1
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Beutick SE, Yu S, Orian L, Bickelhaupt FM, Hamlin TA. Retro-Cope elimination of cyclic alkynes: reactivity trends and rational design of next-generation bioorthogonal reagents. Chem Sci 2024:d4sc04211e. [PMID: 39239482 PMCID: PMC11369967 DOI: 10.1039/d4sc04211e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Accepted: 08/20/2024] [Indexed: 09/07/2024] Open
Abstract
The retro-Cope elimination reaction between dimethylhydroxylamine (DMHA) and various cyclic alkynes has been quantum chemically explored using DFT at ZORA-BP86/TZ2P. The purpose of this study is to understand the role of the following three unique activation modes on the overall reactivity, that is (i) additional cycloalkyne predistortion via fused cycles, (ii) exocyclic heteroatom substitution on the cycloalkyne, and (iii) endocyclic heteroatom substitution on the cycloalkyne. Trends in reactivity are analyzed and explained by using the activation strain model (ASM) of chemical reactivity. Based on our newly formulated design principles, we constructed a priori a suite of novel bioorthogonal reagents that are highly reactive towards the retro-Cope elimination reaction with DMHA. Our findings offer valuable insights into the design principles for highly reactive bioorthogonal reagents in chemical synthesis.
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Affiliation(s)
- Steven E Beutick
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam De Boelelaan 1108 Amsterdam 1081 HZ The Netherlands
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova Via Marzolo 1 Padova 35129 Italy
| | - Song Yu
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam De Boelelaan 1108 Amsterdam 1081 HZ The Netherlands
| | - Laura Orian
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova Via Marzolo 1 Padova 35129 Italy
| | - F Matthias Bickelhaupt
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam De Boelelaan 1108 Amsterdam 1081 HZ The Netherlands
- Institute of Molecules and Materials, Radboud University Heyendaalseweg 135 Nijmegen 6525 AJ The Netherlands
- Department of Chemical Sciences, University of Johannesburg Auckland Park Johannesburg 2006 South Africa
| | - Trevor A Hamlin
- Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam De Boelelaan 1108 Amsterdam 1081 HZ The Netherlands
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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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Herrmann B, Svatunek D. Directionality of Halogen-Bonds: Insights from 2D Energy Decomposition Analysis. Chem Asian J 2024:e202301106. [PMID: 38390759 DOI: 10.1002/asia.202301106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/25/2024] [Indexed: 02/24/2024]
Abstract
Halogen bonds are typically observed to have a linear arrangement with a 180° angle between the nucleophile and the halogen bond acceptor X-R. This linearity is commonly explained using the σ-hole model, although there have been alternative explanations involving exchange repulsion forces. We employ two-dimensional Distortion/Interaction and Energy Decomposition Analysis to examine the archetypal H3 N⋯X2 halogen bond systems. Our results indicate that although halogen bonds are predominantly electrostatic, their directionality is largely due to decreased Pauli repulsion in linear configurations as opposed to angled ones in the I2 and Br2 systems. As we move to the smaller halogens, Cl2 and F2 , the influence of Pauli repulsion diminishes, and the energy surface is shaped by orbital interactions and electrostatic forces. These results support the role of exchange repulsion forces in influencing the directionality of strong halogen bonds. Additionally, we demonstrate that the 2D Energy Decomposition Analysis is a useful tool for enhancing our understanding of the nature of potential energy surfaces in noncovalent interactions.
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Affiliation(s)
- Barbara Herrmann
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, 1060, Vienna, Austria
| | - Dennis Svatunek
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, 1060, Vienna, Austria
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4
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Májek M, Trtúšek M. Discovery of new tetrazines for bioorthogonal reactions with strained alkenes via computational chemistry. RSC Adv 2024; 14:4345-4351. [PMID: 38304564 PMCID: PMC10828936 DOI: 10.1039/d3ra08712c] [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: 12/21/2023] [Accepted: 01/25/2024] [Indexed: 02/03/2024] Open
Abstract
Tetrazines are widely employed reagents in bioorthogonal chemistry, as they react readily with strained alkenes in inverse electron demand Diels-Alder reactions, allowing for selective labeling of biomacromolecules. For optimal performance, tetrazine reagents have to react readily with strained alkenes, while remaining inert against nucleophiles like thiols. Balancing these conditions is a challenge, as reactivity towards strained alkenes and nucleophiles is governed by the same factor - the energy of unoccupied orbitals of tetrazine. Herein, we utilize computational chemistry to screen a set of tetrazine derivatives, aiming to identify structural elements responsible for a better ratio of reactivity with strained alkenes vs. stability against nucleophiles. This advantageous trait is present in sulfone- and sulfoxide-substituted tetrazines. In the end, the distortion/interaction model helped us to identify that the reason behind this enhanced reactivity profile is a secondary orbital interaction between the strained alkene and sulfone-/sulfoxide-substituted tetrazine. This insight can be used to design new tetrazines for bioorthogonal chemistry with improved reactivity/stability profiles.
