1
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Ma P, Svatunek D, Zhu Z, Boger DL, Duan XH, Houk KN. Computational Studies of Reactions of 1,2,4,5-Tetrazines with Enamines in MeOH and HFIP. J Am Chem Soc 2024; 146:18706-18713. [PMID: 38941192 DOI: 10.1021/jacs.4c06067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/30/2024]
Abstract
The reaction between 1,2,4,5-tetrazines and alkenes in polar solvents proceeds through a Diels-Alder cycloaddition along the C-C axis (C3/C6 cycloaddition) of the tetrazine, followed by dinitrogen loss. By contrast, the reactions of 1,2,4,5-tetrazines with enamines in hexafluoroisopropanol (HFIP) give 1,2,4-triazine products stemming from a formal Diels-Alder addition across the N-N axis (N1/N4 cycloaddition). We explored the mechanism of this interesting solvent effect through DFT calculations in detail and revealed a novel reaction pathway characterized by C-N bond formation, deprotonation, and a 3,3-sigmatropic rearrangement. The participation of an HFIP molecule was found to be crucial to the N1/N4 selectivity over C3/C6 due to the more favored initial C-N bond formation than C-C bond formation.
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Affiliation(s)
- Pengchen Ma
- Department of Chemistry, School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry and Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Dennis Svatunek
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
- Institute of Applied Synthetic Chemistry, TU Wien, 1060 Vienna, Austria
| | - Zixi Zhu
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Dale L Boger
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Xin-Hua Duan
- Department of Chemistry, School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry and Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
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2
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Svatunek D. Computational Organic Chemistry: The Frontier for Understanding and Designing Bioorthogonal Cycloadditions. Top Curr Chem (Cham) 2024; 382:17. [PMID: 38727989 PMCID: PMC11087259 DOI: 10.1007/s41061-024-00461-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Accepted: 04/06/2024] [Indexed: 05/13/2024]
Abstract
Computational organic chemistry has become a valuable tool in the field of bioorthogonal chemistry, offering insights and aiding in the progression of this branch of chemistry. In this review, I present an overview of computational work in this field, including an exploration of both the primary computational analysis methods used and their application in the main areas of bioorthogonal chemistry: (3 + 2) and [4 + 2] cycloadditions. In the context of (3 + 2) cycloadditions, detailed studies of electronic effects have informed the evolution of cycloalkyne/1,3-dipole cycloadditions. Through computational techniques, researchers have found ways to adjust the electronic structure via hyperconjugation to enhance reactions without compromising stability. For [4 + 2] cycloadditions, methods such as distortion/interaction analysis and energy decomposition analysis have been beneficial, leading to the development of bioorthogonal reactants with improved reactivity and the creation of orthogonal reaction pairs. To conclude, I touch upon the emerging fields of cheminformatics and machine learning, which promise to play a role in future reaction discovery and optimization.
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Affiliation(s)
- Dennis Svatunek
- Institute of Applied Synthetic Chemistry, Technische Universität Wien (TU Wien), Getreidemarkt 9, 1060, Vienna, Austria.
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3
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Frenklach A, Amlani H, Kozuch S. Quantum Tunneling Instability in Pericyclic Reactions. J Am Chem Soc 2024; 146:11823-11834. [PMID: 38634836 DOI: 10.1021/jacs.4c00608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
Several cycloreversion reactions of the retro-Diels-Alder type were computationally assessed to understand their quantum tunneling (QT) reactivity. N2, CO, and other leaving groups were considered based on their strong exothermicity, as it reduces their thermodynamic and kinetic stabilities. Our results indicate that for many of these reactions, it is essential to take into account their QT decomposition rate, which can massively weaken their molecular stability and shorten their half-lives even at deep cryogenic temperatures. In practical terms, this indicates that many supposedly stable molecules will actually be unsynthesizable or unisolable, and therefore trying to prepare or detect them would be a futile attempt. In addition, we discuss the importance of tunneling to correctly understand the enthalpy of activation and the collective atomic effect on the tunneling kinetic isotope effects to test if third-row atoms can tunnel in a chemical reaction. This project raises the question of the importance of in silico chemistry to guide in vitro chemistry, especially in cases where the latter cannot solve its own uncertainties.
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Affiliation(s)
- Alexander Frenklach
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 841051, Israel
| | - Hila Amlani
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 841051, Israel
| | - Sebastian Kozuch
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 841051, Israel
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4
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Svatunek D, Chojnacki K, Deb T, Eckvahl H, Houk KN, Franzini RM. Orthogonal Inverse-Electron-Demand Cycloaddition Reactions Controlled by Frontier Molecular Orbital Interactions. Org Lett 2023; 25:6340-6345. [PMID: 37591496 PMCID: PMC10476241 DOI: 10.1021/acs.orglett.3c02265] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Indexed: 08/19/2023]
Abstract
Chemoselective pairs of bioorthogonal reactants enable the simultaneous labeling of several biomolecules. Here, we access orthogonal click reactions by exploiting differences in frontier molecular orbital interaction energies in transition states. We establish that five-membered cyclic dienes are inert to isonitriles but readily react with strained alkynes, while tetrazines with bulky substituents readily react with isonitriles. Strained alkynes show an opposite reactivity pattern. The approach was demonstrated by orthogonally labeling two proteins with different fluorophores.
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Affiliation(s)
- Dennis Svatunek
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, Los Angeles, California 90095, United States
- Institute
of Applied Synthetic Chemistry, TU Wien, 1060 Vienna, Austria
| | - Konrad Chojnacki
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Titas Deb
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
| | - Hannah Eckvahl
- 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
| | - Raphael M. Franzini
- Department
of Medicinal Chemistry, University of Utah, Salt Lake City, Utah 84112, United States
- Huntsman
Cancer Institute, Salt Lake City, Utah 84112, United States
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5
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Rodríguez H, Cruz DA, Padrón JI, Fernández I. Lewis Acid-Catalyzed Carbonyl-Ene Reaction: Interplay between Aromaticity, Synchronicity, and Pauli Repulsion. J Org Chem 2023; 88:11102-11110. [PMID: 37485981 PMCID: PMC10407925 DOI: 10.1021/acs.joc.3c01059] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Indexed: 07/25/2023]
Abstract
The physical factors governing the catalysis in Lewis acid-promoted carbonyl-ene reactions have been explored in detail quantum chemically. It is found that the binding of a Lewis acid to the carbonyl group directly involved in the transformation greatly accelerates the reaction by decreasing the corresponding activation barrier up to 25 kcal/mol. The Lewis acid makes the process much more asynchronous and the corresponding transition state less in-plane aromatic. The remarkable acceleration induced by the catalyst is ascribed, by means of the activation strain model and the energy decomposition analysis methods, mainly to a significant reduction of the Pauli repulsion between the key occupied π-molecular orbitals of the reactants and not to the widely accepted stabilization of the LUMO of the enophile.
