CCSD(T) in the description of complete potential energy surface involving various cycloadditions of the heptafulvenyl-fulvene.
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Affiliation(s)
- Arkajyoti Sengupta
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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8
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Yamashita T, Miyamura N, Kawai S. Classification of the HCN isomerization reaction dynamics in Ar buffer gas via machine learning. J Chem Phys 2023; 159:124116. [PMID: 38127399 DOI: 10.1063/5.0156313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 09/07/2023] [Indexed: 12/23/2023] Open
Abstract
The effect of the presence of Ar on the isomerization reaction HCN ⇄ CNH is investigated via machine learning. After the potential energy surface function is developed based on the CCSD(T)/aug-cc-pVQZ level ab initio calculations, classical trajectory simulations are performed. Subsequently, with the aim of extracting insights into the reaction dynamics, the obtained reactivity, that is, whether the reaction occurs or not under a given initial condition, is learned as a function of the initial positions and momenta of all the atoms in the system. The prediction accuracy of the trained model is greater than 95%, indicating that machine learning captures the features of the phase space that affect reactivity. Machine learning models are shown to successfully reproduce reactivity boundaries without any prior knowledge of classical reaction dynamics theory. Subsequent analyses reveal that the Ar atom affects the reaction by displacing the effective saddle point. When the Ar atom is positioned close to the N atom (resp. the C atom), the saddle point shifts to the CNH (HCN) region, which disfavors the forward (backward) reaction. The results imply that analyses aided by machine learning are promising tools for enhancing the understanding of reaction dynamics.
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Affiliation(s)
- Takefumi Yamashita
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
- Department of Physical Chemistry, School of Pharmacy and Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan
| | - Naoaki Miyamura
- Laboratory for Systems Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Shinnosuke Kawai
- Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka 422-8529, Japan
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9
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Ge F, Zhang L, Hou YF, Chen Y, Ullah A, Dral PO. Four-Dimensional-Spacetime Atomistic Artificial Intelligence Models. J Phys Chem Lett 2023; 14:7732-7743. [PMID: 37606602 DOI: 10.1021/acs.jpclett.3c01592] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2023]
Abstract
We demonstrate that AI can learn atomistic systems in the four-dimensional (4D) spacetime. For this, we introduce the 4D-spacetime GICnet model, which for the given initial conditions (nuclear positions and velocities at time zero) can predict nuclear positions and velocities as a continuous function of time up to the distant future. Such models of molecules can be unrolled in the time dimension to yield long-time high-resolution molecular dynamics trajectories with high efficiency and accuracy. 4D-spacetime models can make predictions for different times in any order and do not need a stepwise evaluation of forces and integration of the equations of motions at discretized time steps, which is a major advance over traditional, cost-inefficient molecular dynamics. These models can be used to speed up dynamics, simulate vibrational spectra, and obtain deeper insight into nuclear motions, as we demonstrate for a series of organic molecules.
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Affiliation(s)
- Fuchun Ge
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian 361005, China
| | - Lina Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian 361005, China
| | - Yi-Fan Hou
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian 361005, China
| | - Yuxinxin Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian 361005, China
| | - Arif Ullah
- School of Physics and Optoelectronic Engineering, Anhui University, Hefei 230601, China
| | - Pavlo O Dral
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, Xiamen, Fujian 361005, China
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10
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Martin-Somer A, Xue XS, Jamieson CS, Zou Y, Houk K. Computational Design of a Tetrapericyclic Cycloaddition and the Nature of Potential Energy Surfaces with Multiple Bifurcations. J Am Chem Soc 2023; 145:4221-4230. [PMID: 36757329 PMCID: PMC9951208 DOI: 10.1021/jacs.2c12871] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Indexed: 02/10/2023]
Abstract
An ambimodal transition state (TS) that leads to formation of four different pericyclic reaction products ([4 + 6]-, [2 + 8]-, [8 + 2]-, and [6 + 4]-cycloadducts) without any intervening minima has been designed and explored with DFT computations and quasiclassical molecular dynamics. Direct dynamics simulations propagated from the ambimodal TS show the evolution of trajectories to give the four cycloadducts. The topography of the PES is a key factor in product selectivity. A good correlation is observed between geometrical resemblance of the products to the ambimodal TS (measured by the RMSD) and the ratio of products formed in the dynamics simulations.
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Affiliation(s)
- Ana Martin-Somer
- Departamento
de Química Física Aplicada, Facultad de Ciencias, Módulo
13, Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC Cantoblanco, 28049 Madrid, Spain
| | - Xiao-Song Xue
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, Los Angeles, California 90095, United States
| | - Cooper S. Jamieson
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, Los Angeles, California 90095, United States
| | - Yike Zou
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, Los Angeles, California 90095, United States
| | - K.N. Houk
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, Los Angeles, California 90095, United States
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11
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Tao Z, Qiu T, Subotnik JE. Symmetric Post-Transition State Bifurcation Reactions with Berry Pseudomagnetic Fields. J Phys Chem Lett 2023; 14:770-778. [PMID: 36652556 DOI: 10.1021/acs.jpclett.2c02668] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
We investigate how the Berry force (i.e., the pseudomagnetic force operating on nuclei as induced by electronic degeneracy and spin-orbit coupling (SOC)) might modify a post-transition state bifurcation (PTSB) reaction path and affect product selectivity for situations when multiple products share the same transition state. To estimate the magnitude of this effect, Langevin dynamics are performed on a model system with a valley-ridge inflection (VRI) point in the presence of a magnetic field (that mimics the Berry curvature). We also develop an analytic model for such selectivity that depends on key parameters such as the surface topology, the magnitude of the Berry force, and the nuclear friction. Within this dynamical model, static electronic structure calculations (at the level of generalized Hartree-Fock with spin-orbit coupling (GHF+SOC) theory) suggest that electronic spin induced Berry force effects may indeed lead to noticeable changes in methoxy radical isomerization.