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Affiliation(s)
- Michal Májek
- Comenius University Bratislava, Faculty of Natural Sciences, Department of Organic Chemistry Mlynská Dolina, Ilkovičova 6 842 15 Bratislava Slovakia
| | - Matej Trtúšek
- Comenius University Bratislava, Faculty of Natural Sciences, Department of Organic Chemistry Mlynská Dolina, Ilkovičova 6 842 15 Bratislava Slovakia
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5
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Fernández I, Bickelhaupt FM, Svatunek D. Unraveling the Bürgi-Dunitz Angle with Precision: The Power of a Two-Dimensional Energy Decomposition Analysis. J Chem Theory Comput 2023; 19:7300-7306. [PMID: 37791978 PMCID: PMC10601473 DOI: 10.1021/acs.jctc.3c00907] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Indexed: 10/05/2023]
Abstract
Understanding the geometrical preferences in chemical reactions is crucial for advancing the field of organic chemistry and improving synthetic strategies. One such preference, the Bürgi-Dunitz angle, is central to nucleophilic addition reactions involving carbonyl groups. This study successfully employs a novel two-dimensional Distortion-Interaction/Activation-Strain Model in combination with a two-dimensional Energy Decomposition Analysis to investigate the origins of the Bürgi-Dunitz angle in the addition reaction of CN- to (CH3)2C═O. We constructed a 2D potential energy surface defined by the distance between the nucleophile and carbonylic carbon atom and by the attack angle, followed by an in-depth exploration of energy components, including strain and interaction energy. Our analysis reveals that the Bürgi-Dunitz angle emerges from a delicate balance between two key factors: strain energy and interaction energy. High strain energy, as a result of the carbonyl compound distorting to avoid Pauli repulsion, is encountered at high angles, thus setting the upper bound. On the other hand, interaction energy is shaped by a dominant Pauli repulsion when the angles are lower. This work emphasizes the value of the 2D Energy Decomposition Analysis as a refined tool, offering both quantitative and qualitative insights into chemical reactivity and selectivity.
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Affiliation(s)
- Israel Fernández
- Departamento
de Química Orgánica and Centro de Innovación
en Química Avanzada (ORFEO−CINQA), Facultad de Ciencias
Químicas, Universidad Complutense
de Madrid, 28040-Madrid, Spain
| | - F. Matthias Bickelhaupt
- Department
of Chemistry and Pharmaceutical Sciences, AIMMS, Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
- Institute
for Molecules and Materials (IMM), Radboud
University, Nijmegen 6500 GL, The Netherlands
- Department
of Chemical Sciences, University of Johannesburg, Johannesburg 2006, South Africa
| | - Dennis Svatunek
- Institute
of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9, 1060 Vienna, Austria
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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: 7] [Impact Index Per Article: 7.0] [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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Tiekink EH, Vermeeren P, Hamlin TA. Not antiaromaticity gain, but increased asynchronicity enhances the Diels-Alder reactivity of tropone. Chem Commun (Camb) 2023; 59:3703-3706. [PMID: 36880301 DOI: 10.1039/d3cc00512g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Tropone is an unreactive diene in normal electron demand Diels-Alder reactions, but it can be activated via carbonyl umpolung by using hydrazone ion analogs. Recently, the higher reactivity of hydrazone ion analogs was ascribed to a raised HOMO energy induced by antiaromaticity (L. J. Karas, A. T. Campbell, I. V. Alabugin and J. I. Wu, Org. Lett., 2020, 22, 7083). We show that this is incorrect, and that the activation barrier is lowered by increased asynchronicity.
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Affiliation(s)
- Eveline H Tiekink
- Department of Theoretical Chemistry, Amsterdam Institute of Molecfular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, Amsterdam 1081 HV, The Netherlands.
| | - Pascal Vermeeren
- Department of Theoretical Chemistry, Amsterdam Institute of Molecfular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, Amsterdam 1081 HV, The Netherlands.
| | - Trevor A Hamlin
- Department of Theoretical Chemistry, Amsterdam Institute of Molecfular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, Amsterdam 1081 HV, The Netherlands.
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8
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Yu S, Tiekink EH, Vermeeren P, Bickelhaupt FM, Hamlin TA. How Bases Catalyze Diels-Alder Reactions. Chemistry 2023; 29:e202203121. [PMID: 36330879 PMCID: PMC10108159 DOI: 10.1002/chem.202203121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 11/06/2022]
Abstract
We have quantum chemically studied the base-catalyzed Diels-Alder (DA) reaction between 3-hydroxy-2-pyrone and N-methylmaleimide using dispersion-corrected density functional theory. The uncatalyzed reaction is slow and is preceded by the extrusion of CO2 via a retro-DA reaction. Base catalysis, for example, by triethylamine, lowers the reaction barrier up to 10 kcal mol-1 , causing the reaction to proceed smoothly at low temperature, which quenches the expulsion of CO2 , yielding efficient access to polyoxygenated natural compounds. Our activation strain analyses reveal that the base accelerates the DA reaction via two distinct electronic mechanisms: i) by the HOMO-raising effect, which enhances the normal electron demand orbital interaction; and ii) by donating charge into 3-hydroxy-2-pyrone which accumulates in its reactive region and promotes strongly stabilizing secondary electrostatic interactions with N-methylmaleimide.
