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Li Y, Zhang M, Zhang Z. Mechanisms and Stereoselectivities in the NHC-Catalyzed [4 + 2] Annulation of 2-Bromoenal and 6-Methyluracil-5-carbaldehyde. J Org Chem 2023; 88:12997-13008. [PMID: 37642149 DOI: 10.1021/acs.joc.3c01015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
To disclose the reaction mechanism and selectivity in the NHC-catalyzed reaction of 2-bromoenal and 6-methyluracil-5-carbaldehyde, a systematic computational study has been performed. According to DFT computations, the catalytic cycle is divided into eight elementary steps: nucleophilic attack of the NHC on 2-bromoenal, 1,2-proton transfer, C-Br bond dissociation, 1,3-proton transfer, addition to 6-methyluracil-5-carbaldehyde, [2 + 2] cycloaddition, NHC dissociation, and decarboxylation. The Bronsted acid DABCO·H+ plays a crucial role in proton transfer and decarboxylation steps. The addition to 6-methyluracil-5-carbaldehyde determines both chemoselectivity and stereoselectivity, leading to R-configured carbocycle-fused uracil, in agreement with experimental results. NCI analysis indicates that the CH···N, CH···π, and LP···π interactions should be the key factor for determining the stereoselectivity. ELF analysis shows the main role of the NHC in promoting C-Br bond dissociation. The mechanistic insights obtained in the present work may guide the rational design of potential NHC catalysts.
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Affiliation(s)
- Yan Li
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China
| | - Mingchao Zhang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China
| | - Zhiqiang Zhang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China
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2
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Azaz T, Mourya H, Singh V, Ram B, Tiwari B. Reductive Alkenylation of Ketimines via Hydride Transfer from Aldehydes. J Org Chem 2023; 88:632-639. [PMID: 36475729 DOI: 10.1021/acs.joc.2c01508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The first direct N-heterocyclic carbene (NHC)-catalyzed preparation of allylic amines bearing a quaternary center (α-tertiary amine) from isatin-derived ketimines in the presence of vinyl selenones and aldehydes is reported. This multicomponent reaction is expected to proceed via unprecedented in situ reduction of imines through a hydride transfer from the aldehydes.
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Affiliation(s)
- Tazeen Azaz
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS-Campus, Raebareli Road, Lucknow 226014, India.,Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
| | - Hemlata Mourya
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS-Campus, Raebareli Road, Lucknow 226014, India
| | - Vikram Singh
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS-Campus, Raebareli Road, Lucknow 226014, India.,Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
| | - Bali Ram
- Department of Chemistry, Faculty of Science, Banaras Hindu University, Varanasi 221005, India
| | - Bhoopendra Tiwari
- Department of Biological and Synthetic Chemistry, Centre of Biomedical Research, SGPGIMS-Campus, Raebareli Road, Lucknow 226014, India
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Shen J, Zhang Y, Xue Y. Theoretical Insights into Enantioselective [3 + 2] Cycloaddition between Cinnamaldehyde and Cyclic N-Sulfonyl Trifluoromethylated Ketimine Catalyzed by N-Heterocyclic Carbene. J Phys Chem A 2022; 126:3124-3134. [PMID: 35549275 DOI: 10.1021/acs.jpca.2c00900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The density functional theory (DFT) method was used to investigate the mechanism and the origin of stereoselectivity of N-heterocyclic carbene (NHC)-catalyzed [3 + 2] cycloaddition between enals and cyclic imine N-sulfonyl trifluoromethyl ketimines at the M06-2X/SMD/6-311+G(d,p)//M06-2X/SMD/6-31G (d,p) level. The results show that the favorable reaction path consists of five steps: nucleophilic attack, proton transfer, the formation of the C-C bond, the tautomerism of the enol intermediate, the formation of the five-membered ring, and the regeneration of the catalyst. For the process of proton transfer, the base-assisted reaction can reduce the activation free energy and make the reaction easier to occur compared with the direct proton transfer process. The formation of the C-C bond is the crucial step of stereoselectivity, in which two chiral centers and four configurations of intermediates (RR/RS/SR/SS) were generated. The free energy barriers obtained and the noncovalent interaction analysis confirm that the dominant configuration is SS, becoming the final trans-type product observed in experiment. Furthermore, through the analyses of the conceptual DFT and natural atomic charges, it is revealed that NHC acts as a double catalyst, which can not only increase the nucleophilicity of reactants by Lewis base but also activate the C-H bond and promote the proton transfer process. The understanding of the mechanism obtained in this study should be helpful to the other organic catalytic reactions with high stereoselectivity.
