1
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Kuan KY, Hsu CP. Predicting Selectivity with a Bifurcating Surface: Inaccurate Model or Inaccurate Statistics of Dynamics? J Phys Chem A 2024; 128:6798-6805. [PMID: 39099446 PMCID: PMC11331512 DOI: 10.1021/acs.jpca.4c04039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2024] [Revised: 07/18/2024] [Accepted: 07/23/2024] [Indexed: 08/06/2024]
Abstract
Reactions on post-transition-state bifurcation (PTSB) energy surfaces are an important class of reaction in which classical rate theories, such as the transition state theory, fail to account for the selectivity. Quasiclassical trajectory molecular dynamic (QCT-MD) simulation is an important computational approach to understanding reactions mechanisms, especially for reactions that cannot be predicted from conventional rate theories. However, the applicability of direct dynamic simulations is hampered by huge computational costs for collecting a statistically meaningful set of trajectories, making it difficult to compare simulation results with theoretical or physical insights-based predictions (non-MD predictions). In this work, we examine the PTSB of Schmidt-Aubé reactions studied by Tantillo and co-workers. With machine-learning using kernel-ridge regression (KRR) to predict atomic forces, statistical reliability was enhanced by significantly increasing the number of trajectories. With KRR, the bottleneck of simulating dynamics (atomic forces in QCT-MD with density functional theory) was accelerated more than 100-fold. We found that this KRR-aided QCT-MD approach is successful in predicting branching ratios with a much larger number of trajectories. With our approach, statistical errors are greatly reduced, and hypothetical non-MD models for predicting selectivity are tested with much higher confidence. By comparison with non-MD models, dynamical properties that affect branching ratios become more clearly described.
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Affiliation(s)
- Kai-Yuan Kuan
- Institute
of Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Chao-Ping Hsu
- Institute
of Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
- Physics
Division, National Center for Theoretical
Sciences, 1, Section
4, Roosevelt Road, Taipei 106, Taiwan
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2
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Kadiyam RK, Sangolkar AA, Faizan M, Pawar R. Bispericyclic Ambimodal Dimerization of Pentafulvene: The Origin of Asynchronicity and Kinetic Selectivity of the Endo Transition State. J Org Chem 2024; 89:6813-6825. [PMID: 38661667 DOI: 10.1021/acs.joc.4c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The propensity of fulvenes to undergo dimerization has long been known, although the in-depth mechanism and electronic behavior during dimerization are still elusive. Herein, we made an attempt to gain insights into the reactivity of pentafulvene for Diels-Alder (DA) and [6 + 4]-cycloadditions via conventional and ambimodal routes. The result emphasizes that pentafulvene dimerization preferentially proceeds through a unique bifurcation mechanism where two DA pathways merge together to produce two degenerate [4 + 2]-cycloadducts from a single TS. Despite the [6 + 4]-cycloadduct being thermodynamically preferred, [4 + 2]-cycloaddition reactions are kinetically driven. Singlet biradicaloid is involved in through-space 6e- delocalization as a secondary orbital interaction that originates asynchronicity and stabilizes the bispericyclic transition state (TS). The transformation of various actively participating intrinsic bonding orbitals (IBOs) unambiguously forecasts the formation of multiple products from a single TS and rationalizes the mechanism of ambimodal reactions that are rather difficult to probe with other analyses. The changes in active IBOs clearly distinguish the conventional reactions from bifurcation reactions and can be employed to characterize and confirm the ambimodal mechanism. This report gains a crucial theoretical insight into the mechanism of bifurcation, the origin of asynchronicity, and electronic behavior in ambimodal TS, which will certainly be of enormous value for future studies.