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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 HVAmsterdam(TheNetherlands
| | - Eveline H. Tiekink
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdam(TheNetherlands
| | - Pascal Vermeeren
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdam(TheNetherlands
| | - 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 HVAmsterdam(TheNetherlands
- Institute for Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525 AJNijmegen (TheNetherlands
- Department of Chemical SciencesUniversity of JohannesburgAuckland ParkJohannesburg2006South Africa
| | - 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 HVAmsterdam(TheNetherlands
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9
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Beutick SE, Vermeeren P, Hamlin TA. The 1,3-Dipolar Cycloaddition: From Conception to Quantum Chemical Design. Chem Asian J 2022; 17:e202200553. [PMID: 35822651 PMCID: PMC9539489 DOI: 10.1002/asia.202200553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 07/08/2022] [Indexed: 11/12/2022]
Abstract
The 1,3-dipolar cycloaddition (1,3-DCA) reaction, conceptualized by Rolf Huisgen in 1960, has proven immensely useful in organic, material, and biological chemistry. The uncatalyzed, thermal transformation is generally sluggish and unselective, but the reactivity can be enhanced by means of metal catalysis or by the introduction of either predistortion or electronic tuning of the dipolarophile. These promoted reactions generally go with a much higher reactivity, selectivity, and yields, often at ambient temperatures. The rapid orthogonal reactivity and compatibility with aqueous and physiological conditions positions the 1,3-DCA as an excellent bioorthogonal reaction. Quantum chemical calculations have been critical for providing an understanding of the physical factors that control the reactivity and selectivity of 1,3-DCAs. In silico derived design principles have proven invaluable for the design of new dipolarophiles with tailored reactivity. This review discusses everything from the conception of the 1,3-DCA all the way to the state-of-the-art methods and models used for the quantum chemical design of novel (bioorthogonal) reagents.
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Affiliation(s)
- Steven E. Beutick
- 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
| | - 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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10
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Vermeeren P, Dalla Tiezza M, Wolf ME, Lahm ME, Allen WD, Schaefer HF, Hamlin TA, Bickelhaupt FM. Pericyclic reaction benchmarks: hierarchical computations targeting CCSDT(Q)/CBS and analysis of DFT performance. Phys Chem Chem Phys 2022; 24:18028-18042. [PMID: 35861164 PMCID: PMC9348522 DOI: 10.1039/d2cp02234f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/07/2022] [Indexed: 11/21/2022]
Abstract
Hierarchical, convergent ab initio benchmark computations were performed followed by a systematic analysis of DFT performance for five pericyclic reactions comprising Diels-Alder, 1,3-dipolar cycloaddition, electrocyclic rearrangement, sigmatropic rearrangement, and double group transfer prototypes. Focal point analyses (FPA) extrapolating to the ab initio limit were executed via explicit quantum chemical computations with electron correlation treatments through CCSDT(Q) and correlation-consistent Gaussian basis sets up to aug'-cc-pV5Z. Optimized geometric structures and vibrational frequencies of all stationary points were obtained at the CCSD(T)/cc-pVTZ level of theory. The FPA reaction barriers and energies exhibit convergence to within a few tenths of a kcal mol-1. The FPA benchmarks were used to evaluate the performance of 60 density functionals (eight dispersion-corrected), covering the local-density approximation (LDA), generalized gradient approximations (GGAs), meta-GGAs, hybrids, meta-hybrids, double-hybrids, and range-separated hybrids. The meta-hybrid M06-2X functional provided the best overall performance [mean absolute error (MAE) of 1.1 kcal mol-1] followed closely by the double-hybrids B2K-PLYP, mPW2K-PLYP, and revDSD-PBEP86 [MAE of 1.4-1.5 kcal mol-1]. The regularly used GGA functional BP86 gave a higher MAE of 5.8 kcal mol-1, but it qualitatively described the trends in reaction barriers and energies. Importantly, we established that accurate yet efficient meta-hybrid or double-hybrid DFT potential energy surfaces can be acquired based on geometries from the computationally efficient and robust BP86/DZP level.
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Affiliation(s)
- Pascal Vermeeren
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
| | - Marco Dalla Tiezza
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
| | - Mark E Wolf
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA 30602, USA.
| | - Mitchell E Lahm
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA 30602, USA.
| | - Wesley D Allen
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA 30602, USA.
- Allen Heritage Foundation, Dickson, TN 37055, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry, University of Georgia, Athens, GA 30602, USA.
| | - Trevor A Hamlin
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), 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 Institute of Molecular and Life Sciences (AIMMS), 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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11
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Abstract
The catalytic effect of ionization on the Diels-Alder reaction between 1,3-butadiene and acrylaldehyde has been studied using relativistic density functional theory (DFT). Removal of an electron from the dienophile, acrylaldehyde, significantly accelerates the Diels-Alder reaction and shifts the reaction mechanism from concerted asynchronous for the neutral Diels-Alder reaction to stepwise for the radical-cation Diels-Alder reaction. Our detailed activation strain and Kohn-Sham molecular orbital analyses reveal how ionization of the dienophile enhances the Diels-Alder reactivity via two mechanisms: (i) by amplifying the asymmetry in the dienophile's occupied π-orbitals to such an extent that the reaction goes from concerted asynchronous to stepwise and thus with substantially less steric (Pauli) repulsion per reaction step; (ii) by enhancing the stabilizing orbital interactions that result from the ability of the singly occupied molecular orbital of the radical-cation dienophile to engage in an additional three-electron bonding interaction with the highest occupied molecular orbital of the diene.
