1
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Xu B, Zhang Z, Tantillo DJ, Dai M. Concise Total Syntheses of ( -)-Crinipellins A and B Enabled by a Controlled Cargill Rearrangement. J Am Chem Soc 2024; 146:21250-21256. [PMID: 39052841 PMCID: PMC11311239 DOI: 10.1021/jacs.4c07900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/17/2024] [Accepted: 07/17/2024] [Indexed: 07/27/2024]
Abstract
Herein, we report concise total syntheses of diterpene natural products (-)-crinipellins A and B with a tetraquinane skeleton, three adjacent all-carbon quaternary centers, and multiple oxygenated and labile functional groups. Our synthesis features a convergent Kozikowski β-alkylation to unite two readily available building blocks with all the required carbon atoms, an intramolecular photochemical [2 + 2] cycloaddition to install three challenging and adjacent all-carbon quaternary centers and a 5-6-4-5 tetracyclic skeleton, and a controlled Cargill rearrangement to rearrange the 5-6-4-5 tetracyclic skeleton to the desired tetraquinane skeleton. These strategically enabling transformations allowed us to complete total syntheses of (-)-crinipellins A and B in 12 and 13 steps, respectively. The results of quantum chemical computations revealed that the Bronsted acid-catalyzed Cargill rearrangements likely involve stepwise paths to products and the AlR3-catalyzed Cargill rearrangements likely involve a concerted path with asynchronous alkyl shifting events to form the desired product.
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Affiliation(s)
- Bo Xu
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Ziyao Zhang
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
| | - Dean J. Tantillo
- Department
of Chemistry, University of California—Davis, Davis, California 95616, United States
| | - Mingji Dai
- Department
of Chemistry, Emory University, Atlanta, Georgia 30322, United States
- Department
of Pharmacology and Chemical Biology, Emory
University, Atlanta, Georgia 30322, United States
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2
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Hashimoto Y, Kong WY, Tantillo DJ. Discovery of a Formal Dyotropic Rearrangement during Acid-Mediated Dioxabicyclo[4.2.1]nonanone Formation. Org Lett 2024; 26:5441-5446. [PMID: 38900922 DOI: 10.1021/acs.orglett.4c01616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
A new reaction mechanism for the construction of dioxabicyclo[4.2.1]nonanone skeletons via a cation cascade has been proposed and examined by DFT and ab initio computations. This mechanism features the following steps: (1) intramolecular Friedel-Crafts-type cyclization with a methyl oxocarbenium cation formed by carboxylate disconnection, (2) electron-rich aromatic ring assisted methoxide loss followed by lactone formation, and (3) stepwise dyotropic rearrangement resulting in skeletal isomerization from a dioxabicyclo[3.2.2]nonanone to the dioxabicyclo[4.2.1]nonanone product observed experimentally. The high regioselectivity and driving force for the overall rearrangement were rationalized, and Lewis and Brønsted acid mediated reactivities were compared.
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Affiliation(s)
- Yoshimitsu Hashimoto
- Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo 194-8543, Japan
- Department of Chemistry, University of California-Davis, Davis, California 95616, United States
| | - Wang-Yeuk Kong
- Department of Chemistry, University of California-Davis, Davis, California 95616, United States
| | - Dean J Tantillo
- Department of Chemistry, University of California-Davis, Davis, California 95616, United States
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3
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Yu F, Xu L. A concise and stereoselective synthesis of the BCDF tetracyclic ring system of C 19-diterpenoid alkaloids. RSC Adv 2024; 14:21102-21106. [PMID: 38966809 PMCID: PMC11223105 DOI: 10.1039/d4ra02821j] [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: 04/16/2024] [Accepted: 06/18/2024] [Indexed: 07/06/2024] Open
Abstract
A new synthetic route for the BCDF tetracyclic ring system of C19-diterpenoid alkaloids (C19-DTAs) has been developed. The key step is a Pd-catalyzed transannular alkenylation that installs a functionalized bridged F ring. The overall strategy is concise and stereoselective, and it provides a valuable new tool for the synthesis of C19-DTAs. The synthesis begins with a bridged [3.2.1] ring system, which is converted to a key intermediate through a series of highly regio- and stereoselective processes. The introduction of an allylic side chain with high precision is accomplished, culminating in a Pd-catalyzed transannular alkenylation that installs a functionalized bridged F ring to yield the BCDF tetracyclic analog of C19-DTAs.
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Affiliation(s)
- Fangzhou Yu
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University Chengdu 610041 P. R. China
| | - Liang Xu
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Ministry of Education, West China School of Pharmacy, Sichuan University Chengdu 610041 P. R. China
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4
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Xu H, Lauterbach L, Goldfuss B, Schnakenburg G, Dickschat JS. Fragmentation and [4 + 3] cycloaddition in sodorifen biosynthesis. Nat Chem 2023:10.1038/s41557-023-01223-z. [PMID: 37248344 DOI: 10.1038/s41557-023-01223-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 04/26/2023] [Indexed: 05/31/2023]
Abstract
Terpenes constitute the largest class of natural products. Their skeletons are formed by terpene cyclases (TCs) from acyclic oligoprenyl diphosphates through sophisticated enzymatic conversions. These enzyme reactions start with substrate ionization through diphosphate abstraction, followed by a cascade reaction via cationic intermediates. Based on isotopic-labelling experiments in combination with a computational study, the cyclization mechanism for sodorifen, a highly methylated sesquiterpene from the soil bacterium Serratia plymuthica, was resolved. A peculiar problem in its biosynthesis lies in the formation of several methyl groups from chain methylene carbons. The underlying mechanism involves a methyltransferase-mediated cyclization and unprecedented ring contraction with carbon extrusion from the chain to form a methyl group. A terpene cyclase subsequently catalyses a fragmentation into two reactive intermediates, followed by hydrogen transfers between them and recombination of the fragments by [4 + 3] cycloaddition. This study solves the intricate mechanistic problem of extra methyl group formation in sodorifen biosynthesis.