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Affiliation(s)
- Zhen Tao
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Tian Qiu
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Joseph E Subotnik
- Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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12
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de Oliveira MT, Alves JMA, Vrech NL, Braga AAC, Barboza CA. A comprehensive benchmark investigation of quantum chemical methods for carbocations. Phys Chem Chem Phys 2023; 25:1903-1922. [PMID: 36541431 DOI: 10.1039/d2cp04603b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The application of various density functional approximations (DFAs) and an emphasis on popular methods without any consensus have prevailed in computational studies dedicated to carbocations. More importantly, an extensive and rigorous benchmark investigation on density functionals for the class is still lacking. To close this gap, we present a comprehensive benchmark study of quantum chemical methods on a series of classical and nonclassical carbocations, the CARBO33 dataset. We evaluate a total of 107 DFT methods from all rungs giving particular attention to double hybrid density functionals as the potential of the class has been largely undermined in the context of carbocations. To support our findings, DLPNO-CCSD(T) at the complete basis set (CBS) limit and W1-F12 are used as reference methods. Our results indicate that the composite CBS-QB3 method performs poorly and should not be adopted for target energies. Oftentimes, the tested DFAs of a lower rung perform better than several DFAs in a higher rung of Perdew's "Jacob's ladder". Nonetheless, double hybrids DSD-PBEP86-NL and ωB97X-2-D3(BJ) stand out by showing the overall best performance. Among the hybrids evaluated, about half of them show mean absolute deviation (MAD) below 1.1 kcal mol-1, including the popular hybrids M06-2X and mPW1PW91. In this family, MN15-D3(BJ) performs particularly well (MAD = 0.77 kcal mol-1) displaying reliable results across various tests. Highly popular B3LYP exhibited one of the worst performances (MAD = 4.74 kcal mol-1), and we do not recommend its application to carbocations. We also assess the 24 general-purpose basis sets of single- up to quadruple-ζ quality. The best compromise between accuracy and computational cost is achieved with cc-pVTZ followed by def2-TZVP. Computations on larger structures of general interest, including terpene carbocations, are also presented for selected DFT methods confirming general trends in the results.
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Affiliation(s)
- Marcelo T de Oliveira
- Department of Chemistry and Physics, La Trobe Institute of Molecular Sciences, La Trobe University, Melbourne, Victoria 3086, Australia. .,Chemistry Institute of São Carlos, University of São Paulo, Av. Trabalhador São Carlense 400, 13566-590, São Carlos, SP, Brazil
| | - Júlia M A Alves
- Chemistry Institute of São Carlos, University of São Paulo, Av. Trabalhador São Carlense 400, 13566-590, São Carlos, SP, Brazil
| | - Natália L Vrech
- Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Ataualpa A C Braga
- Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes 748, 05508-000, São Paulo, SP, Brazil
| | - Cristina A Barboza
- Faculty of Chemistry, Wrocław University of Science and Technology, Wrocław, Poland.,Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, Warsaw, Poland
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13
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Tong Y, Ma X, Hu T, Chen K, Cui G, Su P, Xu H, Gao W, Jiang T, Huang L. Structural and mechanistic insights into the precise product synthesis by a bifunctional miltiradiene synthase. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:165-175. [PMID: 36161753 PMCID: PMC9829396 DOI: 10.1111/pbi.13933] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 07/22/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Selaginella moellendorffii miltiradiene synthase (SmMDS) is a unique bifunctional diterpene synthase (diTPS) that catalyses the successive cyclization of (E,E,E)-geranylgeranyl diphosphate (GGPP) via (+)-copalyl diphosphate (CPP) to miltiradiene, which is a crucial precursor of important medicinal compounds, such as triptolide, ecabet sodium and carnosol. Miltiradiene synthetic processes have been studied in monofunctional diTPSs, while the precise mechanism by which active site amino acids determine product simplicity and the experimental evidence for reaction intermediates remain elusive. In addition, how bifunctional diTPSs work compared to monofunctional enzymes is attractive for detailed research. Here, by mutagenesis studies of SmMDS, we confirmed that pimar-15-en-8-yl+ is an intermediate in miltiradiene synthesis. Moreover, we determined the apo-state and the GGPP-bound state crystal structures of SmMDS. By structure analysis and mutagenesis experiments, possible contributions of key residues both in class I and II active sites were suggested. Based on the structural and functional analyses, we confirmed the copal-15-yl+ intermediate and unveiled more details of the catalysis process in the SmMDS class I active site. Moreover, the structural and experimental results suggest an internal channel for (+)-CPP produced in the class II active site moving towards the class I active site. Our research is a good example for intermediate identification of diTPSs and provides new insights into the product specificity determinants and intermediate transport, which should greatly facilitate the precise controlled synthesis of various diterpenes.
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Affiliation(s)
- Yuru Tong
- National Resource Center for Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijingChina
- School of Pharmaceutical SciencesCapital Medical UniversityBeijingChina
| | - Xiaoli Ma
- National Laboratory of BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
| | - Tianyuan Hu
- School of Pharmaceutical SciencesCapital Medical UniversityBeijingChina
| | - Kang Chen
- National Resource Center for Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijingChina
| | - Guanghong Cui
- National Resource Center for Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijingChina
| | - Ping Su
- National Resource Center for Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijingChina
| | - Haifeng Xu
- National Laboratory of BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Wei Gao
- Beijing Shijitan HospitalCapital Medical UniversityBeijingChina
| | - Tao Jiang
- National Laboratory of BiomacromoleculesInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Luqi Huang
- National Resource Center for Chinese Materia MedicaChina Academy of Chinese Medical SciencesBeijingChina
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14
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Soler J, Gergel S, Klaus C, Hammer SC, Garcia-Borràs M. Enzymatic Control over Reactive Intermediates Enables Direct Oxidation of Alkenes to Carbonyls by a P450 Iron-Oxo Species. J Am Chem Soc 2022; 144:15954-15968. [PMID: 35998887 PMCID: PMC9460782 DOI: 10.1021/jacs.2c02567] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
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The aerobic oxidation of alkenes to carbonyls is an important
and
challenging transformation in synthesis. Recently, a new P450-based
enzyme (aMOx) has been evolved in the laboratory to directly oxidize
styrenes to their corresponding aldehydes with high activity and selectivity.
The enzyme utilizes a heme-based, high-valent iron-oxo species as
a catalytic oxidant that normally epoxidizes alkenes, similar to other
catalysts. How the evolved aMOx enzyme suppresses the commonly preferred
epoxidation and catalyzes direct carbonyl formation is currently not
well understood. Here, we combine computational modelling together
with mechanistic experiments to study the reaction mechanism and unravel
the molecular basis behind the selectivity achieved by aMOx. Our results
describe that although both pathways are energetically accessible
diverging from a common covalent radical intermediate, intrinsic dynamic effects determine the strong preference for epoxidation.
We discovered that aMOx overrides these intrinsic preferences by controlling
the accessible conformations of the covalent radical intermediate.
This disfavors epoxidation and facilitates the formation of a carbocation
intermediate that generates the aldehyde product through a fast 1,2-hydride
migration. Electrostatic preorganization of the enzyme active site
also contributes to the stabilization of the carbocation intermediate.
Computations predicted that the hydride migration is stereoselective
due to the enzymatic conformational control over the intermediate
species. These predictions were corroborated by experiments using
deuterated styrene substrates, which proved that the hydride migration
is cis- and enantioselective. Our results demonstrate
that directed evolution tailored a highly specific active site that
imposes strong steric control over key fleeting biocatalytic intermediates,
which is essential for accessing the carbonyl forming pathway and
preventing competing epoxidation.