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Affiliation(s)
- Rama Krishna Kadiyam
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
| | - Akanksha Ashok Sangolkar
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
| | - Mohmmad Faizan
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
| | - Ravinder Pawar
- Laboratory of Advanced Computation and Theory for Materials and Chemistry, Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana 506004, India
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3
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Feng Z, Guo W, Kong WY, Chen D, Wang S, Tantillo DJ. Analogies between photochemical reactions and ground-state post-transition-state bifurcations shed light on dynamical origins of selectivity. Nat Chem 2024; 16:615-623. [PMID: 38216753 DOI: 10.1038/s41557-023-01410-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 11/27/2023] [Indexed: 01/14/2024]
Abstract
Revealing the origins of kinetic selectivity is one of the premier tasks of applied theoretical organic chemistry, and for many reactions, doing so involves comparing competing transition states. For some reactions, however, a single transition state leads directly to multiple products, in which case non-statistical dynamic effects influence selectivity control. The selectivity of photochemical reactions-where crossing between excited-state and ground-state surfaces occurs near ground-state transition structures that interconvert competing products-also should be controlled by the momentum of the reacting molecules as they return to the ground state in addition to the shape of the potential energy surfaces involved. Now, using machine-learning-assisted non-adiabatic molecular dynamics and multiconfiguration pair-density functional theory, these factors are examined for a classic photochemical reaction-the deazetization of 2,3-diazabicyclo[2.2.2]oct-2-ene-for which we demonstrate that momentum dominates the selectivity for hexadiene versus [2.2.2] bicyclohexane products.
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Affiliation(s)
- Zhitao Feng
- Department of Chemistry, University of California, Davis, Davis, CA, USA
| | - Wentao Guo
- Department of Chemistry, University of California, Davis, Davis, CA, USA
| | - Wang-Yeuk Kong
- Department of Chemistry, University of California, Davis, Davis, CA, USA
| | - Dongjie Chen
- Department of Electrical and Computer Engineering, University of California, Davis, Davis, CA, USA
| | - Shunyang Wang
- Department of Chemistry, University of California, Davis, Davis, CA, USA
| | - Dean J Tantillo
- Department of Chemistry, University of California, Davis, Davis, CA, 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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He TB, Yan BC, Zhou YF, Sang YQ, Li XN, Sun HD, Wang C, Xue XS, Puno PT. Discovery and bioinspired total syntheses of unprecedented sesquiterpenoid dimers unveiled bifurcating [4 + 2] cycloaddition and target differentiation of enantiomers. Chem Sci 2024; 15:1260-1270. [PMID: 38274075 PMCID: PMC10806648 DOI: 10.1039/d3sc05233h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/27/2023] [Indexed: 01/27/2024] Open
Abstract
[4 + 2] cycloaddition has led to diverse polycyclic chiral architectures, serving as novel sources for organic synthesis and biological exploration. Here, an unprecedented class of cadinane sesquiterpene [4 + 2] dimers, henryinins A-E (1-5), with a unique 6/6/6/6/6-fused pentacyclic system, were isolated from Schisandra henryi. The divergent total syntheses of compounds 1-5 and their enantiomers (6-10) were concisely accomplished in eight linear steps using a protection-free approach. Mechanistic studies illustrated the origin of selectivity in the key [4 + 2] cycloaddition as well as the inhibition of reaction pathway bifurcation via desymmetrization. The chemical proteomics results showed that a pair of enantiomers shared common targets (PRDX5 C100 and BLMH C73) and had unique targets (USP45 C588 for 4 and COG7 C419 for 9). This work provides experimental evidence for the discovery of unprecedented cadinane dimers from selective Diels-Alder reaction and a powerful strategy to explore the biological properties of natural products.
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Affiliation(s)
- Tao-Bin He
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201 China
| | - Bing-Chao Yan
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201 China
| | - Yuan-Fei Zhou
- Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 China
| | - Yue-Qian Sang
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences Shanghai200032 China
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201 China
| | - Han-Dong Sun
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201 China
| | - Chu Wang
- Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 China
| | - Xiao-Song Xue
- Key Laboratory of Organofluorine Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences Shanghai200032 China
| | - Pema-Tenzin Puno
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Yunnan Key Laboratory of Natural Medicinal Chemistry Kunming 650201 China
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6
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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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7
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Kosteczka GL, Soek RN, Richter WE, Campos RB. Substituent effects on intramolecular Schmidt reactions: a theoretical study on the formation of bridged lactams. Org Biomol Chem 2023; 21:4114-4122. [PMID: 37129005 DOI: 10.1039/d3ob00532a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The competitive formation of isomeric bridged lactams via acid-catalyzed intramolecular Schmidt reactions from 3-azidoethylcyclopentanones is explored using density functional theory (DFT) calculations, primarily performed at the M06-2X/6-311++G(d,p) level of theory. The results indicate that specific substituents installed at α-carbons can efficiently control the regioselectivity of the reaction by lone pair-cation interactions or steric hindrance reversing the main product preference, whereas cation-π interactions are not so effective.