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Affiliation(s)
- Houchao Xu
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Lukas Lauterbach
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Bernd Goldfuss
- Institut für Organische Chemie, Universität zu Köln, Köln, Germany
| | - Gregor Schnakenburg
- Institut für Anorganische Chemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Jeroen S Dickschat
- Kekulé-Institut für Organische Chemie und Biochemie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.
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5
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Csenki JT, Tóth BL, Béke F, Varga B, P. Fehér P, Stirling A, Czégény Z, Bényei A, Novák Z. Synthesis of Hydrofluoroolefin‐Based Iodonium Reagent via Dyotropic Rearrangement and Its Utilization in Fluoroalkylation. Angew Chem Int Ed Engl 2022; 61:e202208420. [PMID: 35876269 PMCID: PMC9540448 DOI: 10.1002/anie.202208420] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Indexed: 11/25/2022]
Abstract
[1,2]‐shift of atoms in alkyl fragments belongs to the class of dyotropic rearrangements. Various atoms, including halogens can be involved in the migration, however participation of iodine is unprecedented. Herein, we report our experimental and DFT studies on the oxidation triggered dyotropic rearrangement of iodo and chloro functions via butterfly‐type transition state to demonstrate the migrating ability of λ3‐iodane centre. With the exploitation of dyotropic rearrangement we designed and synthesized a novel fluoroalkyl iodonium reagent from industrial feedstock gas HFO‐1234yf. We demonstrated that the hypervalent reagent serves as an excellent fluoroalkylation agent for various amines and nitrogen heterocycles.
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Affiliation(s)
- János T. Csenki
- ELTE “Lendület” Catalysis and Organic Synthesis Research Group DepartmentInstitute of ChemistryEötvös Loránd UniversityPázmány Péter stny. 1/A1117BudapestHungary
| | - Balázs L. Tóth
- ELTE “Lendület” Catalysis and Organic Synthesis Research Group DepartmentInstitute of ChemistryEötvös Loránd UniversityPázmány Péter stny. 1/A1117BudapestHungary
| | - Ferenc Béke
- ELTE “Lendület” Catalysis and Organic Synthesis Research Group DepartmentInstitute of ChemistryEötvös Loránd UniversityPázmány Péter stny. 1/A1117BudapestHungary
| | - Bálint Varga
- ELTE “Lendület” Catalysis and Organic Synthesis Research Group DepartmentInstitute of ChemistryEötvös Loránd UniversityPázmány Péter stny. 1/A1117BudapestHungary
| | - Péter P. Fehér
- Research Centre for Natural SciencesEötvös Loránd Research NetworkMagyar Tudósok körútja 21117BudapestHungary
| | - András Stirling
- Research Centre for Natural SciencesEötvös Loránd Research NetworkMagyar Tudósok körútja 21117BudapestHungary
- Department of ChemistryEszterházy Károly Catholic UniversityLeányka u. 63300EgerHungary
| | - Zsuzsanna Czégény
- Research Centre for Natural SciencesEötvös Loránd Research NetworkMagyar Tudósok körútja 21117BudapestHungary
| | - Attila Bényei
- Department of Physical ChemistryUniversity of DebrecenEgyetem tér 14032DebrecenHungary
| | - Zoltán Novák
- ELTE “Lendület” Catalysis and Organic Synthesis Research Group DepartmentInstitute of ChemistryEötvös Loránd UniversityPázmány Péter stny. 1/A1117BudapestHungary
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6
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Csenki JT, Tóth BL, Béke F, Varga B, Fehér PP, Stirling A, Czégény Z, Bényei A, Novák Z. Synthesis of Hydrofluoroolefin‐based Iodonium Reagent via Dyotropic Rearrangement and Its Utilization in Fluoroalkylation. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- János Tivadar Csenki
- Eötvös Loránd Tudományegyetem: Eotvos Lorand Tudomanyegyetem Institute of Chemistry HUNGARY
| | - Balázs László Tóth
- Eötvös Loránd Tudományegyetem: Eotvos Lorand Tudomanyegyetem Institute of Chemistry HUNGARY
| | - Ferenc Béke
- Eötvös Loránd Tudományegyetem: Eotvos Lorand Tudomanyegyetem Institute of Chemistry HUNGARY
| | - Bálint Varga
- Eötvös Loránd Tudományegyetem: Eotvos Lorand Tudomanyegyetem Institute of Chemistry HUNGARY
| | - Péter Pál Fehér
- Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont HUNGARY
| | - András Stirling
- Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont HUNGARY
| | - Zsuzsanna Czégény
- Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont HUNGARY
| | - Attila Bényei
- University of Debrecen: Debreceni Egyetem Department of Physical Chemistry HUNGARY
| | - Zoltán Novák
- Eotvos Lorand Tudomanyegyetem Institute of Chemistry Pázány Péter stny 1/a 1117 Budapest HUNGARY
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7
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Novitskiy IM, Kutateladze AG. Peculiar Reaction Products and Mechanisms Revisited with Machine Learning-Augmented Computational NMR. J Org Chem 2022; 87:8589-8598. [PMID: 35723522 DOI: 10.1021/acs.joc.2c00749] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
DU8ML, a fast and accurate machine learning-augmented density functional theory (DFT) method for computing nuclear magnetic resonance (NMR) spectra, proved effective for high-throughput revision of misassigned natural products. In this paper, we disclose another important aspect of its application: correction of unusual reaction mechanisms originally proposed because of incorrect product structures.