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Affiliation(s)
- Jordi Soler
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Carrer Maria Aurèlia Capmany 69, Girona 17003, Catalonia, Spain
| | - Sebastian Gergel
- Chair of Organic Chemistry and Biocatalysis, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Cindy Klaus
- Chair of Organic Chemistry and Biocatalysis, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Stephan C Hammer
- Chair of Organic Chemistry and Biocatalysis, Faculty of Chemistry, Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany
| | - Marc Garcia-Borràs
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química, Universitat de Girona, Carrer Maria Aurèlia Capmany 69, Girona 17003, Catalonia, Spain
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15
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Melville J, Hargis C, Davenport MT, Hamilton RS, Ess DH. Machine Learning Analysis of Dynamic‐Dependent Bond Formation in Trajectories with Consecutive Transition States. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jesse Melville
- Department of Chemistry and Biochemistry Brigham Young University Provo Utah USA
| | - Cal Hargis
- Department of Chemistry and Biochemistry Brigham Young University Provo Utah USA
| | - Michael T. Davenport
- Department of Chemistry and Biochemistry Brigham Young University Provo Utah USA
| | - R. Spencer Hamilton
- Department of Chemistry and Biochemistry Brigham Young University Provo Utah USA
| | - Daniel H. Ess
- Department of Chemistry and Biochemistry Brigham Young University Provo Utah USA
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16
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Lan J, Li X, Yang Y, Zhang X, Chung LW. New Insights and Predictions into Complex Homogeneous Reactions Enabled by Computational Chemistry in Synergy with Experiments: Isotopes and Mechanisms. Acc Chem Res 2022; 55:1109-1123. [PMID: 35385649 DOI: 10.1021/acs.accounts.1c00774] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Homogeneous catalysis and biocatalysis have been widely applied in synthetic, medicinal, and energy chemistry as well as synthetic biology. Driven by developments of new computational chemistry methods and better computer hardware, computational chemistry has become an essentially indispensable mechanistic "instrument" to help understand structures and decipher reaction mechanisms in catalysis. In addition, synergy between computational and experimental chemistry deepens our mechanistic understanding, which further promotes the rational design of new catalysts. In this Account, we summarize new or deeper mechanistic insights (including isotope, dispersion, and dynamical effects) into several complex homogeneous reactions from our systematic computational studies along with subsequent experimental studies by different groups. Apart from uncovering new mechanisms in some reactions, a few computational predictions (such as excited-state heavy-atom tunneling, steric-controlled enantioswitching, and a new geminal addition mechanism) based on our mechanistic insights were further verified by ensuing experiments.The Zimmerman group developed a photoinduced triplet di-π-methane rearrangement to form cyclopropane derivatives. Recently, our computational study predicted the first excited-state heavy-atom (carbon) quantum tunneling in one triplet di-π-methane rearrangement, in which the reaction rates and 12C/13C kinetic isotope effects (KIEs) can be enhanced by quantum tunneling at low temperatures. This unprecedented excited-state heavy-atom tunneling in a photoinduced reaction has recently been verified by an experimental 12C/13C KIE study by the Singleton group. Such combined computational and experimental studies should open up opportunities to discover more rare excited-state heavy-atom tunneling in other photoinduced reactions. In addition, we found unexpectedly large secondary KIE values in the five-coordinate Fe(III)-catalyzed hetero-Diels-Alder pathway, even with substantial C-C bond formation, due to the non-negligible equilibrium isotope effect (EIE) derived from altered metal coordination. Therefore, these KIE values cannot reliably reflect transition-state structures for the five-coordinate metal pathway. Furthermore, our density functional theory (DFT) quasi-classical molecular dynamics (MD) simulations demonstrated that the coordination mode and/or spin state of the iron metal as well as an electric field can affect the dynamics of this reaction (e.g., the dynamically stepwise process, the entrance/exit reaction channels).Moreover, we unveiled a new reaction mechanism to account for the uncommon Ru(II)-catalyzed geminal-addition semihydrogenation and hydroboration of silyl alkynes. Our proposed key gem-Ru(II)-carbene intermediates derived from double migrations on the same alkyne carbon were verified by crossover experiments. Additionally, our DFT MD simulations suggested that the first hydrogen migration transition-state structures may directly and quickly form the key gem-Ru-carbene structures, thereby "bypassing" the second migration step. Furthermore, our extensive study revealed the origin of the enantioselectivity of the Cu(I)-catalyzed 1,3-dipolar cycloaddition of azomethine ylides with β-substituted alkenyl bicyclic heteroarenes enabled by dual coordination of both substrates. Such mechanistic insights promoted our computational predictions of the enantioselectivity reversal for the corresponding monocyclic heteroarene substrates and the regiospecific addition to the less reactive internal C═C bond of one diene substrate. These predictions were proven by our experimental collaborators. Finally, our mechanistic insights into a few other reactions are also presented. Overall, we hope that these interactive computational and experimental studies enrich our mechanistic understanding and aid in reaction development.
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Affiliation(s)
- Jialing Lan
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China
- Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Xin Li
- Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Yuhong Yang
- Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Xiaoyong Zhang
- Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Lung Wa Chung
- Shenzhen Grubbs Institute, Department of Chemistry, and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
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17
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Liang J, Merrill AT, Laconsay CJ, Hou A, Pu Q, Dickschat JS, Tantillo DJ, Wang Q, Peters RJ. Deceptive Complexity in Formation of Cleistantha-8,12-diene. Org Lett 2022; 24:2646-2649. [PMID: 35385666 PMCID: PMC9040526 DOI: 10.1021/acs.orglett.2c00680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A barley diterpene synthase (HvKSL4) was found to produce (14S)-cleistantha-8,12-diene (1). Formation of the nearly planar cyclohexa-1,4-diene configuration leaves the ring poised for aromatization, but necessitates a deceptively complicated series of rearrangements steered through a complex energetic landscape, as elucidated here through quantum chemical calculations and labeling studies.
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Affiliation(s)
- Jin Liang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan 611130, China.,Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, Iowa 50011, United States
| | - Amy T Merrill
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Croix J Laconsay
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Anwei Hou
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms Universität Bonn, 53121 Bonn, Germany
| | - Qingyu Pu
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Jeroen S Dickschat
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms Universität Bonn, 53121 Bonn, Germany
| | - Dean J Tantillo
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Qiang Wang
- State Key Laboratory of Crop Gene Exploration and Utilization in Southwest China, College of Agronomy, Sichuan Agricultural University, Chengdu, Sichuan 611130, China
| | - Reuben J Peters
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, Iowa 50011, United States
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18
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Jamieson CS, Ohashi M, Houk KN, Tang Y. Computational Prediction and Experimental Validation of a Bridged Cation Intermediate in Akanthomycin Biosynthesis. J Am Chem Soc 2022; 144:5280-5283. [PMID: 35297629 DOI: 10.1021/jacs.2c02288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here we report a computation-driven chemoenzymatic synthesis and biosynthesis of the natural product deoxyakanthomycin, an atropisomeric pyridone natural product that features a 7-membered carbocycle with five stereocenters, one of which a quaternary center. The one-step synthesis from a biosynthetic precursor is based on computational analysis that predicted a σ-bridged cation mediated cyclization mechanism to form deoxyakanthomycin. The σ-bridged cation rationalizes the observed substrate-controlled selectivity; diastereoselectivity arises from attack of water anti to the σ-bridging, as is generally found for σ-bridged cations. Our studies also reveal a unifying biosynthetic strategy for 2-pyridone natural products that derive from a common o-quinone methide to create diverse structures.