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Affiliation(s)
- Humberto
A. Rodríguez
- Instituto
de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas (IPNA-CSIC), Avda. Astrofísico Francisco
Sánchez 3, 38206 La Laguna, Tenerife, Islas Canarias, Spain
- Departamento
de Química Orgánica I and Centro de Innovación
en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Daniel A. Cruz
- Instituto
de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas (IPNA-CSIC), Avda. Astrofísico Francisco
Sánchez 3, 38206 La Laguna, Tenerife, Islas Canarias, Spain
| | - Juan I. Padrón
- Instituto
de Productos Naturales y Agrobiología, Consejo Superior de Investigaciones Científicas (IPNA-CSIC), Avda. Astrofísico Francisco
Sánchez 3, 38206 La Laguna, Tenerife, Islas Canarias, Spain
| | - Israel Fernández
- Departamento
de Química Orgánica I and Centro de Innovación
en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
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6
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Houszka N, Mikula H, Svatunek D. Substituent Effects in Bioorthogonal Diels-Alder Reactions of 1,2,4,5-Tetrazines. Chemistry 2023; 29:e202300345. [PMID: 36853623 PMCID: PMC10946812 DOI: 10.1002/chem.202300345] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/01/2023]
Abstract
1,2,4,5-Tetrazines are increasingly used as reactants in bioorthogonal chemistry due to their high reactivity in Diels-Alder reactions with various dienophiles. Substituents in the 3- and 6-positions of the tetrazine scaffold are known to have a significant impact on the rate of cycloadditions; this is commonly explained on the basis of frontier molecular orbital theory. In contrast, we show that reactivity differences between commonly used classes of tetrazines are not controlled by frontier molecular orbital interactions. In particular, we demonstrate that mono-substituted tetrazines show high reactivity due to decreased Pauli repulsion, which leads to a more asynchronous approach associated with reduced distortion energy. This follows the recent Vermeeren-Hamlin-Bickelhaupt model of reactivity increase in asymmetric Diels-Alder reactions. In addition, we reveal that ethylene is not a good model compound for other alkenes in Diels-Alder reactions.
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Affiliation(s)
- Nicole Houszka
- Institute of Applied Synthetic ChemistryTU WienGetreidemarkt 91060ViennaAustria
| | - Hannes Mikula
- Institute of Applied Synthetic ChemistryTU WienGetreidemarkt 91060ViennaAustria
| | - Dennis Svatunek
- Institute of Applied Synthetic ChemistryTU WienGetreidemarkt 91060ViennaAustria
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7
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Zhang ZF, Su MD. Influence of Group 15 elements on the [3 + 2] cycloaddition reactivity of G15 = G15-G15-based 1,3-dipoles with cyclooctyne. Dalton Trans 2023; 52:4796-4807. [PMID: 36939158 DOI: 10.1039/d3dt00313b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
The influence of Group 15 elements (G15s) on the reactivity of the cycloaddition reactions of inorganic 1,3-dipolar analogs with cyclooctyne was computationally explored with density functional theory. To this end, the G15G15G15'-based 1,3-dipole, an interestingly representative model molecule of 1,3-dipole chemistry, was selected. The present computational investigations suggest that all NNG15-Rea and G15G15P-Rea molecules can be energetically feasible to undergo 1,3-dipolar cycloaddition reactions with cyclic alkynes, except for only the NNN-Rea 1,3-dipole molecule. The key factor, which can greatly affect the activation barriers, is quantitatively analyzed in detail through the frontier molecular orbital (FMO) theory, the activation strain model (ASM), and the energy decomposition analysis (EDA) approach. Our theoretical findings based on the FMO theory and the EDA suggest that two types of bonding interactions occur in such 1,3-dipolar cycloaddition reactions: forward bonding (filled p-π orbital (cyclooctyne) → the empty p-π* orbital (G15 = G15)) and back bonding (empty p-π* orbital (cyclooctyne) ← the lone pair (G15')). Notably, the bonding interactions of the former mechanism are much stronger than those of the latter mechanism. Evidence from the ASM reveals that the activation barriers of G15G15G15'-based 1,3-dipolar cycloaddition reactions strongly depend on the atomic radius of the G15 element. These theoretical conclusions allow a number of predictions to be made.
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Affiliation(s)
- Zheng-Feng Zhang
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan.
| | - Ming-Der Su
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan. .,Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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8
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Sengupta A, Li B, Svatunek D, Liu F, Houk KN. Cycloaddition Reactivities Analyzed by Energy Decomposition Analyses and the Frontier Molecular Orbital Model. Acc Chem Res 2022; 55:2467-2479. [PMID: 36007242 DOI: 10.1021/acs.accounts.2c00343] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This Account describes our quest to understand and predict organic reactivity, a principal goal of physical and theoretical organic chemistry. The focus is on the development and testing of models for the prediction of cycloaddition reactivities and selectivities. We describe the involvement of the Houk group, and other groups, in the evolution of theoretical models that can achieve ever greater accuracy as well as provide practical heuristic models for understanding and prediction.Is the venerable frontier molecular orbital (FMO) model, the basis of Kenichi Fukui's 1981 Nobel Prize, still useful, or must it be replaced with more advanced models? In particular, models such as Conceptual Density Functional, the Pauli Exclusion Model, and the recent popularity of Electrostatic Potential Plots and Dispersion Energies have not only added to our understanding, but they have also created uncertainty about whether the simple FMO heuristic model has a place in 21st century discussions. This Account addresses this issue and asserts the value of the FMO model.Beginning with brief descriptions of selected models for cycloaddition reactivity starting with early donor-acceptor (nucleophile-electrophile) charge-transfer concepts, this Account reviews Fukui's frontier molecular orbital model, Salem and Klopman's orbital, electrostatic and Pauli repulsion model, the conceptual DFT model by Parr and later by Domingo and others, the recent Houk and Bickelhaupt Distortion/Interaction Activation Strain model, and the Bickelhaupt-Hamlin's Pauli-repulsion lowering model.Computations and analyses of four well-studied Diels-Alder cycloadditions, both normal and inverse electron-demand types, are presented. Most were studied earlier in our published work but are presented here with new insights from calculations with modern methods. Depending on the types of substrates (cycloaddends), the dominant factors controlling reactivity can be orbital interactions, electrostatics and polarization, or Pauli repulsion and dispersion effects, or a combination of all of these.By comparing orbital interactions, especially the frontier molecular orbital interactions, with the other factors that influence reactivity, we show why the FMO model is such a powerful─and theoretically meaningful─heuristic for understanding and predicting reactivity. We also present a method to understand Pauli repulsion effects on activation barriers, ρ(1.1). The use of a new reaction coordinate, the extent of Pauli repulsion along the reaction path, is advocated to emphasize the role of repulsive occupied orbital interactions on reactivity.Fukui's frontier molecular orbital model is effective because FMO interactions parallel all the quantities that influence reactivity. The FMO model continues to provide a practical model to understand and guide experiments.
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Affiliation(s)
- Arkajyoti Sengupta
- Department of Chemistry and Biochemistry, University of California, Los Angeles 90095, California, United States
| | - Bo Li
- Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China
| | - Dennis Svatunek
- Department of Chemistry and Biochemistry, University of California, Los Angeles 90095, California, United States
| | - Fang Liu
- College of Sciences, Nanjing Agricultural University, Nanjing 210024, Jiangsu, China
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles 90095, California, United States
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9
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Wu ZC, Houk KN, Boger DL, Svatunek D. Mechanistic Insights into the Reaction of Amidines with 1,2,3-Triazines and 1,2,3,5-Tetrazines. J Am Chem Soc 2022; 144:10921-10928. [PMID: 35666564 PMCID: PMC9228069 DOI: 10.1021/jacs.2c03726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
1,2,3-Triazines and 1,2,3,5-tetrazines react rapidly, efficiently, and selectively with amidines to form pyrimidines/1,3,5-triazines, exhibiting an orthogonal reactivity with 1,2,4,5-tetrazine-based conjugation chemistry. Whereas the mechanism of the reaction of the isomeric 1,2,4-triazines and 1,2,4,5-tetrazines with alkenes is well understood, the mechanism of the 1,2,3-triazine/1,2,3,5-tetrazine-amidine reaction as well as its intrinsic reactivity remains underexplored. By using 15N-labeling, kinetic investigations, and kinetic isotope effect studies, complemented by extensive computational investigations, we show that this reaction proceeds through an addition/N2 elimination/cyclization pathway, rather than the generally expected concerted or stepwise Diels-Alder/retro Diels-Alder sequence. The rate-limiting step in this transformation is the initial nucleophilic attack of an amidine on azine C4, with a subsequent energetically favored N2 elimination step compared with a disfavored stepwise formation of a Diels-Alder cycloadduct. The proposed reaction mechanism is in agreement with experimental and computational results, which explains the observed reactivity of 1,2,3-triazines and 1,2,3,5-tetrazines with amidines.