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Affiliation(s)
- Ivan M Novitskiy
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
| | - Andrei G Kutateladze
- Department of Chemistry and Biochemistry, University of Denver, Denver, Colorado 80208, United States
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8
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Ping Y, Pan Q, Guo Y, Liu Y, Li X, Wang M, Kong W. Switchable 1,2-Rearrangement Enables Expedient Synthesis of Structurally Diverse Fluorine-Containing Scaffolds. J Am Chem Soc 2022; 144:11626-11637. [DOI: 10.1021/jacs.2c02487] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Yuanyuan Ping
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, P. R. China
| | - Qi Pan
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, P. R. China
| | - Ya Guo
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, P. R. China
| | - Yongli Liu
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, P. R. China
| | - Xiao Li
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, P. R. China
| | - Minyan Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P. R. China
| | - Wangqing Kong
- The Institute for Advanced Studies, Wuhan University, Wuhan 430072, P. R. China
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9
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Zhang J, Ma Y, Qiu K, Li B, Xue Z, Tian B, Tang Y. Elucidating the selectivity of dyotropic rearrangements of β-lactones: a computational survey. Org Chem Front 2022. [DOI: 10.1039/d1qo01591e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A comprehensive computational study on dyotropic rearrangements of β-lactones has been performed for the first time, which provides a valuable guidance for predicting and controlling the selectivity of the reactions.
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Affiliation(s)
- Jingyang Zhang
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Yumiao Ma
- BSJ Institute, Beijing, 100084, China
| | - Ke Qiu
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Bo Li
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, 91125, USA
| | - Zhengwen Xue
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Boxue Tian
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
| | - Yefeng Tang
- School of Pharmaceutical Sciences, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing 100084, China
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10
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O'Hair RAJ. ORGANOMETALLIC GAS-PHASE ION CHEMISTRY AND CATALYSIS: INSIGHTS INTO THE USE OF METAL CATALYSTS TO PROMOTE SELECTIVITY IN THE REACTIONS OF CARBOXYLIC ACIDS AND THEIR DERIVATIVES. MASS SPECTROMETRY REVIEWS 2021; 40:782-810. [PMID: 32965774 DOI: 10.1002/mas.21654] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/02/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Carboxylic acids are valuable organic substrates as they are widely available, easy to handle, and exhibit structural and functional variety. While they are used in many standard synthetic protocols, over the past two decades numerous studies have explored new modes of metal-mediated reactivity of carboxylic acids and their derivatives. Mass spectrometry-based studies can provide fundamental mechanistic insights into these new modes of reactivity. Here gas-phase models for the following catalytic transformations of carboxylic acids and their derivatives are reviewed: protodecarboxylation; dehydration; decarbonylation; reaction as coordinated bases in C-H bond activation; remote functionalization and decarboxylative C-C bond coupling. In each case the catalytic problem is defined, insights from gas-phase studies are highlighted, comparisons with condensed-phase systems are made and perspectives are reached. Finally, the potential role for mechanistic studies that integrate both gas- and condensed-phase studies is highlighted by recent studies on the discovery of new catalysts for the selective decomposition of formic acid and the invention of the new extrusion-insertion class of reactions for the synthesis of amides, thioamides, and amidines. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.
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Affiliation(s)
- Richard A J O'Hair
- School of Chemistry, University of Melbourne, Victoria, 3010, Australia
- Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, Victoria, 3010, Australia
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11
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Xing YY, Chen SS, Chen DZ, Tantillo DJ. Effects of electrostatic drag on the velocity of hydrogen migration - pre- and post-transition state enthalpy/entropy compensation. Phys Chem Chem Phys 2020; 22:26955-26960. [PMID: 33206074 DOI: 10.1039/d0cp05000h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Ab initio molecular dynamics calculations were used to explore the underlying factors that modulate the velocity of hydrogen migration for 1,2 hydrogen shifts in carbocations in which different groups interact noncovalently with the migrating hydrogen. Our results indicate that stronger electrostatic interactions between the migrating hydrogen and nearby π-systems lead to slower hydrogen migration, an effect tied to entropic contributions from the hydrogen + neighboring group substructures.
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Affiliation(s)
- Yang-Yang Xing
- College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Shandong Normal University, Jinan 250014, P. R. China.