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Affiliation(s)
- Cooper S Jamieson
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Masao Ohashi
- Department of Chemical and Biomolecular Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Yi Tang
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States.,Department of Chemical and Biomolecular Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
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19
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Tsutsumi T, Ono Y, Taketsugu T. Reaction Space Projector (ReSPer) for Visualizing Dynamic Reaction Routes Based on Reduced-Dimension Space. Top Curr Chem (Cham) 2022; 380:19. [PMID: 35266073 DOI: 10.1007/s41061-022-00377-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/21/2022] [Indexed: 11/26/2022]
Abstract
To analyze chemical reaction dynamics based on a reaction path network, we have developed the "Reaction Space Projector" (ReSPer) method with the aid of the dimensionality reduction method. This program has two functions: the construction of a reduced-dimensionality reaction space from a molecular structure dataset, and the projection of dynamic trajectories into the low-dimensional reaction space. In this paper, we apply ReSPer to isomerization and bifurcation reactions of the Au5 cluster and succeed in analyzing dynamic reaction routes involved in multiple elementary reaction processes, constructing complicated networks (called "closed islands") of nuclear permutation-inversion (NPI) isomerization reactions, and elucidating dynamic behaviors in bifurcation reactions with reference to bundles of trajectories. Interestingly, in the second application, we find a correspondence between the contribution ratios in the ability to visualize and the symmetry of the morphology of closed islands. In addition, the third application suggests the existence of boundaries that determine the selectivity in bifurcation reactions, which was discussed in the phase space. The ReSPer program is a versatile and robust tool to clarify dynamic reaction mechanisms based on the reduced-dimensionality reaction space without prior knowledge of target reactions.
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Affiliation(s)
- Takuro Tsutsumi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Yuriko Ono
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, 001-0021, Japan
| | - Tetsuya Taketsugu
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan.
- Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo, 001-0021, Japan.
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20
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21
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Gao B, Yu X, Wang T, Gong H, Fan X, Xue H, Jiang C, Chang K, Huang X, He J. Promoting charge separation by rational integration of a covalent organic framework on a BiVO 4 photoanode. Chem Commun (Camb) 2022; 58:1796-1799. [PMID: 35040459 DOI: 10.1039/d1cc07047a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the first time, covalent organic frameworks (COF-TpPa and COF-TpPaC) are selected to combine with the BiVO4 photoanode through a covalent bond. The heterojunction and covalent connection of COFs and BiVO4 can promote the separation of carriers, and the -CH3 on the benzene ring in COF-TpPaC as an electron donor group can increase the carrier concentration of the photoanode. As a result, the TpPaC/BiVO4 photoanode shows the best performance. This covalent hybridization strategy opens a new insight into the development of COF-modified photoanodes.
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Affiliation(s)
- Bin Gao
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Xingyu Yu
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Tao Wang
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Hao Gong
- Department of Chemistry and Materials Science, College of Science, Nanjing Forestry University, Nanjing 210037, P. R. China
| | - Xiaoli Fan
- School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing 211167, P. R. China
| | - Hairong Xue
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Cheng Jiang
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Kun Chang
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Xianli Huang
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
| | - Jianping He
- College of Materials Science and Technology, Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, P. R. China.
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22
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Ito T, Maeda S, Harabuchi Y. Kinetic Analysis of a Reaction Path Network Including Ambimodal Transition States: A Case Study of an Intramolecular Diels-Alder Reaction. J Chem Theory Comput 2022; 18:1663-1671. [PMID: 35099971 DOI: 10.1021/acs.jctc.1c01297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This study proposes a methodology for the kinetic analysis of a reaction path network including ambimodal transition states (TSs), through which an ensemble of trajectories bifurcates to multiple minima in a phenomenon called dynamical bifurcation. The proposed methodology consists of three techniques: an automated reaction path search to construct a reaction path network including ambimodal TSs, an ab initio molecular dynamics simulation to evaluate the branching ratio, and the definition of rate constants incorporating this ratio. Applying the procedure to a Diels-Alder reaction, it was found that the inclusion of dynamical bifurcations is necessary to explain the experimental reaction yield of a byproduct. In addition, it was verified that the products take 1013 s to reach thermal equilibrium and that the experimental selectivity is determined by the dynamical bifurcations.
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Affiliation(s)
- Takuma Ito
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-8628, Japan
| | - Satoshi Maeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan.,Japan Science and Technology Agency (JST), Exploratory Research for Advanced Technology (ERATO) Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Sapporo 060-0810, Japan
| | - Yu Harabuchi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.,Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), Hokkaido University, Sapporo 001-0021, Japan.,Japan Science and Technology Agency (JST), Exploratory Research for Advanced Technology (ERATO) Maeda Artificial Intelligence for Chemical Reaction Design and Discovery Project, Sapporo 060-0810, Japan
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23
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Zhu M, Zheng C. Post-spin crossing dynamics determine the regioselectivity in open-shell singlet biradical recombination. Org Chem Front 2022. [DOI: 10.1039/d1qo01757h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Comprehensive computational studies reveal unique dynamic effects in a multi-spin-state reaction that determine the regioselectivity of a biradical recombination process.