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Affiliation(s)
- Pascal Vermeeren
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical Chemistry Amsterdam 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 Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institute for Molecules and MaterialsRadboud University NijmegenHeyendaalseweg 1356525 AJNijmegenThe Netherlands
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12
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Svatunek D, Wilkovitsch M, Hartmann L, Houk KN, Mikula H. Uncovering the Key Role of Distortion in Bioorthogonal Tetrazine Tools That Defy the Reactivity/Stability Trade-Off. J Am Chem Soc 2022; 144:8171-8177. [PMID: 35500228 PMCID: PMC9100665 DOI: 10.1021/jacs.2c01056] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
![]()
The tetrazine/trans-cyclooctene ligation stands
out from the bioorthogonal toolbox due to its exceptional reaction
kinetics, enabling multiple molecular technologies in vitro and in
living systems. Highly reactive 2-pyridyl-substituted tetrazines have
become state of the art for time-critical processes and selective
reactions at very low concentrations. It is widely accepted that the
enhanced reactivity of these chemical tools is attributed to the electron-withdrawing
effect of the heteroaryl substituent. In contrast, we show that the
observed reaction rates are way too high to be explained on this basis.
Computational investigation of this phenomenon revealed that distortion
of the tetrazine caused by intramolecular repulsive N–N interaction
plays a key role in accelerating the cycloaddition step. We show that
the limited stability of tetrazines in biological media strongly correlates
with the electron-withdrawing effect of the substituent, while intramolecular
repulsion increases the reactivity without reducing the stability.
These fundamental insights reveal thus far overlooked mechanistic
aspects that govern the reactivity/stability trade-off for tetrazines
in physiologically relevant environments, thereby providing a new
strategy that may facilitate the rational design of these bioorthogonal
tools.
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Affiliation(s)
- Dennis Svatunek
- Institute of Applied Synthetic Chemistry, TU Wien 1060 Vienna, Austria
| | | | - Lea Hartmann
- Institute of Applied Synthetic Chemistry, TU Wien 1060 Vienna, Austria
| | - K N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles 90095, United States
| | - Hannes Mikula
- Institute of Applied Synthetic Chemistry, TU Wien 1060 Vienna, Austria
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13
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Li L, Mayer P, Stephenson DS, Ofial AR, Mayer RJ, Mayr H. An Overlooked Pathway in 1,3-Dipolar Cycloadditions of Diazoalkanes with Enamines. Angew Chem Int Ed Engl 2022; 61:e202117047. [PMID: 35023245 PMCID: PMC9306659 DOI: 10.1002/anie.202117047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Indexed: 11/25/2022]
Abstract
Methyl diazoacetate reacts with 1-(N-pyrrolidino)cycloalkenes to give products of 1,3-dipolar cycloadditions and azo couplings. The kinetics and mechanisms of these reactions were investigated by NMR spectroscopy and DFT calculations. Orthogonal π-systems in the 1,3-dipoles of the propargyl-allenyl type allow for two separate reaction pathways for the (3+2)-cycloadditions. The commonly considered concerted pathway is rationalized by the interaction of the enamine HOMO with LUMO+1, the lowest unoccupied orbital of the heteropropargyl anion fragment of methyl diazoacetate. We show that HOMO/LUMO(π*N=N ) interactions between enamines and methyl diazoacetate open a previously unrecognized reaction path for stepwise cycloadditions through zwitterionic intermediates with barriers approximately 40 kJ mol-1 lower in energy in CHCl3 (DFT calculations) than for the concerted path.
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Affiliation(s)
- Le Li
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–1381377MünchenGermany
| | - Peter Mayer
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–1381377MünchenGermany
| | - David S. Stephenson
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–1381377MünchenGermany
| | - Armin R. Ofial
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–1381377MünchenGermany
| | - Robert J. Mayer
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS)Université de Strasbourg & CNRS8 Allée Gaspard Monge67000StrasbourgFrance
| | - Herbert Mayr
- Department ChemieLudwig-Maximilians-Universität MünchenButenandtstraße 5–1381377MünchenGermany
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14
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Li L, Mayer P, Stephenson DS, Ofial AR, Mayer RJ, Mayr H. An Overlooked Pathway in 1,3‐Dipolar Cycloadditions of Diazoalkanes with Enamines. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202117047] [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)
- Le Li
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - Peter Mayer
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - David S. Stephenson
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - Armin R. Ofial
- Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie GERMANY
| | - Robert J. Mayer
- Université de Strasbourg: Universite de Strasbourg Institut de Science et d'Ingenierie Supramoleculaire (ISIS) FRANCE
| | - Herbert Mayr
- Ludwig-Maximilians-Universität München Fakultät für Chemie und Pharmazie: Ludwig-Maximilians-Universitat Munchen Fakultat fur Chemie und Pharmazie Dept. Chemie Butenandtstr. 5-13 81377 München GERMANY
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15
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Tiekink EH, Vermeeren P, Bickelhaupt FM, Hamlin TA. How Lewis Acids Catalyze Ene Reactions. European J Org Chem 2021. [DOI: 10.1002/ejoc.202101107] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Eveline H. Tiekink
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam, The Netherlands
| | - Pascal Vermeeren
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) 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 Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam, The Netherlands
- Institute for Molecules and Materials Radboud University Nijmegen Heyendaalseweg 135 6525 AJ Nijmegen, The Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM) Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam, The Netherlands
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16
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Vermeeren P, Hamlin TA, Bickelhaupt FM. Origin of asynchronicity in Diels-Alder reactions. Phys Chem Chem Phys 2021; 23:20095-20106. [PMID: 34499069 PMCID: PMC8457343 DOI: 10.1039/d1cp02456f] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 09/02/2021] [Indexed: 02/02/2023]