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12
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Chuang HH, Tantillo DJ, Hsu CP. Construction of Two-Dimensional Potential Energy Surfaces of Reactions with Post-Transition-State Bifurcations. J Chem Theory Comput 2020; 16:4050-4060. [PMID: 32470303 DOI: 10.1021/acs.jctc.0c00172] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reactions with post-transition-state bifurcations (PTSBs) involve initial ambimodal transition-state structures followed by an unstable region leading to two possible products. PTSBs are seen in many organic, organometallic, and biosynthetic reactions, but analyzing the origins of selectivity for these reactions is challenging, in large part due to the complex nature of the potential energy surfaces involved, which precludes analyses based on single intrinsic reaction coordinate (IRC; steepest-descent path in mass-weighted coordinate). While selectivity can be predicted using molecular dynamics simulation, connecting results from such calculations to the topography of potential energy surfaces is difficult. In the present work, a method for generating two-dimensional potential energy surfaces for PTSBs is described. The first dimension starts with the IRC for the first transition-state structure, followed by a modified reaction coordinate that reaches the second transition-state structure, which interconverts the two products of a bifurcating reaction path. The IRC for the second transition-state structure constitutes the second dimension. In addition, a method for mapping trajectories from Born-Oppenheimer molecular dynamics simulations onto these surfaces is described. Both approaches are illustrated with representative examples from the field of organic chemistry. The 2D-PESs for five asymmetric cases tested have clear tilted topography after the first transition-state structure, and the tilted direction correlates well with the selectivity observed from previous dynamic simulation. Instead of selecting reaction coordinates by chemical intuition, our method provides a general means to construct two-dimensional potential energy surfaces for reactions with post-transition-state bifurcations.
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Affiliation(s)
- Hsiao-Han Chuang
- Department of Chemistry, National Taiwan University, 11529 Taipei, Taiwan.,Institute of Chemistry, Academia Sinica, 11529 Taipei, Taiwan.,Nanoscience and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, 11529 Taipei, Taiwan
| | - Dean J Tantillo
- Department of Chemistry, University of California-Davis, Davis, California 95616, United States
| | - Chao-Ping Hsu
- Institute of Chemistry, Academia Sinica, 11529 Taipei, Taiwan
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13
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Maejima S, Yamaguchi E, Itoh A. Visible Light/Molecular-Iodine-Mediated Intermolecular Spirolactonization Reaction of Olefins with Cyclic Ketones. J Org Chem 2019; 84:9519-9531. [DOI: 10.1021/acs.joc.9b01081] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Saki Maejima
- Gifu Pharmaceutical University, 1-25-4, Daigaku-nishi, Gifu 501-1196, Japan
| | - Eiji Yamaguchi
- Gifu Pharmaceutical University, 1-25-4, Daigaku-nishi, Gifu 501-1196, Japan
| | - Akichika Itoh
- Gifu Pharmaceutical University, 1-25-4, Daigaku-nishi, Gifu 501-1196, Japan
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14
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Honda K, Tanaka K, Sukekawa M, Hoshino Y, Kishimoto M. CsF-Promoted Desilylation and Ring-Contraction Reaction of Electron-Deficient 3-Silyl-2H-chromenes to 2-Benzylbenzofurans. HETEROCYCLES 2019. [DOI: 10.3987/com-18-s(f)5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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15
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Campos RB, Tantillo DJ. Designing Reactions with Post-Transition-State Bifurcations: Asynchronous Nitrene Insertions into C–C σ Bonds. Chem 2019. [DOI: 10.1016/j.chempr.2018.10.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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16
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Tanaka K, Hoshino Y, Honda K. Development of Regioselective Inverse-Electron-Demand [4+2] Cycloaddition with Electron-Rich Arylalkynes for Access to Multi-Substituted Condensed Oxapolycyclic Compounds. J SYN ORG CHEM JPN 2018. [DOI: 10.5059/yukigoseikyokaishi.76.1341] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Yujiro Hoshino
- Graduate School of Environment and Information Sciences, Yokohama National University
| | - Kiyoshi Honda
- Graduate School of Environment and Information Sciences, Yokohama National University
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17
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McCulley CH, Tantillo DJ. Secondary Carbocations in the Biosynthesis of Pupukeanane Sesquiterpenes. J Phys Chem A 2018; 122:8058-8061. [PMID: 30209949 DOI: 10.1021/acs.jpca.8b07961] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The results of quantum chemical calculations on putative biosynthetic carbocation cyclization/rearrangements leading to pupukeanane and related sesquiterpenes indicate that a secondary carbocation proposed as an intermediate is not a minimum on the potential energy surface and instead resides in a region of the potential energy surface associated with a plateau containing multiple exit channels.
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Affiliation(s)
- Christina H McCulley
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
| | - Dean J Tantillo
- Department of Chemistry , University of California-Davis , Davis , California 95616 , United States
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18
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Rablen PR. Acid-catalyzed conversion of caryolan-1-ol to isoclovene: A computational investigation of the multi-step carbocation rearrangement. Tetrahedron 2018. [DOI: 10.1016/j.tet.2018.04.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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19
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Goh SS, Champagne PA, Guduguntla S, Kikuchi T, Fujita M, Houk KN, Feringa BL. Stereospecific Ring Contraction of Bromocycloheptenes through Dyotropic Rearrangements via Nonclassical Carbocation-Anion Pairs. J Am Chem Soc 2018; 140:4986-4990. [PMID: 29596748 PMCID: PMC5909176 DOI: 10.1021/jacs.8b00821] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Experimental
and theoretical evidence is reported for a rare type
I dyotropic rearrangement involving a [1,2]-alkene shift, leading
to the regio- and stereospecific ring contraction of bromocycloheptenes.
This reaction occurs under mild conditions, with or without a Lewis
acid catalyst. DFT calculations show that the reaction proceeds through
a nonclassical carbocation–anion pair, which is crucial for
the low activation barrier and enantiospecificity. The chiral cyclopropylcarbinyl cation may be a transition
state or an intermediate, depending on the reaction conditions.