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Affiliation(s)
- Guilherme L Kosteczka
- Universidade Tecnológica Federal do Paraná, Rua Deputado Heitor de Alencar Furtado, 5000, 81280-340, Curitiba, PR, Brazil.
| | - Rafael N Soek
- Universidade Tecnológica Federal do Paraná, Rua Deputado Heitor de Alencar Furtado, 5000, 81280-340, Curitiba, PR, Brazil.
| | - Wagner E Richter
- Universidade Tecnológica Federal do Paraná, Rua Deputado Heitor de Alencar Furtado, 5000, 81280-340, Curitiba, PR, Brazil.
| | - Renan B Campos
- Universidade Tecnológica Federal do Paraná, Rua Deputado Heitor de Alencar Furtado, 5000, 81280-340, Curitiba, PR, Brazil.
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8
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Guo W, Hare SR, Chen SS, Saunders CM, Tantillo DJ. C-H Insertion in Dirhodium Tetracarboxylate-Catalyzed Reactions despite Dynamical Tendencies toward Fragmentation: Implications for Reaction Efficiency and Catalyst Design. J Am Chem Soc 2022; 144:17219-17231. [PMID: 36098581 DOI: 10.1021/jacs.2c07681] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rh-catalyzed C-H insertion reactions to form β-lactones suffer from post-transition state bifurcations, with the same transition states leading to ketones and ketenes via fragmentation in addition to β-lactones. In such a circumstance, traditional transition state theory cannot predict product selectivity, so we employed ab initio molecular dynamics simulations to do so and provide a framework for rationalizing the origins of said selectivity. Weak interactions between the catalyst and substrate were studied using energy decomposition and noncovalent interaction analyses, which unmasked an important role of the 2-bromophenyl substituent that has been used in multiple β-lactone-forming C-H insertion reactions. Small and large catalysts were shown to behave differently, with the latter providing a means of overcoming dynamically preferred fragmentation by lowering the barrier for the recombination of the product fragments in the grip of the large catalyst active site cavity.
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Affiliation(s)
- Wentao Guo
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Stephanie R Hare
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Shu-Sen Chen
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Carla M Saunders
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California, Davis, California 95616, United States
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9
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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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10
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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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11
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Tremblay MT, Yang ZJ. The effect of zero‐point energy in simulating organic reactions with post‐transition state bifurcation. J PHYS ORG CHEM 2022. [DOI: 10.1002/poc.4322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Zhongyue J. Yang
- Department of Chemistry Vanderbilt University Nashville Tennessee USA
- Center for Structural Biology Vanderbilt University Nashville Tennessee USA
- Vanderbilt Institute of Chemical Biology Vanderbilt University Nashville Tennessee USA
- Data Science Institute Vanderbilt University Nashville Tennessee USA
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12
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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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13
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Wang X, Zhang C, Jiang Y, Wang W, Zhou Y, Chen Y, Zhang B, Tan RX, Ge HM, Yang ZJ, Liang Y. Influence of Water and Enzyme on the Post-Transition State Bifurcation of NgnD-Catalyzed Ambimodal [6+4]/[4+2] Cycloaddition. J Am Chem Soc 2021; 143:21003-21009. [PMID: 34851644 DOI: 10.1021/jacs.1c10760] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The enzyme NgnD catalyzes an ambimodal cycloaddition that bifurcates to [6+4]- and [4+2]-adducts. Both products have been isolated in experiments, but it remains unknown how enzyme and water influence the bifurcation selectivity at the femtosecond time scale. Here, we study the impact of water and enzyme on the post-transition state bifurcation of NgnD-catalyzed [6+4]/[4+2] cycloaddition by integrating quantum mechanics/molecular mechanics quasiclassical dynamics simulations and biochemical assays. The ratio of [6+4]/[4+2] products significantly differs in the gas phase, water, and enzyme. Biochemical assays were employed to validate computational predictions. The study informs how water and enzyme affect the bifurcation selectivity through perturbation of the reaction dynamics in the femtosecond time scale, revealing the fundamental roles of condensed media in dynamically controlling the chemical selectivity for biosynthetic reactions.