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Affiliation(s)
- Zhi-Chen Wu
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States
| | - Dale L Boger
- Department of Chemistry, The Scripps Research Institute, La Jolla, California 92037, United States.,Department of Chemistry, The Skaggs Institute for Chemical Biology, La Jolla, California 92037, United States
| | - Dennis Svatunek
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095, United States.,Institute of Applied Synthetic Chemistry, TU Wien, 1060 Vienna, Austria
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10
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Li TL, Lu WC. Energy decomposition analysis of cationic carbene analogues with groups 13 and 16 elements as a central atom: A comparative study. Phys Chem Chem Phys 2022; 24:8970-8978. [DOI: 10.1039/d1cp05884c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Decomposition of the molecular interaction energies into physically intuitive components provides insights to the chemical bonding between fragments. The extended transition state-natural orbital for chemical valence (ETS-NOCV) and natural energy...
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11
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Lu Y, Tantillo DJ. Comparison of (5 + 2) Cycloadditions Involving Oxidopyrylium and Oxidopyridinium Ions: Relative Reactivities. J Org Chem 2021; 86:8652-8659. [PMID: 34111355 DOI: 10.1021/acs.joc.1c00396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A variety of (5 + 2) cycloaddition reactions involving oxidopyridinium and oxidopyrylium zwitterions are compared to investigate the effects of nitrogen-for-oxygen substitution on reactivity. Activation barriers for nitrogen-containing systems are predicted to be larger than those for analogous oxygen-containing systems. Correlations between barrier heights and synchronicity of C-C bond formation, changes to aromaticity, reactant distortion, and interaction energies between zwitterions and alkenes were assessed, leading to the conclusion that reactivity depends more on distortion effects (including aromaticity loss) than on interaction effects (such as those associated with highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) interactions).
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Affiliation(s)
- Yining Lu
- 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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12
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Hashikawa Y, Li H, Murata Y. Reactions of C 60 with Pyridazine and Phthalazine. Chemistry 2021; 27:7507-7511. [PMID: 33797148 DOI: 10.1002/chem.202100711] [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: 02/26/2021] [Indexed: 01/14/2023]
Abstract
Cage-opened bisfulleroids are one of suitable building blocks for making a large hole on fullerenes. This work focuses on the Diels-Alder reaction of C60 with azines, among synthetic methods developed thus far, to provide bisfulleroids. Surprisingly, the computational study predicted that the reaction proceeds with normal electron demand in contrast to hitherto considered inverse-electron-demand pathway. The benzoannulation to the pyridazine ring, i. e., phthalazine, resulted in the remarkably shortened reaction time due to the better interaction between the HOMO of phthalazine and the LUMO of C60 as well as stronger 2,3-diaza-1,3-butadiene character in the phthalazine as confirmed crystallographically. Contrary to expectations, the benzobisfulleroid was converted into corresponding orifice-enlarged derivative via the photooxygenation slightly faster than the fulleroid derived from pyridazine.
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Affiliation(s)
- Yoshifumi Hashikawa
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Hui Li
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Yasujiro Murata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
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13
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Yu S, Vermeeren P, Hamlin TA, Bickelhaupt FM. How Oriented External Electric Fields Modulate Reactivity. Chemistry 2021; 27:5683-5693. [PMID: 33289179 PMCID: PMC8049047 DOI: 10.1002/chem.202004906] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/04/2020] [Indexed: 01/27/2023]
Abstract
A judiciously oriented external electric field (OEEF) can catalyze a wide range of reactions and can even induce endo/exo stereoselectivity of cycloaddition reactions. The Diels-Alder reaction between cyclopentadiene and maleic anhydride is studied by using quantitative activation strain and Kohn-Sham molecular orbital theory to pinpoint the origin of these catalytic and stereoselective effects. Our quantitative model reveals that an OEEF along the reaction axis induces an enhanced electrostatic and orbital interaction between the reactants, which in turn lowers the reaction barrier. The stronger electrostatic interaction originates from an increased electron density difference between the reactants at the reactive center, and the enhanced orbital interaction arises from the promoted normal electron demand donor-acceptor interaction driven by the OEEF. An OEEF perpendicular to the plane of the reaction axis solely stabilizes the exo pathway of this reaction, whereas the endo pathway remains unaltered and efficiently steers the endo/exo stereoselectivity. The influence of the OEEF on the inverse electron demand Diels-Alder reaction is also investigated; unexpectedly, it inhibits the reaction, as the electric field now suppresses the critical inverse electron demand donor-acceptor interaction.
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Affiliation(s)
- Song Yu
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - Pascal Vermeeren
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - F. Matthias Bickelhaupt
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
- Institute for Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
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14
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Li TL, Zhang ZF, Su MD. Reactivity of dicationic N-heterocyclic chalcogen carbene analogues with methane and ethene: a theoretical investigation. Phys Chem Chem Phys 2021; 23:2419-2429. [PMID: 33459738 DOI: 10.1039/d0cp06173e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of chalcogen N-heterocyclic carbenic (NHC) dications [(Dipp2DAB)M2+, M = O, S, Se, and Te, and Dipp2DAB = 1,4-(2,6-diisopropyl)phenyl-1,4-diaza-1,3-butadiene] with methane and ethene are investigated by the density functional theory. The activation energies and reaction enthalpies are analyzed by the energy decomposition analysis (EDA) to understand the reactivity of the reactions. Calculations show that the oxide carbenic dication (Dipp2DAB)O2+ reactant has a pair of rather unbalanced O-N bonds due to the combined effects of the smallness of the central O atom and the bulkiness of the two Dipp ligands surrounding the DAB ring, suggesting the oxide reactant is much less stable than the chalcogenide ones. Because of its unique characteristics, the oxide carbenic dication distinguishes itself from the rest of the chalcogen family. The differences between oxides and chalcogenides of the chalcogen family complexes well known in inorganic chemistry are also observed in this theoretical investigation. This work further reveals that the reasons for the distinctive characteristics between oxide and chalcogenide complexes are due to the fundamental fact that the 2s and 2p atomic orbitals are more amenable to hybridization than those of higher valences, and the mixing of the former valence orbitals results in much smaller atoms than the latter.
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Affiliation(s)
- Tsung-Lung Li
- Department of Electrophysics, National Chia-Yi University, Chiayi 60004, Taiwan.
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15
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Deb T, Tu J, Franzini RM. Mechanisms and Substituent Effects of Metal-Free Bioorthogonal Reactions. Chem Rev 2021; 121:6850-6914. [DOI: 10.1021/acs.chemrev.0c01013] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Titas Deb
- Department of Medicinal Chemistry, University of Utah, 30 S 2000 E, Salt Lake City, Utah 84112, United States
| | - Julian Tu
- Department of Medicinal Chemistry, University of Utah, 30 S 2000 E, Salt Lake City, Utah 84112, United States
| | - Raphael M. Franzini
- Department of Medicinal Chemistry, University of Utah, 30 S 2000 E, Salt Lake City, Utah 84112, United States
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16
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Domingo LR, Pérez P. Lithium Cation-Catalyzed Benzene Diels-Alder Reaction: Insights on the Molecular Mechanism Within the Molecular Electron Density Theory. J Org Chem 2020; 85:13121-13132. [PMID: 32870671 DOI: 10.1021/acs.joc.0c01801] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The lithium cation Li+-catalyzed Diels-Alder (DA) reactions of benzene toward a series of acetylenes of improved nucleophilicity can be described within the context of the molecular electron density theory (MEDT) at the ωB97XD/6-311G(d,p) level. Conceptual density functional theory indices characterize the crown ether solvated complex benzene-lithium Bz-Li-Cro as a superelectrophile. Coordination of a lithium cation to benzene does not change substantially the electron localization function electronic structure of benzene. The DA reaction of Bz-Li-Cro with acetylene shows a reduction of the energy of activation of 6.9 kcal·mol-1, which is not sufficient for the reaction to take place, thus demanding the participation of strong nucleophilic acetylenes. DA reactions of complexes Bz-M-Cro (M = Li, Na, and K) are decelerated with the decrease of the ionization potential of the alkali metal. The one-step mechanism of these lithium cation Li+-catalyzed DA reactions changes to a two-step one for the reaction with dimethyl propynamine. The present MEDT study proves that analysis of the electrophilicity and nucleophilicity indices is an excellent tool for experimental organic chemists to understand, even to predict, the chemical organic reactivity.