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Affiliation(s)
- Shermin S Goh
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands
| | - Pier Alexandre Champagne
- Department of Chemistry and Biochemistry , University of California-Los Angeles , 607 Charles E. Young Drive East , Box 951569, Los Angeles , California 90095-1569 , United States
| | - Sureshbabu Guduguntla
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands
| | - Takashi Kikuchi
- Department of Applied Chemistry , University of Tokyo , 7-3-1 Hongo, Bukyo-ku , Tokyo 113-8656 , Japan.,Rigaku Corporation , 3-9-12 Matsubara-cho, Akishima-shi , Tokyo 196-8628 , Japan
| | - Makoto Fujita
- Department of Applied Chemistry , University of Tokyo , 7-3-1 Hongo, Bukyo-ku , Tokyo 113-8656 , Japan
| | - K N Houk
- Department of Chemistry and Biochemistry , University of California-Los Angeles , 607 Charles E. Young Drive East , Box 951569, Los Angeles , California 90095-1569 , United States
| | - Ben L Feringa
- Stratingh Institute for Chemistry , University of Groningen , Nijenborgh 4 , 9747 AG Groningen , The Netherlands
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20
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Theoretical study on DABCO-catalyzed ring expansion of cyclopropyl ketone: Mechanism, chemoselectivity, and role of catalyst. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2017.11.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Li X, Wei D, Li Z. Theoretical Study on DBU-Catalyzed Insertion of Isatins into Aryl Difluoronitromethyl Ketones: A Case for Predicting Chemoselectivity Using Electrophilic Parr Function. ACS OMEGA 2017; 2:7029-7038. [PMID: 31457285 PMCID: PMC6645149 DOI: 10.1021/acsomega.7b00907] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 10/05/2017] [Indexed: 06/10/2023]
Abstract
The possible mechanisms of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-catalyzed chemoselective insertion of N-methyl isatin into aryl difluoronitromethyl ketone to synthesize 3,3-disubstituted and 2,2-disubstituted oxindoles have been studied in this work. As revealed by calculated results, the reaction occurs via two competing paths, including α and β carbonyl paths, and each path contains five steps, that is, nucleophilic addition of DBU to ketone, C-C bond cleavage affording difluoromethylnitrate anion and phenylcarbonyl-DBU cation, nucleophilic addition of difluoromethylnitrate anion to carbonyl carbon of N-methyl isatin, acyl transfer process, and dissociation of DBU and product. The computational results suggest that nucleophilic additions on different carbonyl carbons of N-methyl isatin via α and β carbonyl paths would lead to different products in the third step, and β carbonyl path associated with the main product 3,3-disubstituted oxindole is more energetically favorable, which is consistent with the experimental observations. Noteworthy, electrophilic Parr function can be successfully applied for exactly predicting the activity of reaction site and reasonably explaining the chemoselectivity. In addition, the distortion/interaction and noncovalent interaction analyses show that much more hydrogen bond interactions should be responsible for the lower energy of the transition state associated with β carbonyl path. The obtained insights would be valuable for the rational design of efficient organocatalysts for this kind of reactions with high selectivities.
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22
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Hare SR, Farnham JM, Tantillo DJ. Putative biosynthetic cycloadditions en route to the diterpenoid (+)-chatancin. Tetrahedron 2017. [DOI: 10.1016/j.tet.2016.11.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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23
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Santalla H, Faza ON, Gómez G, Fall Y, Silva López C. From Hydrindane to Decalin: A Mild Transformation through a Dyotropic Ring Expansion. Org Lett 2017. [PMID: 28641016 DOI: 10.1021/acs.orglett.7b01621] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
An unexpected ring expansion converting hydrindane cores into decalins has been observed. The process occurs under very mild conditions and with exquisite transfer of chiral information. The ring expansion provides access to decorated decalins with complete stereocontrol. The reaction mechanism is studied in order to gain insight into the underlying causes for the low thermal requirements in this reaction and the nature of the chirality transfer process. Interestingly, both result from an unprecedented dyotropic reaction involving a mesylate group.
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Affiliation(s)
- Hugo Santalla
- Departamento de Química Orgánica, Campus Lagoas-Marcosende , 36310 Vigo, Spain
| | - Olalla Nieto Faza
- Departamento de Química Orgánica, Campus Lagoas-Marcosende , 36310 Vigo, Spain
| | - Generosa Gómez
- Departamento de Química Orgánica and Instituto de Investigación Sanitaria Galicia Sur (IISGS), Campus Lagoas-Marcosende , 36310 Vigo, Spain
| | - Yagamare Fall
- Departamento de Química Orgánica and Instituto de Investigación Sanitaria Galicia Sur (IISGS), Campus Lagoas-Marcosende , 36310 Vigo, Spain
| | - Carlos Silva López
- Departamento de Química Orgánica, Campus Lagoas-Marcosende , 36310 Vigo, Spain
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24
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Cycloaddition of sulfonyl azides and cyanogen azide to enamines. Quantum-chemical calculations concerning the spontaneous rearrangement of the adduct into ring-contracted amidines. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.01.081] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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25
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Hugelshofer CL, Magauer T. Dyotropic rearrangements in natural product total synthesis and biosynthesis. Nat Prod Rep 2017; 34:228-234. [DOI: 10.1039/c7np00005g] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Some recent examples of dyotropic rearrangements involved in complex natural product total synthesis and biosynthesis are highlighted.