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Affiliation(s)
- Xin Wang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.,Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Chun Zhang
- School of Pharmaceutical Sciences, Jiangnan University, Wuxi 214122, China
| | - Yaoyukun Jiang
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Wen Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Institute of Functional Biomolecules, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Yuan Zhou
- Henan-Macquarie University Joint Centre for Biomedical Innovation, School of Life Sciences, Henan University, Kaifeng, Henan 475004, China
| | - Yu Chen
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Bo Zhang
- State Key Laboratory of Pharmaceutical Biotechnology, Institute of Functional Biomolecules, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Ren Xiang Tan
- State Key Laboratory of Pharmaceutical Biotechnology, Institute of Functional Biomolecules, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Hui Ming Ge
- State Key Laboratory of Pharmaceutical Biotechnology, Institute of Functional Biomolecules, Chemistry and Biomedicine Innovation Center, School of Life Sciences, Nanjing University, Nanjing 210023, China
| | - Zhongyue J Yang
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, United States.,Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee 37235, United States.,Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235, United States.,Data Science Institute, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Yong Liang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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14
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Ebisawa S, Hasebe M, Tsutsumi T, Tsuneda T, Taketsugu T. Natural reaction orbitals for characterizing electron transfer responsive to nuclear coordinate displacement. Phys Chem Chem Phys 2021; 24:3532-3545. [PMID: 34780590 DOI: 10.1039/d1cp04491e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The natural reaction orbital (NRO) is proposed as a new concept for analyzing chemical reactions from the viewpoint of the electronic theory. The pair of the occupied and virtual NROs that characterize electron transfer responsive to nuclear coordinate displacement along the reaction path is automatically extracted from the solution of the coupled-perturbed self-consistent-field (CPSCF) equation for the perturbation of the nuclear displacement. The NRO-based reaction analysis method is applied to several reactions. As a result, it is found that the sum of squares of the singular values, derived from the solution of the CPSCF equation, gives sharp peaks around the transition state structures and at the shoulders of the potential energy curve. The peaks around the transition states suggest a new physical meaning of transition state from the viewpoint of the electronic theory. Furthermore, the double peaks reveal the asynchronous processes of reactions, which are not always shown in potential energy analyses. Since the NRO-based reaction analysis method is universal and robust for describing reaction mechanisms from an electronic theory viewpoint, it is expected to lead to universal reaction analyses based on the electronic theory.
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Affiliation(s)
- Shuichi Ebisawa
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Masatoshi Hasebe
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Takuro Tsutsumi
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
| | - Takao Tsuneda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan. .,Graduate School of Science Technology and Innovation, Kobe University, Nada-ku, Kobe, Hyogo 657-8501, 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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15
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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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16
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Xu T, Nie X, Li S, Yang Y, Früchtl H, van Mourik T, Kirk SR, Paterson MJ, Shigeta Y, Jenkins S. Chirality without Stereoisomers: Insight from the Helical Response of Bond Electrons. Chemphyschem 2021; 22:1989-1995. [PMID: 34269504 DOI: 10.1002/cphc.202100397] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 07/14/2021] [Indexed: 11/05/2022]
Abstract
The association between molecular chirality and helical characteristics known as the chirality-helicity equivalence is determined for the first time by quantifying a chirality-helicity measure consistent with photoexcitation circular dichroism experiments. This is demonstrated using a formally achiral SN 2 reaction and a chiral SN 2 reaction. Both the achiral and chiral SN 2 reactions possess significant values of the chirality-helicity measure and display a Walden inversion, i. e. an inversion of the chirality between the reactant and product. We also track the chirality-helicity measure along the reaction path and discover the presence of chirality at the transition state and two intermediate structures for both reactions. We demonstrate the need for the chirality-helicity measure to differentiate between steric effects due to eclipsed conformations and chiral behaviors in formally achiral species. We explain the significance of this work for asymmetric synthetic reactions including the intermediate structures where the Cahn-Ingold-Prelog (CIP) rules cannot be used.