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Affiliation(s)
- Min Zhu
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
- School of Physical Science and Technology, ShanghaiTech University, 100 Haike Road, Shanghai 201210, China
| | - Chao Zheng
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China
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24
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Bharadwaz P, Maldonado-Domínguez M, Srnec M. Bifurcating reactions: distribution of products from energy distribution in a shared reactive mode. Chem Sci 2021; 12:12682-12694. [PMID: 34703554 PMCID: PMC8494029 DOI: 10.1039/d1sc02826j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/21/2021] [Indexed: 11/21/2022] Open
Abstract
Bifurcating reactions yield two different products emerging from one single transition state and are therefore archetypal examples of reactions that cannot be described within the framework of the traditional Eyring's transition state theory (TST). With the growing number and importance of these reactions in organic and biosynthetic chemistry, there is also an increasing demand for a theoretical tool that would allow for the accurate quantification of reaction outcome at low cost. Here, we introduce such an approach that fulfils these criteria, by evaluating bifurcation selectivity through the energy distribution within the reactive mode of the key transition state. The presented method yields an excellent agreement with experimentally reported product ratios and predicts the correct selectivity for 89% of nearly 50 various cases, covering pericyclic reactions, rearrangements, fragmentations and metal-catalyzed processes as well as a series of trifurcating reactions. With 71% of product ratios determined within the error of less than 20%, we also found that the methodology outperforms three other tested protocols introduced recently in the literature. Given its predictive power, the procedure makes reaction design feasible even in the presence of complex non-TST chemical steps. Reactive Mode Composition Factor (RMCF) analysis is a powerful tool to forecast the product distribution of bifurcating reactions through analysis of the kinetic energy distribution within the first transition state traversed by the reacting system.![]()
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Affiliation(s)
- Priyam Bharadwaz
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences Dolejškova 3 Prague 8 18223 Czech Republic
| | - Mauricio Maldonado-Domínguez
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences Dolejškova 3 Prague 8 18223 Czech Republic
| | - Martin Srnec
- J. Heyrovský Institute of Physical Chemistry, The Czech Academy of Sciences Dolejškova 3 Prague 8 18223 Czech Republic
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25
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The dynamical significance of valley-ridge inflection points. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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Zou Y, Houk KN. Mechanisms and Dynamics of Synthetic and Biosynthetic Formation of Delitschiapyrones: Solvent Control of Ambimodal Periselectivity. J Am Chem Soc 2021; 143:11734-11740. [PMID: 34297552 PMCID: PMC9307257 DOI: 10.1021/jacs.1c05293] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The mechanism and dynamics for the formation of the delitschiapyrone family of natural products are studied by density functional theory (DFT) calculations and quasiclassical molecular dynamics simulations with DFT and xTB. In the uncatalyzed reaction, delitschiapyrones A and B are formed by Diels-Alder reactions through a single transition state and a post-transition state bifurcation that favors formation of delitschiapyrone B. In water and most likely in the enzyme, the acidic hydroxyquinone ionizes, and the resulting conjugate base undergoes cycloaddition preferentially to delitschiapyrone A. We demonstrate a new type of biosynthetic transformation and variable selectivity from a (4 + 2)/(4 + 3) ambimodal transition state.
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Affiliation(s)
- Yike Zou
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
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27
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Liu Y, Holm S, Meisner J, Jia Y, Wu Q, Woods TJ, Martinez TJ, Moore JS. Flyby reaction trajectories: Chemical dynamics under extrinsic force. Science 2021; 373:208-212. [PMID: 34244412 DOI: 10.1126/science.abi7609] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 06/03/2021] [Indexed: 11/02/2022]
Abstract
Dynamic effects are an important determinant of chemical reactivity and selectivity, but the deliberate manipulation of atomic motions during a chemical transformation is not straightforward. Here, we demonstrate that extrinsic force exerted upon cyclobutanes by stretching pendant polymer chains influences product selectivity through force-imparted nonstatistical dynamic effects on the stepwise ring-opening reaction. The high product stereoselectivity is quantified by carbon-13 labeling and shown to depend on external force, reactant stereochemistry, and intermediate stability. Computational modeling and simulations show that, besides altering energy barriers, the mechanical force activates reactive intramolecular motions nonstatistically, setting up "flyby trajectories" that advance directly to product without isomerization excursions. A mechanistic model incorporating nonstatistical dynamic effects accounts for isomer-dependent mechanochemical stereoselectivity.
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Affiliation(s)
- Yun Liu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Soren Holm
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.,The PULSE Institute, Stanford University, Stanford, CA 94305, USA.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jan Meisner
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA.,The PULSE Institute, Stanford University, Stanford, CA 94305, USA.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Yuan Jia
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Qiong Wu
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Toby J Woods
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.,3M Materials Chemistry Laboratory, School of Chemical Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Todd J Martinez
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA. .,The PULSE Institute, Stanford University, Stanford, CA 94305, USA.,SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
| | - Jeffrey S Moore
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA. .,Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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28
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Maley SM, Melville J, Yu S, Teynor MS, Carlsen R, Hargis C, Hamilton RS, Grant BO, Ess DH. Machine learning classification of disrotatory IRC and conrotatory non-IRC trajectory motion for cyclopropyl radical ring opening. Phys Chem Chem Phys 2021; 23:12309-12320. [PMID: 34018524 DOI: 10.1039/d1cp00612f] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quasiclassical trajectory analysis is now a standard tool to analyze non-minimum energy pathway motion of organic reactions. However, due to the large amount of information associated with trajectories, quantitative analysis of the dynamic origin of reaction selectivity is complex. For the electrocyclic ring opening of cyclopropyl radical, more than 4000 trajectories were run showing that allyl radicals are formed through a mixture of disrotatory intrinsic reaction coordinate (IRC) motion as well as conrotatory non-IRC motion. Geometric, vibrational mode, and atomic velocity transition-state features from these trajectories were used for supervised machine learning analysis with classification algorithms. Accuracy >80% with a random forest model enabled quantitative and qualitative assessment of transition-state trajectory features controlling disrotatory IRC versus conrotatory non-IRC motion. This analysis revealed that there are two key vibrational modes where their directional combination provides prediction of IRC versus non-IRC motion.
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Affiliation(s)
- Steven M Maley
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Jesse Melville
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Spencer Yu
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Matthew S Teynor
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Ryan Carlsen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Cal Hargis
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - R Spencer Hamilton
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Benjamin O Grant
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
| | - Daniel H Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, USA.
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29
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Sun Q, Lu X, Tantillo DJ. Dynamic Effects in Intramolecular Schmidt Reactions: Entropy, Electrostatic Drag, and Selectivity Prediction. Chemphyschem 2021; 22:649-656. [PMID: 33567140 DOI: 10.1002/cphc.202100033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Indexed: 12/16/2022]
Abstract
Electrostatic drag in the intramolecular Schmidt reactions of azidopropylcyclohexanones is characterized using density functional theory (DFT) calculations and direct dynamics simulations. Despite resulting from enthalpically favorable interactions, electrostatic drag slows down N2 loss during formation of bridged lactam products, an effect with implications for controlling product selectivity.
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Affiliation(s)
- Qing Sun
- Key Laboratory of Jiangxi Province for Persistent Pollutants Control and Resources Recycle, Nanchang Hangkong University, Nanchang, 330063, China
| | - Xin Lu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Dean J Tantillo
- Department of Chemistry, University of California, Davis, CA 95616, USA
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30
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Tantillo DJ. Dynamic effects on organic reactivity—Pathways to (and from) discomfort. J PHYS ORG CHEM 2021. [DOI: 10.1002/poc.4202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Dean J. Tantillo
- Department of Chemistry University of California, Davis Davis California USA
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31
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Jamieson CS, Sengupta A, Houk KN. Cycloadditions of Cyclopentadiene and Cycloheptatriene with Tropones: All Endo-[6+4] Cycloadditions Are Ambimodal. J Am Chem Soc 2021; 143:3918-3926. [PMID: 33656318 DOI: 10.1021/jacs.0c13401] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The cycloadditions of cyclopentadiene and cycloheptatriene with tropone are some of the earliest published examples of [6+4] cycloaddition reactions. We report quantum mechanical studies (ωB97X-D and DLPNO-CCSD(T)) of transition structures and products of these reactions, as well as quasi-classical molecular dynamics simulations of reaction trajectories. The study reveals that these cycloadditions involve ambimodal transition states resulting in a web of products by pericyclic interconversion pathways. Combined with these studies, calculations of simple parent systems and a thorough meta-analysis of literature examples reveal the general concept that all endo-[6+4] cycloadditions are ambimodal.