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Affiliation(s)
- Luis R Domingo
- Department of Organic Chemistry, University of Valencia, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain
| | - Patricia Pérez
- Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Computational and Theoretical Chemistry Group, Universidad Andres Bello, Av. República 498, Santiago 8370146, Chile
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17
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Yu S, Vermeeren P, van Dommelen K, Bickelhaupt FM, Hamlin TA. Understanding the 1,3-Dipolar Cycloadditions of Allenes. Chemistry 2020; 26:11529-11539. [PMID: 32220086 PMCID: PMC7540365 DOI: 10.1002/chem.202000857] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/25/2020] [Indexed: 02/03/2023]
Abstract
We have quantum chemically studied the reactivity, site-, and regioselectivity of the 1,3-dipolar cycloaddition between methyl azide and various allenes, including the archetypal allene propadiene, heteroallenes, and cyclic allenes, by using density functional theory (DFT). The 1,3-dipolar cycloaddition reactivity of linear (hetero)allenes decreases as the number of heteroatoms in the allene increases, and formation of the 1,5-adduct is, in all cases, favored over the 1,4-adduct. Both effects find their origin in the strength of the primary orbital interactions. The cycloaddition reactivity of cyclic allenes was also investigated, and the increased predistortion of allenes, that results upon cyclization, leads to systematically lower activation barriers not due to the expected variations in the strain energy, but instead from the differences in the interaction energy. The geometric predistortion of cyclic allenes enhances the reactivity compared to linear allenes through a unique mechanism that involves a smaller HOMO-LUMO gap, which manifests as more stabilizing orbital interactions.
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Affiliation(s)
- Song Yu
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - Pascal Vermeeren
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - Kevin van Dommelen
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - F. Matthias Bickelhaupt
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institute for Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
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18
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Levandowski BJ, Abularrage NS, Raines RT. Differential Effects of Nitrogen Substitution in 5- and 6-Membered Aromatic Motifs. Chemistry 2020; 26:8862-8866. [PMID: 32166866 PMCID: PMC7374023 DOI: 10.1002/chem.202000825] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Indexed: 12/30/2022]
Abstract
The replacement of carbon with nitrogen can affect the aromaticity of organic rings. Nucleus-independent chemical shift (NICS) calculations at the center of the aromatic π-systems reveal that incorporating nitrogen into 5-membered heteroaromatic dienes has only a small influence on aromaticity. In contrast, each nitrogen incorporated into benzene results in a sequential and substantial loss of aromaticity. The contrasting effects of nitrogen substitution in 5-membered dienes and benzene are reflected in their Diels-Alder reactivities as dienes. 1,2-Diazine experiences a 1011 -fold increase in reactivity upon nitrogen substitution at the 4- and 5-positions, whereas a 5-membered heteroaromatic diene, furan, experiences a comparatively incidental 102 -fold increase in reactivity upon nitrogen substitution at the 3- and 4-positions.
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Affiliation(s)
- Brian J. Levandowski
- Dedicated to Rolf Huisgen in honor of his 100 birthday and contributions to cycloaddition chemistry
| | - Nile S. Abularrage
- Dedicated to Rolf Huisgen in honor of his 100 birthday and contributions to cycloaddition chemistry
| | - Ronald T. Raines
- Dedicated to Rolf Huisgen in honor of his 100 birthday and contributions to cycloaddition chemistry
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19
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Zhang ZF, Li TL, Su MD. Understanding the reactivity of carbene-analogous phosphane complexes with group 13 elements as a central atom: a theoretical investigation. NEW J CHEM 2020. [DOI: 10.1039/d0nj01708f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The reactions of carbenic cations (PtBu3)2M+ (M = B, Al, Ga, In, and Tl) with methane and ethene are studied using density functional theory.
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Affiliation(s)
- Zheng-Feng Zhang
- Department of Applied Chemistry
- National Chiayi University
- Chiayi 60004
- Taiwan
| | - Tsung-Lung Li
- Department of Electrophysics
- National Chia-Yi University
- Chiayi 60004
- Taiwan
| | - Ming-Der Su
- Department of Applied Chemistry
- National Chiayi University
- Chiayi 60004
- Taiwan
- Department of Medicinal and Applied Chemistry
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20
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Domingo LR, Ríos-Gutiérrez M, Pérez P. A molecular electron density theory study of the enhanced reactivity of aza aromatic compounds participating in Diels–Alder reactions. Org Biomol Chem 2020; 18:292-304. [DOI: 10.1039/c9ob02467k] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The change of C–H by N: in these aromatic compounds decreases the ring electron density (RED), thus decreasing the activation energies of the aza Diels–Alder reactions mainly by the loss of the aromatic character of the reagents.
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Affiliation(s)
- Luis R. Domingo
- Department of Organic Chemistry
- University of Valencia
- 46100 Burjassot
- Spain
| | - Mar Ríos-Gutiérrez
- Department of Organic Chemistry
- University of Valencia
- 46100 Burjassot
- Spain
- Department of Chemistry and Chemical Biology
| | - Patricia Pérez
- Universidad Andres Bello
- Facultad de Ciencias Exactas
- Departamento de Ciencias Químicas
- Computational and Theoretical Chemistry Group
- 8370146 Santiago
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21
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Narsaria AK, Hamlin TA, Lammertsma K, Bickelhaupt FM. Dual Activation of Aromatic Diels-Alder Reactions. Chemistry 2019; 25:9902-9912. [PMID: 31111976 PMCID: PMC6771859 DOI: 10.1002/chem.201901617] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/20/2019] [Indexed: 11/20/2022]
Abstract
The unusually fast Diels-Alder reactions of [5]cyclophanes were analyzed by DFT at the BLYP-D3(BJ)/TZ2P level of theory. The computations were guided by an integrated activation-strain and Kohn-Sham molecular orbital analysis. It is revealed why both [5]metacyclophane and [5]paracyclophane exhibit a significant rate enhancement compared to their planar benzene analogue. The activation strain analyses revealed that the enhanced reactivity originates from 1) predistortion of the aromatic core resulting in a reduced activation strain of the aromatic diene, and/or 2) enhanced interaction with the dienophile through a distortion-controlled lowering of the HOMO-LUMO gap within the diene. Both of these physical mechanisms and thus the rate of Diels-Alder cycloaddition can be tuned through different modes of geometrical distortion (meta versus para bridging) and by heteroatom substitution in the aromatic ring. Judicious choice of the bridge and heteroatom in the aromatic core enables effective tuning of the aromatic Diels-Alder reactivity to achieve activation barriers as low as 2 kcal mol-1 , which is an impressive 35 kcal mol-1 lower than that of benzene.