Abstract
Asynchronicity in Diels-Alder reactions plays a crucial role in determining the height of the reaction barrier. Currently, the origin of asynchronicity is ascribed to the stronger orbital interaction between the diene and the terminal carbon of an asymmetric dienophile, which shortens the corresponding newly formed C-C bond and hence induces asynchronicity in the reaction. Here, we show, using the activation strain model and Kohn-Sham molecular orbital theory at ZORA-BP86/TZ2P, that this rationale behind asynchronicity is incorrect. We, in fact, found that following a more asynchronous reaction mode costs favorable HOMO-LUMO orbital overlap and, therefore, weakens (not strengthens) these orbital interactions. Instead, it is the Pauli repulsion that induces asynchronicity in Diels-Alder reactions. An asynchronous reaction pathway also lowers repulsive occupied-occupied orbital overlap which, therefore, reduces the unfavorable Pauli repulsion. As soon as this mechanism of reducing Pauli repulsion dominates, the reaction begins to deviate from synchronicity and adopts an asynchronous mode. The eventual degree of asynchronicity, as observed in the transition state of a Diels-Alder reaction, is ultimately achieved when the gain in stability, as a response to the reduced Pauli repulsion, balances with the loss of favorable orbital interactions.
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Affiliation(s)
- Pascal Vermeeren
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
| | - Trevor A Hamlin
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), 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 Institute of Molecular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands.
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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17
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Yu S, Bickelhaupt FM, Hamlin TA. Switch From Pauli-Lowering to LUMO-Lowering Catalysis in Brønsted Acid-Catalyzed Aza-Diels-Alder Reactions. ChemistryOpen 2021; 10:784-789. [PMID: 34351072 PMCID: PMC8340067 DOI: 10.1002/open.202100172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 07/20/2021] [Indexed: 12/16/2022] Open
Abstract
Brønsted acid-catalyzed inverse-electron demand (IED) aza-Diels-Alder reactions between 2-aza-dienes and ethylene were studied using quantum chemical calculations. The computed activation energy systematically decreases as the basic sites of the diene progressively become protonated. Our activation strain and Kohn-Sham molecular orbital analyses traced the origin of this enhanced reactivity to i) "Pauli-lowering catalysis" for mono-protonated 2-aza-dienes due to the induction of an asynchronous, but still concerted, reaction pathway that reduces the Pauli repulsion between the reactants; and ii) "LUMO-lowering catalysis" for multi-protonated 2-aza-dienes due to their highly stabilized LUMO(s) and more concerted synchronous reaction path that facilitates more efficient orbital overlaps in IED interactions. In all, we illustrate how the novel concept of "Pauli-lowering catalysis" can be overruled by the traditional concept of "LUMO-lowering catalysis" when the degree of LUMO stabilization is extreme as in the case of multi-protonated 2-aza-dienes.
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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) and
| | - 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) and
- 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) and
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18
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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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19
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Chen PP, Ma P, He X, Svatunek D, Liu F, Houk KN. Computational Exploration of Ambiphilic Reactivity of Azides and Sustmann's Paradigmatic Parabola. J Org Chem 2021; 86:5792-5804. [PMID: 33769821 PMCID: PMC8154615 DOI: 10.1021/acs.joc.1c00239] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
We
examine the theoretical underpinnings of the seminal discoveries
by Reiner Sustmann about the ambiphilic nature of Huisgen’s
phenyl azide cycloadditions. Density functional calculations with
ωB97X-D and B2PLYP-D3 reproduce the experimental data and provide
insights into ambiphilic control of reactivity. Distortion/interaction-activation
strain and energy decomposition analyses show why Sustmann’s
use of dipolarophile ionization potential is such a powerful predictor
of reactivity. We add to Sustmann’s data set several modern
distortion-accelerated dipolarophiles used in bioorthogonal chemistry
to show how these fit into the orbital energy criteria that are often
used to understand cycloaddition reactivity. We show why such a simple
indicator of reactivity is a powerful predictor of reaction rates
that are actually controlled by a combination of distortion energies,
charge transfer, closed-shell repulsion, polarization, and electrostatic
effects.
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Affiliation(s)
- Pan-Pan Chen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Pengchen Ma
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Xue He
- College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Dennis Svatunek
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
| | - Fang Liu
- College of Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Kendall N Houk
- Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, United States
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20
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Svatunek D, Hansen T, Houk KN, Hamlin TA. How the Lewis Base F - Catalyzes the 1,3-Dipolar Cycloaddition between Carbon Dioxide and Nitrilimines. J Org Chem 2021; 86:4320-4325. [PMID: 33577314 PMCID: PMC8023701 DOI: 10.1021/acs.joc.0c02963] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Indexed: 12/11/2022]
Abstract
The mechanism of the Lewis base F- catalyzed 1,3-dipolar cycloaddition between CO2 and nitrilimines is interrogated using DFT calculations. F- activates the nitrilimine, not CO2 as proposed in the literature, and imparts a significant rate enhancement for the cycloaddition. The origin of this catalysis is in the strength of the primary orbital interactions between the reactants. The Lewis base activated nitrilimine-F- has high-lying filled FMOs. The smaller FMO-LUMO gap promotes a rapid nucleophilic attack and overall cycloaddition with CO2.