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Affiliation(s)
- Cooper S Jamieson
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Arkajyoti Sengupta
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
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32
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Feng Z, Tantillo DJ. Dynamic Effects on Migratory Aptitudes in Carbocation Reactions. J Am Chem Soc 2021; 143:1088-1097. [PMID: 33400509 DOI: 10.1021/jacs.0c11850] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Carbocation rearrangement reactions are of great significance to synthetic and biosynthetic chemistry. In pursuit of a scale of inherent migratory aptitude that takes into account dynamic effects, both uphill and downhill ab initio molecular dynamics (AIMD) simulations were used to examine competing migration events in a model system designed to remove steric and electronic biases. The results of these simulations were combined with detailed investigations of potential energy surface topography and variational transition state theory calculations to reveal the importance of nonstatistical dynamic effects on migratory aptitude.
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Affiliation(s)
- Zhitao Feng
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
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33
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Politano F, Sandoval AL, Uranga JG, Buján EI, Leadbeater NE. Using experimental and computational approaches to probe an unusual carbon-carbon bond cleavage observed in the synthesis of benzimidazole N-oxides. Org Biomol Chem 2021; 19:208-215. [PMID: 33179700 DOI: 10.1039/d0ob01797c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Experimental and computational studies have been performed in order to investigate an unusual carbon-carbon bond cleavage that occurs in the preparation of certain benzimidazole N-oxides from anilines. The key factor determining the outcome of the reaction was found to be the substituents on the amine functionality of the aniline.
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Affiliation(s)
- Fabrizio Politano
- Department of Chemistry, University of Connecticut, 55 North Eagleville Road, Storrs, Connecticut 06269, USA.
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34
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De S, Mahal E, Haque MA, Jana CK, Koley D. Computational Investigation of Multifaceted Cationic Rearrangement and Stereo- and Regioselectivity in the Formation of Dysideanone's Analogues. J Org Chem 2021; 86:1133-1140. [PMID: 33331777 DOI: 10.1021/acs.joc.0c02609] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mechanistic studies of regiodivergent arylations of cycloalkanols to furnish enantioenriched dysideanone's analogues are performed by employing density functional theory (DFT) calculations (B3LYP-D3(SMD)/6-311++G**//B3LYP-D3/6-31+G** level of theory). On the basis of our calculations, remote γ'-C-H arylation is preferred for unsubstituted carbinol 1, an outcome from combined factors like carbocationic stability, less steric hindrance during C-C coupling, and facile dearomatization. Meanwhile, in the presence of dimethyl substituent 1Me, regioselective γ-arylation is favored by 3.4 kcal/mol, and both findings are in agreement with the reported experimental observations. Most importantly, we concur that the barrier associated with the formation of carbocation 6 and its substituted analogues correlates with the C-H arylation outcomes. Furthermore, the β-arylation route remains unlikely for all the reaction pathways explored in this study.
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Affiliation(s)
- Sriman De
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741 246, India
| | - Eti Mahal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741 246, India
| | - Md Ashraful Haque
- Department of Chemistry, Indian Institute of Technology (IIT) Guwahati, Guwahati 781 039, India
| | - Chandan K Jana
- Department of Chemistry, Indian Institute of Technology (IIT) Guwahati, Guwahati 781 039, India
| | - Debasis Koley
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741 246, India
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35
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Zheng C. Divergent Pathways and Dynamic Effects of Intramolecular Hydride Transfer Reactions Mediated by Cp*M(
III
) Complexes (M = Co, Rh, Ir)
†. CHINESE J CHEM 2020. [DOI: 10.1002/cjoc.202000253] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Chao Zheng
- State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences 345 Lingling Lu Shanghai 200032 China
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36
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Feng Q, Wu H, Li X, Song L, Chung LW, Wu YD, Sun J. Ru-Catalyzed Geminal Hydroboration of Silyl Alkynes via a New gem-Addition Mechanism. J Am Chem Soc 2020; 142:13867-13877. [DOI: 10.1021/jacs.0c05334] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Qiang Feng
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
| | - Haonan Wu
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
- Lab of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
| | - Xin Li
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
| | - Lijuan Song
- Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Lung Wa Chung
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen 518055, China
| | - Yun-Dong Wu
- Lab of Computational Chemistry and Drug Design, State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, China
- Shenzhen Bay Laboratory, Shenzhen 518055, China
- College of Chemistry, Peking University, Beijing 100871, China
| | - Jianwei Sun
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, SAR, China
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37
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Roytman VA, Singleton DA. Solvation Dynamics and the Nature of Reaction Barriers and Ion-Pair Intermediates in Carbocation Reactions. J Am Chem Soc 2020; 142:12865-12877. [DOI: 10.1021/jacs.0c06295] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Vladislav A. Roytman
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842, United States
| | - Daniel A. Singleton
- Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842, United States
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38
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Chuang HH, Tantillo DJ, Hsu CP. Construction of Two-Dimensional Potential Energy Surfaces of Reactions with Post-Transition-State Bifurcations. J Chem Theory Comput 2020; 16:4050-4060. [PMID: 32470303 DOI: 10.1021/acs.jctc.0c00172] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions with post-transition-state bifurcations (PTSBs) involve initial ambimodal transition-state structures followed by an unstable region leading to two possible products. PTSBs are seen in many organic, organometallic, and biosynthetic reactions, but analyzing the origins of selectivity for these reactions is challenging, in large part due to the complex nature of the potential energy surfaces involved, which precludes analyses based on single intrinsic reaction coordinate (IRC; steepest-descent path in mass-weighted coordinate). While selectivity can be predicted using molecular dynamics simulation, connecting results from such calculations to the topography of potential energy surfaces is difficult. In the present work, a method for generating two-dimensional potential energy surfaces for PTSBs is described. The first dimension starts with the IRC for the first transition-state structure, followed by a modified reaction coordinate that reaches the second transition-state structure, which interconverts the two products of a bifurcating reaction path. The IRC for the second transition-state structure constitutes the second dimension. In addition, a method for mapping trajectories from Born-Oppenheimer molecular dynamics simulations onto these surfaces is described. Both approaches are illustrated with representative examples from the field of organic chemistry. The 2D-PESs for five asymmetric cases tested have clear tilted topography after the first transition-state structure, and the tilted direction correlates well with the selectivity observed from previous dynamic simulation. Instead of selecting reaction coordinates by chemical intuition, our method provides a general means to construct two-dimensional potential energy surfaces for reactions with post-transition-state bifurcations.