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Affiliation(s)
- Ayush K. Narsaria
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
| | - Koop Lammertsma
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
- Department of ChemistryUniversity of JohannesburgAuckland ParkJohannesburg2006South Africa
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081HVAmsterdamThe Netherlands
- Institute for Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525AJNijmegenThe Netherlands
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22
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Li X, Duan R, Wang Y, Qu LB, Li Z, Wei D. Insights into N-Heterocyclic Carbene-Catalyzed Oxidative α-C(sp 3)-H Activation of Aliphatic Aldehydes and Cascade [2 + 2] Cycloaddition with Ketimines. J Org Chem 2019; 84:6117-6125. [PMID: 31012584 DOI: 10.1021/acs.joc.9b00295] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Predicting the chemoselectivity of [2 + 2] cyclizations is an important challenge in organic chemistry. Herein, we provided a valuable case for this issue. Density functional theory calculations were performed to systematically study the possible mechanisms and origin of selectivities for the N-heterocyclic carbene (NHC)-catalyzed oxidative α-C(sp3)-H activation of aliphatic aldehydes and the cascade [2 + 2] cycloaddition with ketimines. The [2 + 2] cycloaddition of azolium enolate intermediates to the C═N bond, rather than the C═O bond of ketimine, is revealed to be determined by chemo- and stereoselectivity. By comparing the energy gap between the frontier molecular orbitals (FMOs) of the two reacting parts involved in the [2 + 2] cycloaddition transition states, we propose a new strategy to determine the origin of the reaction chemoselectivity. Moreover, the local nucleophilic index can efficiently predict the active site of ketimines. Further analyses illustrate that NHC can increase the nucleophilicity of aldehydes and the acidity of the α-C(sp3)-H bond, and 3,3',5,5'-tetra- tert-butyl diphenoquinone (DQ) acts as an oxidant and promotes α-C(sp3)-H bond deprotonation. This work is useful not only for understanding the NHC-catalyzed oxidative [2 + 2] annulation but also for developing new applications of the FMO theory in organocatalytic cyclizations.
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Affiliation(s)
- Xue Li
- The College of Chemistry and Molecular Engineering , Zhengzhou University , 100 Science Avenue , Zhengzhou , Henan 450001 , P. R. China
| | - Ruihong Duan
- The College of Chemistry and Molecular Engineering , Zhengzhou University , 100 Science Avenue , Zhengzhou , Henan 450001 , P. R. China
| | - Yanyan Wang
- The College of Chemistry and Molecular Engineering , Zhengzhou University , 100 Science Avenue , Zhengzhou , Henan 450001 , P. R. China
| | - Ling-Bo Qu
- The College of Chemistry and Molecular Engineering , Zhengzhou University , 100 Science Avenue , Zhengzhou , Henan 450001 , P. R. China
| | - Zhongjun Li
- The College of Chemistry and Molecular Engineering , Zhengzhou University , 100 Science Avenue , Zhengzhou , Henan 450001 , P. R. China
| | - Donghui Wei
- The College of Chemistry and Molecular Engineering , Zhengzhou University , 100 Science Avenue , Zhengzhou , Henan 450001 , P. R. China
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23
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Cabrera-Trujillo JJ, Fernández I. Understanding exo-selective Diels-Alder reactions involving Fischer-type carbene complexes. Org Biomol Chem 2019; 17:2985-2991. [PMID: 30810152 DOI: 10.1039/c9ob00132h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The factors controlling the selectivity of the Diels-Alder cycloaddition reactions involving Fischer-type carbene complexes and cyclopentadiene have been explored computationally by means of density functional theory calculations. To this end, the influence of the substituents directly attached to the carbene ligand on the endo : exo ratio has been compared to the available experimental data and quantitatively analysed in detail by means of the combination of the activation strain model of reactivity and energy decomposition analysis methods. The insight gained in this computational study may be important for the rational design of exo-selective Diels-Alder reactions.
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Affiliation(s)
- Jorge Juan Cabrera-Trujillo
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040-Madrid, Spain.
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24
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Shi Q, Wang W, Wang Y, Lan Y, Yao C, Wei D. Prediction on the origin of chemoselectivity in Lewis base-mediated competition cyclizations between allenoates and chalcones: a computational study. Org Chem Front 2019. [DOI: 10.1039/c9qo00606k] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The HOMOTSs and p-orbital contributions of the center atoms were used to predict the origin of chemoselectivity in this work.
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Affiliation(s)
- Qianqian Shi
- College of Chemistry and Molecular Engineering
- and School of Basic Medical Sciences
- Zhengzhou University
- Zhengzhou
- P. R. China
| | - Wei Wang
- College of Chemistry and Molecular Engineering
- and School of Basic Medical Sciences
- Zhengzhou University
- Zhengzhou
- P. R. China
| | - Yang Wang
- Department of Material and Chemical Engineering
- Zhengzhou University of Light Industry
- Zhengzhou
- P. R. China
| | - Yu Lan
- College of Chemistry and Molecular Engineering
- and School of Basic Medical Sciences
- Zhengzhou University
- Zhengzhou
- P. R. China
| | - Changsheng Yao
- Jiangsu Key Lab of Green Synthetic Chemistry for Functional Materials
- School of Chemistry & Materials Science
- Jiangsu Normal University
- Xuzhou
- P. R. China
| | - Donghui Wei
- College of Chemistry and Molecular Engineering
- and School of Basic Medical Sciences
- Zhengzhou University
- Zhengzhou
- P. R. China
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25
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Yu JL, Zhang SQ, Hong X. Stepwise versus Concerted Reductive Elimination Mechanisms in the Carbon–Iodide Bond Formation of (DPEphos)RhMeI2 Complex. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00723] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jing-Lu Yu
- Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Shuo-Qing Zhang
- Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Xin Hong
- Department of Chemistry, Zhejiang University, Hangzhou 310027, People’s Republic of China
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26
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Yu S, de Bruijn HM, Svatunek D, Hamlin TA, Bickelhaupt FM. Factors Controlling the Diels-Alder Reactivity of Hetero-1,3-Butadienes. ChemistryOpen 2018; 7:995-1004. [PMID: 30524925 PMCID: PMC6276106 DOI: 10.1002/open.201800193] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Indexed: 12/29/2022] Open
Abstract
We have quantum chemically explored the Diels-Alder reactivities of a systematic series of hetero-1,3-butadienes with ethylene by using density functional theory at the BP86/TZ2P level. Activation strain analyses provided physical insight into the factors controlling the relative cycloaddition reactivity of aza- and oxa-1,3-butadienes. We find that dienes with a terminal heteroatom, such as 2-propen-1-imine (NCCC) or acrolein (OCCC), are less reactive than the archetypal 1,3-butadiene (CCCC), primarily owing to weaker orbital interactions between the more electronegative heteroatoms with ethylene. Thus, the addition of a second heteroatom at the other terminal position (NCCN and OCCO) further reduces the reactivity. However, the introduction of a nitrogen atom in the backbone (CNCC) leads to enhanced reactivity, owing to less Pauli repulsion resulting from polarization of the diene HOMO in CNCC towards the nitrogen atom and away from the terminal carbon atom. The Diels-Alder reactions of ethenyl-diazene (NNCC) and 1,3-diaza-butadiene (NCNC), which contain heteroatoms at both the terminal and backbone positions, are much more reactive due to less activation strain compared to CCCC.