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Affiliation(s)
| | - Thomas Magauer
- Department of Chemistry and Pharmacy
- Ludwig-Maximilians-Univeristy Munich
- 81377 Munich
- Germany
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26
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Kim JS, Brandt LM, Heard GL, Holmes BE. Computational study of the threshold energy for the 1,2-interchange of X and R (X, R = halogens, pseudohalogens, and monovalent hydrocarbon groups) on CH2XCH2R. CAN J CHEM 2016. [DOI: 10.1139/cjc-2016-0293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Transition state geometries and threshold energies, E0, were computed for an unusual unimolecular isomerization reaction that exchanges two groups (X, R) on CH2XCH2R. An objective is to determine the most energetically feasible interchanges to guide experimental investigations. The interchanging species included halogens (F, Cl, Br) and pseudohalogens and monovalent hydrocarbons (H, SH, CH3, NH2, OH, OCF3, OCH3, CH=CH2, CH2CH3, CH2OH, C≡CH, CH2CF3, CCl3, CF3) attached to a two carbon backbone. Ground state and transition state geometries were optimized with the B3PW91 level of theory and 6-311+G(2d,p) basis set. The Br–Br interchange had the lowest E0 (141 kJ/mol), and CH3–H had the highest E0 (582 kJ/mol). In general, larger atoms or groups with lone pairs of electrons such as halogens, SH, OH, OCH3, OCF3, and NH2 tend to lower the E0 barrier for interchange, making them the most likely to be experimentally observed.
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Affiliation(s)
- Ju-Sung Kim
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
| | - Laura M. Brandt
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
| | - George L. Heard
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
| | - Bert E. Holmes
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
- Department of Chemistry, University of North Carolina Asheville, One University Heights, North Carolina, 28804-8511, USA
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27
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Wenthold PG, Koirala D, Somogyi A, Poutsma JC. Infrared spectroscopic confirmation of α-lactone formation in the dissociation of a gaseous amino acid. J PHYS ORG CHEM 2016. [DOI: 10.1002/poc.3606] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Paul G. Wenthold
- Department of Chemistry; Purdue University; 560 Oval Drive West Lafayette IN 47907 USA
| | - Damodar Koirala
- Department of Chemistry; Purdue University; 560 Oval Drive West Lafayette IN 47907 USA
| | - Arpad Somogyi
- Campus Chemical Instrumentation Center, Mass Spectrometry and Proteomics Laboratory; The Ohio State University; 460 West 12th Ave Columbus OH 43210 USA
| | - J. C. Poutsma
- The College of William and Mary; Williamsburg VA 23187 USA
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28
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Nisa RU, Hashmi MA, Sajjad S, Mahmood T, Iqbal J, Ayub K. Quantum mechanical investigation on acceleration of electrocyclic reactions through transition metal catalysis. J Organomet Chem 2016. [DOI: 10.1016/j.jorganchem.2016.02.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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29
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Hare SR, Tantillo DJ. Dynamic behavior of rearranging carbocations - implications for terpene biosynthesis. Beilstein J Org Chem 2016; 12:377-90. [PMID: 27340434 PMCID: PMC4902080 DOI: 10.3762/bjoc.12.41] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/15/2016] [Indexed: 11/23/2022] Open
Abstract
This review describes unexpected dynamical behaviors of rearranging carbocations and the modern computational methods used to elucidate these aspects of reaction mechanisms. Unique potential energy surface topologies associated with these rearrangements have been discovered in recent years that are not only of fundamental interest, but also provide insight into the way Nature manipulates chemical space to accomplish specific chemical transformations. Cautions for analyzing both experimental and theoretical data on carbocation rearrangements are included throughout.
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Affiliation(s)
- Stephanie R Hare
- Department of Chemistry, University of California–Davis, 1 Shields Avenue, Davis, CA 95616, USA
| | - Dean J Tantillo
- Department of Chemistry, University of California–Davis, 1 Shields Avenue, Davis, CA 95616, USA
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30
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Sheikh NS. Type-I dyotropic rearrangement for 1,2-disubstituted cyclohexanes: substitution effect on activation energy. RSC Adv 2016. [DOI: 10.1039/c5ra25482e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Migratory aptitude and contribution of specific structural features of synthetically valuable functional groups and halogen atoms in type-I dyotropic rearrangement for both symmetric and unsymmetrical 1,2-disubstituted cyclohexanes are computed.
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Affiliation(s)
- Nadeem S. Sheikh
- Department of Chemistry
- Faculty of Science
- King Faisal University
- Al-Ahsa 31982
- Saudi Arabia
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31
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Koirala D, Kodithuwakkuge SR, Wenthold PG. Mass spectrometric study of the decomposition pathways of canonical amino acids and α-lactones in the gas phase. J PHYS ORG CHEM 2015. [DOI: 10.1002/poc.3464] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Damodar Koirala
- Department of Chemistry; Purdue University; 560 Oval Drive West Lafayette IN 47906 USA
| | | | - Paul G. Wenthold
- Department of Chemistry; Purdue University; 560 Oval Drive West Lafayette IN 47906 USA
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32
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Croisant MF, Van Hoveln R, Schomaker JM. Formal Dyotropic Rearrangements in Organometallic Transformations. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500561] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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33
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Pham HV, Karns AS, Vanderwal CD, Houk KN. Computational and Experimental Investigations of the Formal Dyotropic Rearrangements of Himbert Arene/Allene Cycloadducts. J Am Chem Soc 2015; 137:6956-64. [DOI: 10.1021/jacs.5b03718] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hung V. Pham
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
| | - Alexander S. Karns
- 1102
Natural Sciences II, Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Christopher D. Vanderwal
- 1102
Natural Sciences II, Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive, Los Angeles, California 90095-1569, United States
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34
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Van Hoveln R, Hudson BM, Wedler HB, Bates DM, Le Gros G, Tantillo DJ, Schomaker JM. Mechanistic studies of copper(I)-catalyzed 1,3-halogen migration. J Am Chem Soc 2015; 137:5346-54. [PMID: 25828031 PMCID: PMC4701576 DOI: 10.1021/ja511236d] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
An ongoing challenge in modern catalysis is to identify and understand new modes of reactivity promoted by earth-abundant and inexpensive first-row transition metals. Herein, we report a mechanistic study of an unusual copper(I)-catalyzed 1,3-migration of 2-bromostyrenes that reincorporates the bromine activating group into the final product with concomitant borylation of the aryl halide bond. A combination of experimental and computational studies indicated this reaction does not involve any oxidation state changes at copper; rather, migration occurs through a series of formal sigmatropic shifts. Insight provided from these studies will be used to expand the utility of aryl copper species in synthesis and develop new ligands for enantioselective copper-catalyzed halogenation.