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Affiliation(s)
- Hsiao-Han Chuang
- Department of Chemistry, National Taiwan University, 11529 Taipei, Taiwan.,Institute of Chemistry, Academia Sinica, 11529 Taipei, Taiwan.,Nanoscience and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, 11529 Taipei, Taiwan
| | - Dean J Tantillo
- Department of Chemistry, University of California-Davis, Davis, California 95616, United States
| | - Chao-Ping Hsu
- Institute of Chemistry, Academia Sinica, 11529 Taipei, Taiwan
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39
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Rollins N, Pugh SL, Maley SM, Grant BO, Hamilton RS, Teynor MS, Carlsen R, Jenkins JR, Ess DH. Machine Learning Analysis of Direct Dynamics Trajectory Outcomes for Thermal Deazetization of 2,3-Diazabicyclo[2.2.1]hept-2-ene. J Phys Chem A 2020; 124:4813-4826. [PMID: 32412755 DOI: 10.1021/acs.jpca.9b10410] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Experimentally, the thermal gas-phase deazetization of 2,3-diazabicyclo[2.2.1]hept-2-ene (1) results in the loss of N2 and the formation of bicyclo products 3 (exo) and 4 (endo) in a nonstatistical ratio, with preference for the exo product. Here, we report unrestricted M06-2X quasiclassical trajectories initialized from the concerted N2 ejection transition state that were able to replicate the experimental preference to form 3. We found that the 3:4 ratio results from the relative amounts of very fast (ballistic) exotype trajectories versus trajectories that lead to the 1,3-diradical intermediate 2. These quasiclassical trajectories provided a set of transition-state vibrational, velocity, momenta, and geometric features for the machine learning analysis. A selection of popular supervised classification algorithms (e.g., random forest) provided poor prediction of trajectory outcomes based on only transition-state vibrational quanta and energy features. However, these machine learning models provided more accurate predictions using atomic velocities and atomic positions, attaining ∼70% accuracy using initial conditions and between 85 and 95% accuracy at later reaction time steps. This increased accuracy allowed the feature importance analysis to reveal that, at the later-time analysis, the methylene bridge out-of-plane bending is correlated with trajectory outcomes for the formation of either the exo product or toward the diradical intermediate. Possible reasons for the struggle of machine learning algorithms to classify trajectories based on transition-state features is the heavily overlapping feature values, the finite but very large possible vibrational mode combinations, and the possibility of chaos as trajectories propagate. We examined this chaos by comparing a set of nearly identical trajectories that differed by only a very small scaling of the kinetic energies resulting from the transition-state reaction coordinate.
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Affiliation(s)
- Nick Rollins
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Samuel L Pugh
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Steven M Maley
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Benjamin O Grant
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - R Spencer Hamilton
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Matthew S Teynor
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Ryan Carlsen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Jordan R Jenkins
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Daniel H Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
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40
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Lee S, Goodman JM. Rapid Route-Finding for Bifurcating Organic Reactions. J Am Chem Soc 2020; 142:9210-9219. [DOI: 10.1021/jacs.9b13449] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Sanha Lee
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Jonathan M. Goodman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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41
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Abstract
Roaming reactions were first clearly identified in photodissociation of formaldehyde 15 years ago, and roaming dynamics are now recognized as a universal aspect of chemical reactivity. These reactions typically involve frustrated near-dissociation of a quasibound system to radical fragments, followed by reorientation at long range and intramolecular abstraction. The consequences can be unexpected formation of molecular products, depletion of the radical pool in chemical systems, and formation of products with unusual internal state distributions. In this review, I examine some current aspects of roaming reactions with an emphasis on experimental results, focusing on possible quantum effects in roaming and roaming dynamics in bimolecular systems. These considerations lead to a more inclusive definition of roaming reactions as those for which key dynamics take place at long range.
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Affiliation(s)
- Arthur G. Suits
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211, USA
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42
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Yang Y, Zhang X, Zhong LP, Lan J, Li X, Li CC, Chung LW. Unusual KIE and dynamics effects in the Fe-catalyzed hetero-Diels-Alder reaction of unactivated aldehydes and dienes. Nat Commun 2020; 11:1850. [PMID: 32296076 PMCID: PMC7160212 DOI: 10.1038/s41467-020-15599-w] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 03/13/2020] [Indexed: 12/30/2022] Open
Abstract
Hetero-Diels-Alder (HDA) reaction is an important synthetic method for many natural products. An iron(III) catalyst was developed to catalyze the challenging HDA reaction of unactivated aldehydes and dienes with high selectivity. Here we report extensive density-functional theory (DFT) calculations and molecular dynamics simulations that show effects of iron (including its coordinate mode and/or spin state) on the dynamics of this reaction: considerably enhancing dynamically stepwise process, broadening entrance channel and narrowing exit channel from concerted asynchronous transition states. Also, our combined computational and experimental secondary KIE studies reveal unexpectedly large KIE values for the five-coordinate pathway even with considerable C-C bond forming, due to equilibrium isotope effect from the change in the metal coordination. Moreover, steric and electronic effects are computationally shown to dictate the C=O chemoselectivity for an α,β-unsaturated aldehyde, which is verified experimentally. Our mechanistic study may help design homogeneous, heterogeneous and biological catalysts for this challenging reaction.
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Affiliation(s)
- Yuhong Yang
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xiaoyong Zhang
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Li-Ping Zhong
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Jialing Lan
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Xin Li
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Lung Wa Chung
- Shenzhen Grubbs Institute, Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.
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43
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Teynor MS, Carlsen R, Ess DH. Relationship Between Energy Landscape Shape and Dynamics Trajectory Outcomes for Methane C–H Activation by Cationic Cp*(PMe3)Ir/Rh/Co(CH3). Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00108] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Matthew S. Teynor
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Ryan Carlsen
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
| | - Daniel H. Ess
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, Utah 84602, United States
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44
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Laconsay CJ, Tsui KY, Tantillo DJ. Tipping the balance: theoretical interrogation of divergent extended heterolytic fragmentations. Chem Sci 2020; 11:2231-2242. [PMID: 32190279 PMCID: PMC7059201 DOI: 10.1039/c9sc05161a] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/08/2020] [Indexed: 01/24/2023] Open
Abstract
Herein we interrogate a type of heterolytic fragmentation reaction called a 'divergent fragmentation' using density functional theory (DFT), natural bond orbital (NBO) analysis, ab initio molecular dynamics (AIMD), and external electric field (EEF) calculations. We demonstrate that substituents, electrostatic environment and non-statistical dynamic effects all influence product selectivity in reactions that involve divergent fragmentation pathways. Direct dynamics simulations reveal an unexpected post-transition state bifurcation (PTSB), and EEF calculations suggest that some transition states for divergent pathways can, in principle, be selectively stabilized if an electric field of the correct magnitude is oriented appropriately.