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Affiliation(s)
- Song Yu
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Hans M de Bruijn
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Leiden Institute of Chemistry, Gorlaeus Laboratories Leiden University P.O. Box 9502 2300 RA Leiden The Netherlands
| | - Dennis Svatunek
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Institut für Angewandte Synthesechemie Technische Universität Wien (TU Wien) Getreidemarkt 9 1060 Vienna Austria
| | - Trevor A Hamlin
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - F Matthias Bickelhaupt
- Department of Theoretical Chemistry, Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Institute for Molecules and Materials (IMM) Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
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27
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García-Rodeja Y, Solà M, Fernández I. Influence of the charge on the reactivity of azafullerenes. Phys Chem Chem Phys 2018; 20:28011-28018. [PMID: 30382266 DOI: 10.1039/c8cp06031b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The influence of the charge on the Diels-Alder reactivity of azafullerenes (C59N+ and C59N-) has been computationally explored by means of density functional theory calculations. In addition, the regioselectivity of the process has been investigated and compared to the analogous cycloaddition reaction involving the parent neutral azahydro[60]fullerene C59NH. It is found that the [4+2]-cycloaddition reaction between C59N+ and cyclopentadiene, which occurs concertedly through a synchronous transition state, proceeds with a lower activation barrier and is more exothermic than the analogous process involving C59NH. In contrast, the anionic C59N- counterpart is clearly less reactive. This reactivity trend is quantitatively analyzed in detail by means of the activation strain model of reactivity in combination with the energy decomposition analysis method. It is found that the frontier molecular orbital interactions are not responsible for the observed reactivity trend but the Pauli repulsion between closed-shells mainly governs the transformation.
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Affiliation(s)
- Yago García-Rodeja
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040-Madrid, Spain.
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28
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Śniechowska J, Paluch P, Pawlak T, Bujacz GD, Danikiewicz W, Potrzebowski MJ. New synthetic pathway leading to oxospirochlorins. RSC Adv 2018; 8:21354-21362. [PMID: 35539919 PMCID: PMC9080854 DOI: 10.1039/c8ra02445f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/04/2018] [Indexed: 11/21/2022] Open
Abstract
In this work we propose a completely new approach for the synthesis of spirochlorin derivatives based on the use of an imino-keto intermediate formed in situ from 2-amino-5,10,15,20-tetraphenylporphyrins and inverse electron demand Diels-Alder (iEDDA) cycloaddition with 3,6-di-2-pyridyl-1,2,4,5-tetrazine. The mechanism of reaction was analyzed employing theoretical methods by comparing the difference in energy of Frontier Molecular Orbitals (FMO) for appropriate reagents. Ground-state molecular electrostatic (ESP) potential maps were employed as additional tools allowing explanation of the reactivity of substrates. The new class of spirochlorin compounds was fully characterized by means of mass spectrometry, IR, liquid and solid state NMR and X-ray crystallography. Correlation between molecular structure and optical properties for the obtained title compounds is discussed.
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Affiliation(s)
- Justyna Śniechowska
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences Sienkiewicza 112 90-363 Lodz Poland
| | - Piotr Paluch
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences Sienkiewicza 112 90-363 Lodz Poland
| | - Tomasz Pawlak
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences Sienkiewicza 112 90-363 Lodz Poland
| | - Grzegorz D Bujacz
- Institute of Technical Biochemistry, Lodz University of Technology Stefanowskiego 4/10 90-924 Lodz Poland
| | - Witold Danikiewicz
- Institute of Organic Chemistry, Polish Academy of Sciences Kasprzaka 44/52 01-224 Warsaw Poland
| | - Marek J Potrzebowski
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences Sienkiewicza 112 90-363 Lodz Poland
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29
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Breugst M, Huisgen R, Reissig HU. Regioselective 1,3-Dipolar Cycloadditions of Diazoalkanes with Heteroatom-Substituted Alkynes: Theory and Experiment. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800100] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Martin Breugst
- Department für Chemie; Universität zu Köln; Greinstr. 4 50939 Köln Germany
| | - Rolf Huisgen
- Department Chemie; Ludwig-Maximilians-Universität München; Butenandtstraße 5-13 (Haus F) 81377 München Germany
| | - Hans-Ulrich Reissig
- Institut für Chemie und Biochemie; Freie Universität Berlin; Takustr. 3 14195 Berlin Germany
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30
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Yang YF, Yu P, Houk KN. Computational Exploration of Concerted and Zwitterionic Mechanisms of Diels-Alder Reactions between 1,2,3-Triazines and Enamines and Acceleration by Hydrogen-Bonding Solvents. J Am Chem Soc 2017; 139:18213-18221. [PMID: 29161031 PMCID: PMC6314813 DOI: 10.1021/jacs.7b08325] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The mechanisms of Diels-Alder reactions between 1,2,3-triazines and enamines have been explored with density functional theory computations. The focus of this work is on the origins of the different reactivities and mechanisms induced by substituents and by hexafluoroisopropanol (HFIP) solvent. These inverse electron-demand Diels-Alder reactions of triazines have wide applications in bioorthogonal chemistry and natural product synthesis. Both concerted and stepwise cycloadditions are predicted, depending on the nature of substituents and solvents. The nature of zwitterionic intermediates and the mechanism by which HFIP accelerates cycloadditions with enamines are characterized. Our results show the delicate nature of the concerted versus stepwise mechanism of inverse electron-demand Diels-Alder reactions of 1,2,3-triazines, and that these mechanisms can be altered by electron-withdrawing substituents and hydrogen-bonding solvents.
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Affiliation(s)
- Yun-Fang Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Peiyuan Yu
- 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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31
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Duret G, Le Fouler V, Bisseret P, Bizet V, Blanchard N. Diels-Alder and Formal Diels-Alder Cycloaddition Reactions of Ynamines and Ynamides. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700986] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Guillaume Duret
- CNRS, LCM UMR 7509; Université de Strasbourg; 67000 Strasbourg France
| | - Vincent Le Fouler
- CNRS, LCM UMR 7509; Université de Strasbourg; 67000 Strasbourg France
| | - Philippe Bisseret
- CNRS, LCM UMR 7509; Université de Strasbourg; 67000 Strasbourg France
| | - Vincent Bizet
- CNRS, LCM UMR 7509; Université de Strasbourg; 67000 Strasbourg France
| | - Nicolas Blanchard
- CNRS, LCM UMR 7509; Université de Strasbourg; 67000 Strasbourg France
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32
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García-Rodeja Y, Solà M, Bickelhaupt FM, Fernández I. Understanding the Reactivity of Ion-Encapsulated Fullerenes. Chemistry 2017; 23:11030-11036. [DOI: 10.1002/chem.201701506] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Indexed: 11/05/2022]
Affiliation(s)
- Yago García-Rodeja
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi and Departament de Química; Universitat de Girona; C/ Maria Aurèlia Campany 69 17003 Girona Spain
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM); Vrije Universiteit Amsterdam; De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Institute for Molecules and Materials (IMM); Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Israel Fernández
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas; Universidad Complutense de Madrid; 28040 Madrid Spain
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33
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Liu Y, Guo X, Tang D, Wang J, Wu P, Han J, Chen B. Synthesis of 1,2,4-Triazine Compounds via Two Distinct One-Pot Domino Protocols. CHINESE J CHEM 2017. [DOI: 10.1002/cjoc.201600922] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Yafeng Liu
- State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou Gansu 730000 China
| | - Xin Guo
- State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou Gansu 730000 China
| | - Dong Tang
- Department of Chemistry; Lishui University; Lishui Zhejiang 323000 China
| | - Jing Wang
- State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou Gansu 730000 China
| | - Ping Wu
- State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou Gansu 730000 China
| | - Jianwei Han
- State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou Gansu 730000 China
| | - Baohua Chen
- State Key Laboratory of Applied Organic Chemistry; Lanzhou University; Lanzhou Gansu 730000 China
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34
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Duret G, Quinlan R, Yin B, Martin RE, Bisseret P, Neuburger M, Gandon V, Blanchard N. Intramolecular Inverse Electron-Demand [4 + 2] Cycloadditions of Ynamides with Pyrimidines: Scope and Density Functional Theory Insights. J Org Chem 2017; 82:1726-1742. [PMID: 28059511 DOI: 10.1021/acs.joc.6b02986] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
4-Aminopyridines are valuable scaffolds for the chemical industry in general, from life sciences to catalysis. We report herein a collection of structurally diverse polycyclic fused and spiro-4-aminopyridines that are prepared in only three steps from commercially available pyrimidines. The key step of this short sequence is a [4 + 2]/retro-[4 + 2] cycloaddition between a pyrimidine and an ynamide, which constitutes the first examples of ynamides behaving as electron-rich dienophiles in [4 + 2] cycloaddition reactions. In addition, running the ihDA/rDA reaction in continuous mode in superheated toluene, to overcome the limited scalability of MW reactions, results in a notable production increase compared to batch mode. Finally, density functional theory investigations shed light on the energetic and geometric requirements of the different steps of the ihDA/rDA sequence.