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Affiliation(s)
- Ryan Van Hoveln
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Brandi M. Hudson
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Henry B. Wedler
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Desiree M. Bates
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Gabriel Le Gros
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Dean J. Tantillo
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Jennifer M. Schomaker
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
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35
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Hong YJ, Tantillo DJ. How cyclobutanes are assembled in nature--insights from quantum chemistry. Chem Soc Rev 2015; 43:5042-50. [PMID: 24710596 DOI: 10.1039/c3cs60452g] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biosynthetic production of cyclobutanes leads to many complex natural products. Recently, theoretical work employing quantum chemical calculations has shed light on many of the details of cyclobutane-formation, in particular, for terpene natural products. Specific insights and general principles derived from these theoretical studies are described herein.
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Affiliation(s)
- Young J Hong
- Department of Chemistry, University of California-Davis, Davis, CA 95616, USA.
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36
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Pemberton RP, Ho KC, Tantillo DJ. Modulation of inherent dynamical tendencies of the bisabolyl cation via preorganization in epi-isozizaene synthase. Chem Sci 2015; 6:2347-2353. [PMID: 29308148 PMCID: PMC5645776 DOI: 10.1039/c4sc03782k] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Accepted: 01/30/2015] [Indexed: 01/09/2023] Open
Abstract
The relative importance of preorganization, selective transition state stabilization and inherent reactivity are assessed through quantum chemical and docking calculations for a sesquiterpene synthase (epi-isozizaene synthase, EIZS). Inherent reactivity of the bisabolyl cation, both static and dynamic, appears to determine the pathway to product, although preorganization and selective binding of the final transition state structure in the multi-step carbocation cascade that forms epi-isozizaene appear to play important roles.
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Affiliation(s)
- Ryan P Pemberton
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , CA 95616 , USA .
| | - Krystina C Ho
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , CA 95616 , USA .
| | - Dean J Tantillo
- Department of Chemistry , University of California, Davis , One Shields Avenue , Davis , CA 95616 , USA .
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37
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Villar López R, Nieto Faza O, Silva López C. Diradical ring closing reactions displaying Woodward–Hoffmann behaviour and torquoselectivity. RSC Adv 2015. [DOI: 10.1039/c5ra01742d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The applicability of the Woodward–Hoffmann rules seems to expand beyond classical closed shell structures.
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38
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Chandar NB, Ganguly B. In silico study on the mechanism of formation of hydrazine and nitrogen in the reactions of excess hydroxylamine with 2,4-dinitrophenyl diethyl phosphate. NEW J CHEM 2015. [DOI: 10.1039/c4nj02300e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Decomposition study of 2,4-dinitrophenyl diethyl phosphate to hydrazine and nitrogen gas with excess of hydroxylamine using quantum chemical calculations.
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Affiliation(s)
- Nellore Bhanu Chandar
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility)
- CSIR-Central Salt & Marine Chemicals Research Institute
- Gujarat
- India
- Academy of Scientific and Innovative Research
| | - Bishwajit Ganguly
- Computation and Simulation Unit (Analytical Discipline and Centralized Instrument Facility)
- CSIR-Central Salt & Marine Chemicals Research Institute
- Gujarat
- India
- Academy of Scientific and Innovative Research
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39
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McClintock CE, Smith KC, Heard GL, Setser DW, Holmes BE. Effects of CF3 and CH3 Groups on the Threshold Energy for the Unimolecular Interchange Reaction of Cl- and F-Atoms in CF3CHFCH2Cl and CH3CHFCH2Cl. J Phys Chem A 2014; 118:2886-96. [DOI: 10.1021/jp412299p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Corey E. McClintock
- Department
of Chemistry, University of North Carolina at Asheville, One University
Heights, Asheville, North
Carolina 28804-8511, United States
| | - Kylie C. Smith
- Department
of Chemistry, University of North Carolina at Asheville, One University
Heights, Asheville, North
Carolina 28804-8511, United States
| | - George L. Heard
- Department
of Chemistry, University of North Carolina at Asheville, One University
Heights, Asheville, North
Carolina 28804-8511, United States
| | - D. W. Setser
- Kansas State University, Manhattan, Kansas 66506, United States
| | - Bert E. Holmes
- Department
of Chemistry, University of North Carolina at Asheville, One University
Heights, Asheville, North
Carolina 28804-8511, United States
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40
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Hong YJ, Tantillo DJ. Biosynthetic consequences of multiple sequential post-transition-state bifurcations. Nat Chem 2014; 6:104-11. [PMID: 24451585 DOI: 10.1038/nchem.1843] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 12/05/2013] [Indexed: 11/09/2022]
Abstract
Selectivity in chemical reactions that form complex molecular architectures from simpler precursors is usually rationalized by comparing competing transition-state structures that lead to different possible products. Herein we describe a system for which a single transition-state structure leads to the formation of many isomeric products via pathways that feature multiple sequential bifurcations. The reaction network described connects the pimar-15-en-8-yl cation to miltiradiene, a tricyclic diterpene natural product, and isomers via cyclizations and/or rearrangements. The results suggest that the selectivity of the reaction is controlled by (post-transition-state) dynamic effects, that is, how the carbocation structure changes in response to the distribution of energy in its vibrational modes. The inherent dynamical effects revealed herein (characterized through quasiclassical direct dynamics calculations using density functional theory) have implications not only for the general principles of selectivity prediction in systems with complex potential energy surfaces, but also for the mechanisms of terpene synthase enzymes and their evolution. These findings redefine the challenges faced by nature in controlling the biosynthesis of complex natural products.