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Affiliation(s)
- Croix J Laconsay
- Department of Chemistry , University of California , Davis , CA 95616 , USA .
| | - Ka Yi Tsui
- Department of Chemistry , University of California , Davis , CA 95616 , USA .
| | - Dean J Tantillo
- Department of Chemistry , University of California , Davis , CA 95616 , USA .
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45
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Wheeler JI, Carlsen R, Ess DH. Mechanistic molecular motion of transition-metal mediated β-hydrogen transfer: quasiclassical trajectories reveal dynamically ballistic, dynamically unrelaxed, two step, and concerted mechanisms. Dalton Trans 2020; 49:7747-7757. [DOI: 10.1039/d0dt01687j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Quasiclassical direct dynamics reveal new dynamical mechanisms for metal-alkyl to ethylene β-hydrogen transfer.
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Affiliation(s)
- Josh I. Wheeler
- Department of Chemistry and Biochemistry
- Brigham Young University
- Provo
- USA
| | - Ryan Carlsen
- Department of Chemistry and Biochemistry
- Brigham Young University
- Provo
- USA
| | - Daniel H. Ess
- Department of Chemistry and Biochemistry
- Brigham Young University
- Provo
- USA
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46
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Ito T, Harabuchi Y, Maeda S. AFIR explorations of transition states of extended unsaturated systems: automatic location of ambimodal transition states. Phys Chem Chem Phys 2020; 22:13942-13950. [DOI: 10.1039/d0cp02379e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Based on the artificial force induced reaction (AFIR) method, we proposed a procedure to systematically explore ambimodal transition states (TSs) that cause the dynamical bifurcation.
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Affiliation(s)
- Takuma Ito
- Graduate School of Chemical Sciences and Engineering
- Hokkaido University
- Sapporo 060-8628
- Japan
| | - Yu Harabuchi
- Department of Chemistry
- Faculty of Science
- Hokkaido University
- Sapporo 060-0810
- Japan
| | - Satoshi Maeda
- Department of Chemistry
- Faculty of Science
- Hokkaido University
- Sapporo 060-0810
- Japan
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47
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Jamieson CS, Ohashi M, Liu F, Tang Y, Houk KN. The expanding world of biosynthetic pericyclases: cooperation of experiment and theory for discovery. Nat Prod Rep 2019; 36:698-713. [PMID: 30311924 DOI: 10.1039/c8np00075a] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Covering: 2000 to 2018 Pericyclic reactions are a distinct class of reactions that have wide synthetic utility. Before the recent discoveries described in this review, enzyme-catalyzed pericyclic reactions were not widely known to be involved in biosynthesis. This situation is changing rapidly. We define the scope of pericyclic reactions, give a historical account of their discoveries as biosynthetic reactions, and provide evidence that there are many enzymes in nature that catalyze pericyclic reactions. These enzymes, the "pericyclases," are the subject of this review.
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Affiliation(s)
- Cooper S Jamieson
- Department of Chemical and Biomolecular Engineering, Department of Chemistry and Biochemistry, University of California, Los Angeles 90095, USA.
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48
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Yoshida D, Takahashi K. Odd–Even Reactivity Variation Due to Dynamical Effects around the Roaming Saddle Points of the Reaction Between C n– Chain ( n = 2–8) and H 2. J Phys Chem A 2019; 123:5300-5308. [DOI: 10.1021/acs.jpca.9b03435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daisuke Yoshida
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, Republic of China
| | - Kaito Takahashi
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 10617, Republic of China
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49
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Pahima E, Zhang Q, Tiefenbacher K, Major DT. Discovering Monoterpene Catalysis Inside Nanocapsules with Multiscale Modeling and Experiments. J Am Chem Soc 2019; 141:6234-6246. [PMID: 30907083 DOI: 10.1021/jacs.8b13411] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Large-scale production of natural products, such as terpenes, presents a significant scientific and technological challenge. One promising approach to tackle this problem is chemical synthesis inside nanocapsules, although enzyme-like control of such chemistry has not yet been achieved. In order to better understand the complex chemistry inside nanocapsules, we design a multiscale nanoreactor simulation approach. The nanoreactor simulation protocol consists of hybrid quantum mechanics-molecular mechanics-based high temperature Langevin molecular dynamics simulations. Using this approach we model the tail-to-head formation of monoterpenes inside a resorcin[4]arene-based capsule (capsule I). We provide a rationale for the experimentally observed kinetics of monoterpene product formation and product distribution using capsule I, and we explain why additional stable monoterpenes, like camphene, are not observed. On the basis of the in-capsule I simulations, and mechanistic insights, we propose that feeding the capsule with pinene can yield camphene, and this proposal is verified experimentally. This suggests that the capsule may direct the dynamic reaction cascades by virtue of π-cation interactions.
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Affiliation(s)
- Efrat Pahima
- Department of Chemistry , Bar-Ilan University , Ramat-Gan 52900 , Israel
| | - Qi Zhang
- Department of Chemistry , University of Basel , Mattenstrasse 24a , 4058 Basel , Switzerland
| | - Konrad Tiefenbacher
- Department of Chemistry , University of Basel , Mattenstrasse 24a , 4058 Basel , Switzerland.,Department of Biosystems Science and Engineering , ETH Zurich , Mattenstrasse 24 , 4058 Basel , Switzerland
| | - Dan T Major
- Department of Chemistry , Bar-Ilan University , Ramat-Gan 52900 , Israel
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50
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Enzyme-catalysed [6+4] cycloadditions in the biosynthesis of natural products. Nature 2019; 568:122-126. [PMID: 30867595 DOI: 10.1038/s41586-019-1021-x] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 02/07/2019] [Indexed: 01/01/2023]
Abstract
Pericyclic reactions are powerful transformations for the construction of carbon-carbon and carbon-heteroatom bonds in organic synthesis. Their role in biosynthesis is increasingly apparent, and mechanisms by which pericyclases can catalyse reactions are of major interest1. [4+2] cycloadditions (Diels-Alder reactions) have been widely used in organic synthesis2 for the formation of six-membered rings and are now well-established in biosynthesis3-6. [6+4] and other 'higher-order' cycloadditions were predicted7 in 1965, and are now increasingly common in the laboratory despite challenges arising from the generation of a highly strained ten-membered ring system8,9. However, although enzyme-catalysed [6+4] cycloadditions have been proposed10-12, they have not been proven to occur. Here we demonstrate a group of enzymes that catalyse a pericyclic [6+4] cycloaddition, which is a crucial step in the biosynthesis of streptoseomycin-type natural products. This type of pericyclase catalyses [6+4] and [4+2] cycloadditions through a single ambimodal transition state, which is consistent with previous proposals11,12. The [6+4] product is transformed to a less stable [4+2] adduct via a facile Cope rearrangement, and the [4+2] adduct is converted into the natural product enzymatically. Crystal structures of three pericyclases, computational simulations of potential energies and molecular dynamics, and site-directed mutagenesis establish the mechanism of this transformation. This work shows how enzymes are able to catalyse concerted pericyclic reactions involving ambimodal transition states.
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