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Affiliation(s)
- Guillaume Duret
- Laboratoire de Chimie Moléculaire UMR 7509, Université de Strasbourg, CNRS , Strasbourg F-67000, France
| | - Robert Quinlan
- Laboratoire de Chimie Moléculaire UMR 7509, Université de Strasbourg, CNRS , Strasbourg F-67000, France
| | - Boyang Yin
- Laboratoire de Chimie Moléculaire UMR 7509, Université de Strasbourg, CNRS , Strasbourg F-67000, France
| | - Rainer E Martin
- Medicinal Chemistry, Roche Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche, Ltd. , Grenzacherstrasse 124, Basel CH-4070, Switzerland
| | - Philippe Bisseret
- Laboratoire de Chimie Moléculaire UMR 7509, Université de Strasbourg, CNRS , Strasbourg F-67000, France
| | - Markus Neuburger
- Department of Chemistry, University of Basel , Spitalstrasse 51, Basel CH-4056, Switzerland
| | - Vincent Gandon
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS UMR 8182, Université Paris-Sud, Université Paris-Saclay , bâtiment 420, Orsay cedex 91405, France.,Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Université Paris-Sud, Université Paris-Saclay , 1 av. de la Terrasse, Gif-sur-Yvette 91198, France
| | - Nicolas Blanchard
- Laboratoire de Chimie Moléculaire UMR 7509, Université de Strasbourg, CNRS , Strasbourg F-67000, France
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35
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Fernández I, Bickelhaupt FM. Deeper Insight into the Diels-Alder Reaction through the Activation Strain Model. Chem Asian J 2016; 11:3297-3304. [DOI: 10.1002/asia.201601203] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Israel Fernández
- Departamento de Química Orgánica I; Universidad Complutense de Madrid; Ciudad Universitaria 28040- Madrid Spain
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling (ACMM); Vrije Universiteit Amsterdam; De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Institute of Molecules and Materials; Radboud University; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
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36
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Zhou Q, Fursule I, Berron BJ, Beck MJ. Toward Spatiotemporally Controlled Synthesis of Photoresponsive Polymers: Computational Design of Azobenzene-Containing Monomers for Light-Mediated ROMP. J Phys Chem A 2016; 120:7101-11. [DOI: 10.1021/acs.jpca.6b05807] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qunfei Zhou
- Department of Chemical and Materials Engineering and ‡Center for Computational
Sciences, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Ishan Fursule
- Department of Chemical and Materials Engineering and ‡Center for Computational
Sciences, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Brad J. Berron
- Department of Chemical and Materials Engineering and ‡Center for Computational
Sciences, University of Kentucky, Lexington, Kentucky 40506, United States
| | - Matthew J. Beck
- Department of Chemical and Materials Engineering and ‡Center for Computational
Sciences, University of Kentucky, Lexington, Kentucky 40506, United States
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37
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Ghadari R. In silico study to evaluate the governing criteria in the BF3 catalyzed Diels-Alder reaction. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2016.07.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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38
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Duret G, Quinlan R, Martin RE, Bisseret P, Neuburger M, Gandon V, Blanchard N. Inverse Electron-Demand [4 + 2]-Cycloadditions of Ynamides: Access to Novel Pyridine Scaffolds. Org Lett 2016; 18:1610-3. [PMID: 26998920 DOI: 10.1021/acs.orglett.6b00464] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Functionalized polycyclic aminopyridines are central to the chemical sciences, but their syntheses are still hampered by a number of shortcomings. These nitrogenated heterocycles can be efficiently prepared by an intramolecular inverse electron demand hetero Diels-Alder (ihDA) cycloaddition of ynamides to pyrimidines. This ihDA/rDA sequence is general in scope and affords expedient access to novel types of aminopyridinyl scaffolds that hold great promise in terms of exit vector patterns.
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Affiliation(s)
- Guillaume Duret
- Laboratoire de Chimie Moléculaire, Université de Strasbourg , CNRS UMR 7509, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Robert Quinlan
- Laboratoire de Chimie Moléculaire, Université de Strasbourg , CNRS UMR 7509, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Rainer E Martin
- Medicinal Chemistry, Roche Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd. , Grenzacherstrasse 124, CH-4070 Basel, Switzerland
| | - Philippe Bisseret
- Laboratoire de Chimie Moléculaire, Université de Strasbourg , CNRS UMR 7509, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
| | - Markus Neuburger
- Department of Chemistry, University of Basel , Spitalstrasse 51, CH-4056 Basel, Switzerland
| | - Vincent Gandon
- Institut de Chimie Moléculaire et des Matériaux d'Orsay, CNRS UMR 8182, Université. Paris-Sud, Université Paris-Saclay , bâtiment 420, 91405 Orsay cedex, France.,Institut de Chimie des Substances Naturelles, CNRS UPR 2301, Univ. Paris-Sud, Université Paris-Saclay , 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Nicolas Blanchard
- Laboratoire de Chimie Moléculaire, Université de Strasbourg , CNRS UMR 7509, ECPM, 25 rue Becquerel, 67087 Strasbourg, France
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39
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Yang YF, Liang Y, Liu F, Houk KN. Diels-Alder Reactivities of Benzene, Pyridine, and Di-, Tri-, and Tetrazines: The Roles of Geometrical Distortions and Orbital Interactions. J Am Chem Soc 2016; 138:1660-7. [PMID: 26804318 DOI: 10.1021/jacs.5b12054] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The cycloadditions of benzene and ten different azabenzenes (pyridine, three diazines, three triazines, and three tetrazines) with the ethylene dienophile have been explored with density functional theory (M06-2X) and analyzed with the distortion/interaction model. Activation barriers correlate closely with both distortion energies and interaction energies over an activation energy range of 45 kcal/mol. The replacement of CH with N increases Diels-Alder reactivity due not only to the more favorable orbital interaction, but also to a decrease in distortion energy. The rates of reactions are greatly influenced by the nature of the bonds being formed: two C-C bonds > one C-C bond, and one C-N bond > two C-N bonds. The activation energy of Diels-Alder reactions correlates very well with reaction energies and with the NICS(0) values of the aromatic dienes. The distortion energy of the Diels-Alder reaction transition states mostly arises from the diene out-of-plane distortion energy.