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Affiliation(s)
- Dennis Svatunek
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMSS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands
- Institute
of Applied Synthetic Chemistry, TU Wien
(Vienna University of Technology), A-1060, Vienna, Austria
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, California 90095, Los Angeles, United States
| | - Thomas Hansen
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMSS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Kendall N. Houk
- Department
of Chemistry and Biochemistry, University
of California, Los Angeles, California 90095, Los Angeles, United States
| | - Trevor A. Hamlin
- Department
of Theoretical Chemistry, Amsterdam Institute of Molecular and Life
Sciences (AIMSS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands
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21
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Barrales-Martínez C, Martínez-Araya JI, Jaque P. 1,3-Dipolar Cycloadditions by a Unified Perspective Based on Conceptual and Thermodynamics Models of Chemical Reactivity. J Phys Chem A 2021; 125:801-815. [PMID: 33448854 DOI: 10.1021/acs.jpca.0c10013] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The main aim in the present report is to gain a deeper understanding of typical 1,3-dipolar cycloadditions by means of three chemical reactivity models in a unified perspective: conceptual density functional theory, distortion/interaction, and reaction force analysis. The focus is to explore the information provided by each reactivity model and how they complement or reinforce each other. Our results showed that the Bell-Evans-Polanyi (BEP) relationship is fulfilled, which is consistent with the Hammond-Leffler postulate. The electronic chemical potential based analysis classifies the reactions as HOMO-, HOMO/LUMO-, and LUMO-controlled reactions as the activation energy increases. It seems likely that HOMO-controlled reaction shifts into LUMO-controlled one as the transition state (TS) position does from early into late. Therefore, the transition from HOMO- (and early TS) into LUMO-controlled (and late TS) is paid by shifting the overall energy change into an endothermic direction, thus supporting the fulfillment of the BEP principle. While thermodynamic models unveil that the distortion or structural rearrangements mainly drive the activation barriers rather than interaction or electronic rearrangements in accord with the distortion/interaction and reaction force analysis, respectively. It is also found that both models are consistent when energy associated with structural and electronic reordering from reaction force analysis is respectively confronted with destabilizing (distortion and Pauli repulsion) and stabilizing (electrostatic and orbital interactions) contributions from the distortion/interaction model, which, on the other hand, increases as low activation barrier and high exothermicity are converted into the high barrier and low exothermicity along with the BEP relation. Finally, the reaction force constant reveals that all 1,3-dipolar cycloaddition reactions proceed by a synchronous single-step mechanism, unveiling that the degree of synchronicity is quite the same in all reactions, confirming the statement that BEP is fulfilled for similar reactions proceeding by a quite alike degree of synchronicity.
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Affiliation(s)
- César Barrales-Martínez
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, Santiago 8370146, Chile.,Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone 1007, Independencia, Santiago 8380492, Chile
| | - Jorge I Martínez-Araya
- Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andrés Bello, Av. República 275, Santiago 8370146, Chile
| | - Pablo Jaque
- Departamento de Química Orgánica y Fisicoquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Sergio Livingstone 1007, Independencia, Santiago 8380492, Chile
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22
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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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23
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Breugst M, Reissig H. The Huisgen Reaction: Milestones of the 1,3-Dipolar Cycloaddition. Angew Chem Int Ed Engl 2020; 59:12293-12307. [PMID: 32255543 PMCID: PMC7383714 DOI: 10.1002/anie.202003115] [Citation(s) in RCA: 243] [Impact Index Per Article: 60.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Indexed: 12/21/2022]
Abstract
The concept of 1,3-dipolar cycloadditions was presented by Rolf Huisgen 60 years ago. Previously unknown reactive intermediates, for example azomethine ylides, were introduced to organic chemistry and the (3+2) cycloadditions of 1,3-dipoles to multiple-bond systems (Huisgen reaction) developed into one of the most versatile synthetic methods in heterocyclic chemistry. In this Review, we present the history of this research area, highlight important older reports, and describe the evolution and further development of the concept. The most important mechanistic and synthetic results are discussed. Quantum-mechanical calculations support the concerted mechanism always favored by R. Huisgen; however, in extreme cases intermediates may be involved. The impact of 1,3-dipolar cycloadditions on the click chemistry concept of K. B. Sharpless will also be discussed.