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Affiliation(s)
- Jingyi Shen
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064, People's Republic of China
| | - Yan Zhang
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064, People's Republic of China
| | - Ying Xue
- College of Chemistry, Key Lab of Green Chemistry and Technology in Ministry of Education, Sichuan University, Chengdu 610064, People's Republic of China
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Li Y, Geng L, Song Z, Zhang Z. A DFT study of NHC-catalyzed reactions between 2-bromo-2-enals and acylhydrazones: mechanisms, and chemo- and stereoselectivities. NEW J CHEM 2022. [DOI: 10.1039/d2nj01078j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The reaction mechanisms and origins of the chemo- and stereoselectivities of NHC-catalyzed [4 + 2] annulation of 2-bromo-2-enals and acylhydrazones.
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Affiliation(s)
- Yan Li
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, P. R. China
| | - Lina Geng
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, P. R. China
| | - Zhiyi Song
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, P. R. China
| | - Zhiqiang Zhang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan, 114051, P. R. China
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Gil-Ordóñez M, Maestro A, Ortega P, Jambrina PG, Andrés JM. NHC-catalysed [3 + 2]-asymmetric annulation between pyrazolin-4,5-diones and enals: synthesis of novel spirocyclic pyrazolone γ-butyrolactones and computational study of mechanism and stereoselectivity. Org Chem Front 2022. [DOI: 10.1039/d1qo01462e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Herein we present the first asymmetric synthesis of spiropyrazolone γ-butyrolactones from 1H-pyrazol-4,5-diones and enals by an NHC-catalysed [3 + 2] annulation. DFT calculations carried out predict the experimental configuration of final adducts.
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Affiliation(s)
- Marta Gil-Ordóñez
- GIR-SintACat-Instituto Universitario CINQUIMA y Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, Paseo Belén 7, 47011 Valladolid, Spain
| | - Alicia Maestro
- GIR-SintACat-Instituto Universitario CINQUIMA y Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, Paseo Belén 7, 47011 Valladolid, Spain
| | - Pablo Ortega
- Departamento de Química Física, University of Salamanca, 37008, Salamanca, Spain
| | - Pablo G. Jambrina
- Departamento de Química Física, University of Salamanca, 37008, Salamanca, Spain
| | - José M. Andrés
- GIR-SintACat-Instituto Universitario CINQUIMA y Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Valladolid, Paseo Belén 7, 47011 Valladolid, Spain
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Li Y, Li Z, Zhang Z. Mechanism and regio- and stereoselectivity in NHC-catalyzed reaction of 2-bromoenals with β-ketoamides. MOLECULAR CATALYSIS 2021. [DOI: 10.1016/j.mcat.2021.111790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Li Y, Li Z, Zhang Z. Mechanism and regio- and stereoselectivity in an NHC-catalyzed Mannich/lactamization domino reaction. Phys Chem Chem Phys 2021; 23:6204-6212. [PMID: 33687420 DOI: 10.1039/d1cp00369k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Density functional theory (DFT) calculations (M06-2X) have been employed to disclose the mechanisms and regio- and stereo-selectivities of the N-heterocyclic carbene (NHC)-catalyzed reaction of 2-benzothiazolimines and α-chloroaldehydes. The preferred mechanism is initiated by the nucleophilic attack of NHC on α-chloroaldehyde (first step), followed by 1,2-proton transfer which was assisted by the Brønsted acid DABCO·H+ to generate the Breslow intermediate (second step). The cleavage of the C-Cl bond (third step) and deprotonation (fourth step) form the enolate intermediate. This further reacts with 2-benzothiazolimine which leads to the formation of a new C-C bond (fifth step). Subsequent cyclization takes place via the formation of a new C-N bond (sixth step). Catalyst regeneration completes the whole catalytic cycle and affords the final product (seventh step). The DFT results indicate that the fifth step determines the stereochemistry of the reaction and leads to benzothiazolopyrimidinone with the SS configuration, which agrees well with experimental observations. Intramolecular cyclization is found to be the regioselectivity-determining step, for which the [4+2] annulation pathway is more preferred than that via [2+2] annulation, which again agrees well with experimental observations. Based on the mechanism proposed, the origins of regio- and stereoselectivities have also been investigated by performing distortion/interaction, natural bond orbital (NBO) and non-covalent interaction (NCI) analyses. The mechanistic insights gained in this work should be helpful in the rational design of potential catalysts for analogous reactions.