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Affiliation(s)
- Young Joo Hong
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, California 95616, USA
| | - Dean J Tantillo
- Department of Chemistry, University of California-Davis, One Shields Avenue, Davis, California 95616, USA
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41
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Pemberton RP, Tantillo DJ. Lifetimes of carbocations encountered along reaction coordinates for terpene formation. Chem Sci 2014. [DOI: 10.1039/c4sc00674g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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42
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Lodewyk MW, Willenbring D, Tantillo DJ. Pentalenene formation mechanisms redux. Org Biomol Chem 2014; 12:887-94. [DOI: 10.1039/c3ob42005a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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43
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Tucker MK, Rossabi SM, McClintock CE, Heard GL, Setser DW, Holmes BE. Unimolecular isomerization of CH2FCD2Cl via the interchange of Cl and F atoms: assignment of the threshold energy to the 1,2-dyotropic rearrangement. J Phys Chem A 2013; 117:6717-23. [PMID: 23837645 DOI: 10.1021/jp4032767] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The room-temperature gas-phase recombination of CH2F and CD2Cl radicals was used to prepare CH2FCD2Cl molecules with 91 kcal mol(-1) of vibrational energy. Three unimolecular processes are in competition with collisional deactivation of CH2FCD2Cl; HCl and DF elimination to give CHF═CD2 and CH2═CDCl plus isomerization to give CH2ClCD2F by the interchange of F and Cl atoms. The Cl/F interchange reaction was observed, and the rate constant was assigned from measurement of CHCl═CD2 as a product, which is formed by HF elimination from CH2ClCD2F. These experiments plus previously published results from chemically activated CH2ClCH2F and electronic structure and RRKM calculations for the kinetic-isotope effects permit assignment of the three rate constants for CH2FCD2Cl (and for CH2ClCD2F). The product branching ratio for the interchange reaction versus elimination is 0.24 ± 0.04. Comparison of the experimental rate constant with the RRKM calculated rate constant permitted the assignment of a threshold energy of 62 ± 3 kcal mol(-1) for this type-1 dyotropic rearrangement. On the basis of electronic structure calculations, the nature of the transition state for the rearrangement reaction is discussed. The radical recombination reactions in the chemical system also generate vibrationally excited CD2ClCD2Cl and CH2FCH2F molecules, and the rate constants for DCl and HF elimination were measured in order to confirm that the photolysis of CD2ClI and (CH2F)2CO mixtures was giving reliable data for CH2FCD2Cl.
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Affiliation(s)
- Mary K Tucker
- Department of Chemistry, University of North Carolina-Asheville, One University Heights, Asheville, North Carolina 28804-8511, USA
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44
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Hudson BM, Harrison JG, Tantillo DJ. Assessing the viability of biosynthetic pathways for calophyline A formation—are pericyclic reactions involved? Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.03.109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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45
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Tantillo DJ, Schleyer PVR. Nonamethylcyclopentyl Cation Rearrangement Mysteries Solved. Org Lett 2013; 15:1725-7. [DOI: 10.1021/ol4005189] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dean J. Tantillo
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States, and Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
| | - Paul von Ragué Schleyer
- Department of Chemistry, University of California—Davis, 1 Shields Avenue, Davis, California 95616, United States, and Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States
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46
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Hong YJ, Giner JL, Tantillo DJ. Triple Shifts and Thioether Assistance in Rearrangements Associated with an Unusual Biomethylation of the Sterol Side Chain. J Org Chem 2013; 78:935-41. [DOI: 10.1021/jo3024208] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Young J. Hong
- Department of Chemistry, University of California−Davis, 1 Shields Avenue, Davis, California 95616, United States
| | - José-Luis Giner
- Department of Chemistry, State University of New York-ESF, 1 Forestry Drive,
Syracuse, New York 13210, United States
| | - Dean J. Tantillo
- Department of Chemistry, University of California−Davis, 1 Shields Avenue, Davis, California 95616, United States
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Damrauer R, Stanton JF. Studies of 1,2-Dihalo Shifts in Carbon–Carbon, Carbon–Silicon, and Silicon–Silicon Systems: A Computational Study. Organometallics 2012. [DOI: 10.1021/om301019s] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert Damrauer
- Chemistry Department, University of Colorado Denver, Campus Box 137, P.O. Box 173364, Denver, Colorado
80217-3364, United States
| | - John F. Stanton
- Chemistry and Biochemistry Department, University of Texas at Austin, Austin, Texas 78712-0165,
United States
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