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Affiliation(s)
- Martin Breugst
- Department für ChemieUniversität zu KölnGreinstrasse 450939KölnGermany
| | - Hans‐Ulrich Reissig
- Institut für Chemie und BiochemieFreie Universität BerlinTakustrasse 314195BerlinGermany
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24
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Vermeeren P, Hamlin TA, Fernández I, Bickelhaupt FM. Origin of rate enhancement and asynchronicity in iminium catalyzed Diels-Alder reactions. Chem Sci 2020; 11:8105-8112. [PMID: 34094173 PMCID: PMC8163289 DOI: 10.1039/d0sc02901g] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/08/2020] [Indexed: 12/16/2022] Open
Abstract
The Diels-Alder reactions between cyclopentadiene and various α,β-unsaturated aldehyde, imine, and iminium dienophiles were quantum chemically studied using a combined density functional theory and coupled-cluster theory approach. Simple iminium catalysts accelerate the Diels-Alder reactions by lowering the reaction barrier up to 20 kcal mol-1 compared to the parent aldehyde and imine reactions. Our detailed activation strain and Kohn-Sham molecular orbital analyses reveal that the iminium catalysts enhance the reactivity by reducing the steric (Pauli) repulsion between the diene and dienophile, which originates from both a more asynchronous reaction mode and a more significant polarization of the π-system away from the incoming diene compared to aldehyde and imine analogs. Notably, we establish that the driving force behind the asynchronicity of the herein studied Diels-Alder reactions is the relief of destabilizing steric (Pauli) repulsion and not the orbital interaction between the terminal carbon of the dienophile and the diene, which is the widely accepted rationale.
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Affiliation(s)
- Pascal Vermeeren
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Trevor A Hamlin
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Amsterdam Center for Multiscale Modeling (ACMM), Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Israel Fernández
- Departamento de Química Orgánica I, Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de Ciencias Químicas, Universidad Complutense de Madrid 28040 Madrid Spain
| | - F Matthias Bickelhaupt
- Department of Theoretical Chemistry, Amsterdam Institute of Molecular and Life Sciences (AIMMS), 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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25
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Breugst M, Reißig H. Die Huisgen‐Reaktion: Meilensteine der 1,3‐dipolaren Cycloaddition. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003115] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Martin Breugst
- Department für Chemie Universität zu Köln Greinstraße 4 50939 Köln Deutschland
| | - Hans‐Ulrich Reißig
- Institut für Chemie und Biochemie Freie Universität Berlin Takustr. 3 14195 Berlin Deutschland
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26
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Vermeeren P, Hamlin TA, Fernández I, Bickelhaupt FM. How Lewis Acids Catalyze Diels-Alder Reactions. Angew Chem Int Ed Engl 2020; 59:6201-6206. [PMID: 31944503 PMCID: PMC7187354 DOI: 10.1002/anie.201914582] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/04/2020] [Indexed: 11/23/2022]
Abstract
The Lewis acid(LA)-catalyzed Diels-Alder reaction between isoprene and methyl acrylate was investigated quantum chemically using a combined density functional theory and coupled-cluster theory approach. Computed activation energies systematically decrease as the strength of the LA increases along the series I2
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Affiliation(s)
- 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
| | - Israel Fernández
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA)Facultad de Ciencias QuímicasUniversidad Complutense de Madrid28040MadridSpain
| | - 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 1356525AJNijmegenThe Netherlands
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Vermeeren P, Brinkhuis F, Hamlin TA, Bickelhaupt FM. How Alkali Cations Catalyze Aromatic Diels-Alder Reactions. Chem Asian J 2020; 15:1167-1174. [PMID: 32012430 PMCID: PMC7187256 DOI: 10.1002/asia.202000009] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 01/24/2020] [Indexed: 12/04/2022]
Abstract
We have quantum chemically studied alkali cation-catalyzed aromatic Diels-Alder reactions between benzene and acetylene forming barrelene using relativistic, dispersion-corrected density functional theory. The alkali cation-catalyzed aromatic Diels-Alder reactions are accelerated by up to 5 orders of magnitude relative to the uncatalyzed reaction and the reaction barrier increases along the series Li+ < Na+ < K+ < Rb+ < Cs+ < none. Our detailed activation strain and molecular-orbital bonding analyses reveal that the alkali cations lower the aromatic Diels-Alder reaction barrier by reducing the Pauli repulsion between the closed-shell filled orbitals of the dienophile and the aromatic diene. We argue that such Pauli mechanism behind Lewis-acid catalysis is a more general phenomenon. Also, our results may be of direct importance for a more complete understanding of the network of competing mechanisms towards the formation of polycyclic aromatic hydrocarbons (PAHs) in an astrochemical context.
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Affiliation(s)
- Pascal Vermeeren
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdam (TheNetherlands
| | - Francine Brinkhuis
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdam (TheNetherlands
| | - Trevor A. Hamlin
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdam (TheNetherlands
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry Amsterdam Institute of Molecular and Life Sciences (AIMMS) Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdam (TheNetherlands
- Institute for Molecules and MaterialsRadboud University NijmegenHeyendaalseweg 1356525 AJNijmegen (TheNetherlands
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Vermeeren P, Hamlin TA, Fernández I, Bickelhaupt FM. How Lewis Acids Catalyze Diels–Alder Reactions. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914582] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Pascal Vermeeren
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Trevor A. Hamlin
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)Amsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit Amsterdam De Boelelaan 1083 1081 HV Amsterdam The Netherlands
| | - Israel Fernández
- Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA)Facultad de Ciencias QuímicasUniversidad Complutense de Madrid 28040 Madrid Spain
| | - F. Matthias Bickelhaupt
- Department of Theoretical ChemistryAmsterdam Institute of Molecular and Life Sciences (AIMMS)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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29
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Grimblat N, Sarotti AM. Looking at the big picture in activation strain model/energy decomposition analysis: the case of the ortho-para regioselectivity rule in Diels-Alder reactions. Org Biomol Chem 2020; 18:1104-1111. [PMID: 31950965 DOI: 10.1039/c9ob02671a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The regioselectivity of the Diels-Alder reaction is predicted by the ortho-para rule which has been explained from FMO theory. Using DFT calculations, the activation-strain model and energy decomposition analysis we studied the reaction of methyl acrylate with four unsymmetrical dienes. We found that if the analysis is carried out considering the TS structures, the selectivity would not be explained by the interaction energy as expected considering the FMO arguments. However, a thorough analysis along the reaction path revealed that the interaction energy is responsible for the regioselectivity. A deeper analysis with the EDA model showed that the decisive term that accounts for the HOMO-LUMO interactions favors the ortho and para paths, as predicted by FMO arguments.