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Affiliation(s)
- Yun-Fang Yang
- Department of Chemistry and Biochemistry, ‡Department of Chemical and Biomolecular Engineering, University of California , Los Angeles, California 90095, United States
| | - Yong Liang
- Department of Chemistry and Biochemistry, ‡Department of Chemical and Biomolecular Engineering, University of California , Los Angeles, California 90095, United States
| | - Fang Liu
- Department of Chemistry and Biochemistry, ‡Department of Chemical and Biomolecular Engineering, University of California , Los Angeles, California 90095, United States
| | - K N Houk
- Department of Chemistry and Biochemistry, ‡Department of Chemical and Biomolecular Engineering, University of California , Los Angeles, California 90095, United States
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40
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García-Rodeja Y, Solà M, Bickelhaupt FM, Fernández I. Reactivity and Selectivity of Bowl-Shaped Polycyclic Aromatic Hydrocarbons: Relationship to C60. Chemistry 2015; 22:1368-78. [DOI: 10.1002/chem.201502248] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Indexed: 11/05/2022]
Affiliation(s)
- Yago García-Rodeja
- Departamento de Química Orgánica; Facultad de Química; Universidad Complutense; 28040 Madrid Spain), Fax: (+34)913944310
| | - Miquel Solà
- Institut de Química Computacional and Departament de Química; Universitat de Girona, Campus Montilivi; 17071 Girona Spain
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry and Amsterdam; Center for Multiscale Modeling (ACMM); VU University; De Boelelaan 1083 1081 HV Amsterdam The Netherlands
- Institute for Molecules and Materials (IMM); Radboud University Nijmegen; Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
| | - Israel Fernández
- Departamento de Química Orgánica; Facultad de Química; Universidad Complutense; 28040 Madrid Spain), Fax: (+34)913944310
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41
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Wu D, Ganguly R, Li Y, Hoo SN, Hirao H, Kinjo R. Reversible [4 + 2] cycloaddition reaction of 1,3,2,5-diazadiborinine with ethylene. Chem Sci 2015; 6:7150-7155. [PMID: 29861951 PMCID: PMC5952552 DOI: 10.1039/c5sc03174e] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/14/2015] [Indexed: 01/06/2023] Open
Abstract
Under ambient conditions, a [4 + 2] cycloaddition reaction of 1,3,2,5-diazadiborinine 1 with ethylene afforded a bicyclo[2.2.2] derivative 2, which was structurally characterized.
Under ambient conditions, a [4 + 2] cycloaddition reaction of 1,3,2,5-diazadiborinine 1 with ethylene afforded a bicyclo[2.2.2] derivative 2, which was structurally characterized. The cyclization process was found to be reversible, and thus retro-[4 + 2] cycloaddition reproduced 1 quantitatively, concomitant with the release of ethylene. Compound 1 reacted regio-selectively and stereo-selectively with styrene derivatives and norbornene, respectively, and these processes were found to be reversible too. Computational studies determined the reaction pathways which were consistent with the regio-selectivity observed in the reaction of styrene, and the reaction was suggested to be essentially concerted but highly asynchronous.
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Affiliation(s)
- Di Wu
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
| | - Rakesh Ganguly
- NTU-CBC Crystallography Facility , Nanyang Technological University , Singapore 637371 , Singapore
| | - Yongxin Li
- NTU-CBC Crystallography Facility , Nanyang Technological University , Singapore 637371 , Singapore
| | - Sin Ni Hoo
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
| | - Hajime Hirao
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
| | - Rei Kinjo
- Division of Chemistry and Biological Chemistry , School of Physical and Mathematical Sciences , Nanyang Technological University , Singapore 637371 , Singapore . ;
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42
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Wagner JA, Mercadante D, Nikić I, Lemke EA, Gräter F. Origin of Orthogonality of Strain-Promoted Click Reactions. Chemistry 2015; 21:12431-5. [PMID: 26178299 PMCID: PMC4600239 DOI: 10.1002/chem.201501727] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Indexed: 12/31/2022]
Abstract
Site-specific labeling of biomolecules is rapidly advancing due to the discovery of novel mutually orthogonal reactions. Quantum chemistry studies have also increased our understanding of their relative rates, although these have until now been based on highly simplified reactants. Here we examine a set of strain-promoted click-type cycloaddition reactions of n-propyl azide, 3-benzyl tetrazine and 3-benzyl-6-methyl tetrazine with cyclooctenes/ynes, in which we aim to address all relevant structural details of the reactants. Our calculations have included the obligatory handles used to attach the label and biomolecule as these can critically influence the stereochemistry and electron demand of the reaction. We systematically computed orbital gaps, activation and distortion energies using density functional theory and determined experimental rates for validation. Our results challenge the current paradigm of the inverse electron demand for this class of reactions. We found that the ubiquitous handles, when next to the triple bond of cyclooctynes, can switch the Diels-Alder type ligations to normal electron demand, a class we term as SPINEDAC reactions. Electron donating substituents on tetrazine can enhance normal demand but also increase distortion penalties. The presence and isomeric configuration of handles thus determine the reaction speed and regioselectivity. Our findings can be directly utilized in engineering genuine cycloaddition click chemistries for biological labeling.
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Affiliation(s)
- Johannes A Wagner
- Heidelberg Institute for Theoretical Studies69118 Heidelberg (Germany), Fax: (+49) 6221-533-298 E-mail:
- Institute for Theoretical Physics, Heidelberg University69120 Heidelberg (Germany)
| | - Davide Mercadante
- Heidelberg Institute for Theoretical Studies69118 Heidelberg (Germany), Fax: (+49) 6221-533-298 E-mail:
- Interdisciplinary Center for Scientific Computing69120 Heidelberg (Germany)
| | - Ivana Nikić
- European Molecular Biology Laboratory69117 Heidelberg (Germany)
| | - Edward A Lemke
- European Molecular Biology Laboratory69117 Heidelberg (Germany)
| | - Frauke Gräter
- Heidelberg Institute for Theoretical Studies69118 Heidelberg (Germany), Fax: (+49) 6221-533-298 E-mail:
- Interdisciplinary Center for Scientific Computing69120 Heidelberg (Germany)
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43
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Merten H, Brandl F, Plückthun A, Zangemeister-Wittke U. Antibody-Drug Conjugates for Tumor Targeting-Novel Conjugation Chemistries and the Promise of non-IgG Binding Proteins. Bioconjug Chem 2015; 26:2176-85. [PMID: 26086208 DOI: 10.1021/acs.bioconjchem.5b00260] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Antibody-drug conjugates (ADCs) have emerged as a promising class of anticancer agents, combining the specificity of antibodies for tumor targeting and the destructive potential of highly potent drugs as payload. An essential component of these immunoconjugates is a bifunctional linker capable of reacting with the antibody and the payload to assemble a functional entity. Linker design is fundamental, as it must provide high stability in the circulation to prevent premature drug release, but be capable of releasing the active drug inside the target cell upon receptor-mediated endocytosis. Although ADCs have demonstrated an increased therapeutic window, compared to conventional chemotherapy in recent clinical trials, therapeutic success rates are still far from optimal. To explore other regimes of half-life variation and drug conjugation stoichiometries, it is necessary to investigate additional binding proteins which offer access to a wide range of formats, all with molecularly defined drug conjugation. Here, we delineate recent progress with site-specific and biorthogonal conjugation chemistries, and discuss alternative, biophysically more stable protein scaffolds like Designed Ankyrin Repeat Proteins (DARPins), which may provide such additional engineering opportunities for drug conjugates with improved pharmacological performance.
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Affiliation(s)
- Hannes Merten
- Department of Biochemistry, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Fabian Brandl
- Department of Biochemistry, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.,Institute of Pharmacology, University of Bern , Inselspital INO-F, CH-3010 Bern, Switzerland
| | - Andreas Plückthun
- Department of Biochemistry, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Uwe Zangemeister-Wittke
- Department of Biochemistry, University of Zurich , Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.,Institute of Pharmacology, University of Bern , Inselspital INO-F, CH-3010 Bern, Switzerland
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44
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Yang K, Yang Z, Dang Q, Bai X. Hydrazones as Productive Dienophiles in the Inverse Electron Demand Diels-Alder Reactions of 1,3,5-Triazines. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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45
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Bickelhaupt FM, Solà M, Fernández I. Understanding the Reactivity of Endohedral Metallofullerenes: C78versus Sc3N@C78. Chemistry 2015; 21:5760-8. [DOI: 10.1002/chem.201500067] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Indexed: 11/11/2022]
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