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Affiliation(s)
- Tianlv Xu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource, National and Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Xing Nie
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource, National and Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Shuman Li
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource, National and Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Yong Yang
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource, National and Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Herbert Früchtl
- EaStCHEM School of Chemistry, University of Saint Andrews, North Haugh, St Andrews, Fife, KY16 9ST, Scotland, United Kingdom
| | - Tanja van Mourik
- EaStCHEM School of Chemistry, University of Saint Andrews, North Haugh, St Andrews, Fife, KY16 9ST, Scotland, United Kingdom
| | - Steven R Kirk
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource, National and Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China
| | - Martin J Paterson
- Institute of Chemical Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK
| | - Yasuteru Shigeta
- Center for Computational Sciences, University of Tsukuba, Tsukuba, 305-8577, Japan
| | - Samantha Jenkins
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research and Key Laboratory of Resource, National and Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan, 410081, China
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17
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Kpante M, Wolf LM. Pathway Bifurcations in the Activation of Allylic Halides by Palladium and Their Influence on the Dynamics of η 1 and η 3 Allyl Intermediates. J Org Chem 2021; 86:9637-9650. [PMID: 34190566 DOI: 10.1021/acs.joc.1c00891] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Transition-metal-catalyzed allylic substitution often exhibits complex product selectivity patterns, which have been primarily attributed to π ↔ σ ↔ π isomerization of the η1 and η3 allyl intermediates. Product selectivity may be even further complicated if η1- and η3-allyls share a single transition state (TS), leading to their formation resulting in a post-transition-state bifurcation (PTSB). In this work, density functional theory calculations using ab initio molecular dynamics (AIMD) have been carried out that support the presence of a PTSB in Pd-catalyzed allylic halide activation directly influencing product selectivity. The AIMD results initiated from the TS predict the η1-allyl to be favored in the gas phase and a low dielectric (ε < 2.5) for trialkylphosphines, while the selectivity shifts toward the η3-allyl in higher dielectrics. The minimum energy path is also predicted to shift in product preference, consistent with the dynamics predictions. The bifurcation in allylic chloride activation is predicted to largely favor the η3-allyl at any solvent polarity. A PTSB was also discovered to be present in Ni and Pt allylic activation but with less bifurcation. These results offer a unique view into the mechanism of metal-catalyzed allylic substitution.
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Affiliation(s)
- Malkaye Kpante
- Department of Chemistry, Kennedy College of Sciences, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Lawrence M Wolf
- Department of Chemistry, Kennedy College of Sciences, University of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
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18
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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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19
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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: 15] [Impact Index Per Article: 5.0] [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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20
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Vinogradov MM, Nesterov ID, Nelyubina YV, Pavlov AA. Pathway bifurcations in the cage rearrangement of metallacarboranes: experimental and computational evidence. Dalton Trans 2021; 50:287-293. [PMID: 33300519 DOI: 10.1039/d0dt03538f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Thirteen new metallacarborane complexes of rhodium and iridium with covalently bound cage carbon atoms were synthesized and their thermal stability was investigated. Two iridium complexes undergo a polyhedral rearrangement with the formation of more than one isomer. The structures of the new isomers were determined by a single crystal X-ray diffraction analysis and 11B{1H}-11B{1H} COSY NMR. A full isomerization scheme of the less thermally stable complex was proposed based on DFT calculations. According to this mechanism sequential downhill and uphill bifurcations arise in the reaction pathway. Each bifurcation is responsible for a new product formation.
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Affiliation(s)
- Mikhail M Vinogradov
- A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova str. 28, Moscow 119991, Russian Federation.
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21
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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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22
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García-Garrido V, Katsanikas M, Agaoglou M, Wiggins S. Tuning the branching ratio in a symmetric potential energy surface with a post-transition state bifurcation using external time dependence. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137714] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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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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24
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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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25
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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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26
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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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27
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Burns JM, Boittier ED. Pathway Bifurcation in the (4 + 3)/(5 + 2)-Cycloaddition of Butadiene and Oxidopyrylium Ylides: The Significance of Molecular Orbital Isosymmetry. J Org Chem 2019; 84:5997-6005. [DOI: 10.1021/acs.joc.8b03236] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Jed M. Burns
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4067 Queensland, Australia
| | - Eric D. Boittier
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, 4067 Queensland, Australia
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