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Affiliation(s)
- Nicolás Grimblat
- Instituto de Química Rosario (IQUIR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas. Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina.
| | - Ariel M Sarotti
- Instituto de Química Rosario (IQUIR-CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas. Universidad Nacional de Rosario, Suipacha 531, Rosario 2000, Argentina.
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30
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Understanding chemical reactivity using the activation strain model. Nat Protoc 2020; 15:649-667. [PMID: 31925400 DOI: 10.1038/s41596-019-0265-0] [Citation(s) in RCA: 168] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/29/2019] [Indexed: 12/20/2022]
Abstract
Understanding chemical reactivity through the use of state-of-the-art computational techniques enables chemists to both predict reactivity and rationally design novel reactions. This protocol aims to provide chemists with the tools to implement a powerful and robust method for analyzing and understanding any chemical reaction using PyFrag 2019. The approach is based on the so-called activation strain model (ASM) of reactivity, which relates the relative energy of a molecular system to the sum of the energies required to distort the reactants into the geometries required to react plus the strength of their mutual interactions. Other available methods analyze only a stationary point on the potential energy surface, but our methodology analyzes the change in energy along a reaction coordinate. The use of this methodology has been proven to be critical to the understanding of reactions, spanning the realms of the inorganic and organic, as well as the supramolecular and biochemical, fields. This protocol provides step-by-step instructions-starting from the optimization of the stationary points and extending through calculation of the potential energy surface and analysis of the trend-decisive energy terms-that can serve as a guide for carrying out the analysis of any given reaction of interest within hours to days, depending on the size of the molecular system.
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31
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Sun X, Soini TM, Poater J, Hamlin TA, Bickelhaupt FM. PyFrag 2019-Automating the exploration and analysis of reaction mechanisms. J Comput Chem 2019; 40:2227-2233. [PMID: 31165500 PMCID: PMC6771738 DOI: 10.1002/jcc.25871] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 05/16/2019] [Accepted: 05/16/2019] [Indexed: 02/06/2023]
Abstract
We present a substantial update to the PyFrag 2008 program, which was originally designed to perform a fragment-based activation strain analysis along a provided potential energy surface. The original PyFrag 2008 workflow facilitated the characterization of reaction mechanisms in terms of the intrinsic properties, such as strain and interaction, of the reactants. The new PyFrag 2019 program has automated and reduced the time-consuming and laborious task of setting up, running, analyzing, and visualizing computational data from reaction mechanism studies to a single job. PyFrag 2019 resolves three main challenges associated with the automated computational exploration of reaction mechanisms: it (1) computes the reaction path by carrying out multiple parallel calculations using initial coordinates provided by the user; (2) monitors the entire workflow process; and (3) tabulates and visualizes the final data in a clear way. The activation strain and canonical energy decomposition results that are generated relate the characteristics of the reaction profile in terms of intrinsic properties (strain, interaction, orbital overlaps, orbital energies, populations) of the reactant species. © 2019 The Authors. Journal of Computational Chemistry published by Wiley Periodicals, Inc.
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Affiliation(s)
- Xiaobo Sun
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale ModelingVrije Universiteit AmsterdamDe Boelelaan 1083, 1081 HVAmsterdamNetherlands
| | - Thomas M. Soini
- Software for Chemistry & Materials B.V.De Boelelaan 1083, 1081 HVAmsterdamNetherlands
| | - Jordi Poater
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain and Departament de Química Inorgànica i Orgànica & IQTCUBUniversitat de Barcelona08028BarcelonaCataloniaSpain
| | - Trevor A. Hamlin
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale ModelingVrije Universiteit AmsterdamDe Boelelaan 1083, 1081 HVAmsterdamNetherlands
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry and Amsterdam Center for Multiscale ModelingVrije Universiteit AmsterdamDe Boelelaan 1083, 1081 HVAmsterdamNetherlands
- Institute for Molecules and MaterialsRadboud UniversityHeyendaalseweg 135, 6525 AJNijmegenNetherlands
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32
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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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33
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Svatunek D, Houk KN. autoDIAS: a python tool for an automated distortion/interaction activation strain analysis. J Comput Chem 2019; 40:2509-2515. [DOI: 10.1002/jcc.26023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/20/2019] [Accepted: 06/16/2019] [Indexed: 01/02/2023]
Affiliation(s)
- Dennis Svatunek
- Department of Chemistry and BiochemistryUniversity of California Los Angeles California
| | - Kendall N. Houk
- Department of Chemistry and BiochemistryUniversity of California Los Angeles California
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