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Affiliation(s)
- Yan Li
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China.
| | - Zhilin Li
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China.
| | - Zhiqiang Zhang
- School of Chemical Engineering, University of Science and Technology Liaoning, Anshan 114051, P. R. China.
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Alves AJS, Alves NG, Soares MIL, Pinho e Melo TMVD. Strategies and methodologies for the construction of spiro-γ-lactams: an update. Org Chem Front 2021. [DOI: 10.1039/d0qo01564d] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This review gives an insight into the most recent synthetic methodologies towards spiro-γ-lactams, a class of compounds that are present in a wide range of synthetic bioactive and naturally occurring molecules.
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Affiliation(s)
- Américo J. S. Alves
- University of Coimbra
- Coimbra Chemistry Centre and Department of Chemistry
- 3004-535 Coimbra
- Portugal
| | - Nuno G. Alves
- University of Coimbra
- Coimbra Chemistry Centre and Department of Chemistry
- 3004-535 Coimbra
- Portugal
| | - Maria I. L. Soares
- University of Coimbra
- Coimbra Chemistry Centre and Department of Chemistry
- 3004-535 Coimbra
- Portugal
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Abstract
This review summaries recent synthetic developments towards spirocyclic oxindoles and applications as valuable medicinal and synthetic targets.
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Affiliation(s)
- Alexander J. Boddy
- Department of Chemistry
- Imperial College London
- Molecular Sciences Research Hub
- London W12 0BZ
- UK
| | - James A. Bull
- Department of Chemistry
- Imperial College London
- Molecular Sciences Research Hub
- London W12 0BZ
- UK
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Mechanisms and origins of stereoselectivity of NHC-catalyzed reaction of aldehyde and butadienoate. MOLECULAR CATALYSIS 2020. [DOI: 10.1016/j.mcat.2020.111030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Li Y, Zhang Z. Computational study on NHC catalyzed [4+2] annulation between γ-chloroenals and pyrazolinones: mechanism and stereoselectivity. NEW J CHEM 2020. [DOI: 10.1039/d0nj01499k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mechanisms and origins of stereoselectivity of NHC-catalyzed reaction between γ-chloroenal and α-arylidene pyrazolinone.
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Affiliation(s)
- Yan Li
- School of Chemical Engineering
- University of Science and Technology Liaoning
- Anshan 114051
- P. R. China
| | - Zhiqiang Zhang
- School of Chemical Engineering
- University of Science and Technology Liaoning
- Anshan 114051
- P. R. China
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Wang X, Zhang Y, Yang Y, Xue Y. The mechanism and diastereoselectivity in the formation of trifluoromethyl-containing spiro[pyrrolidin-3,2′-oxindole] by a catalyst-free and mutually activated [3+2]-cycloaddition reaction: a theoretical study. NEW J CHEM 2020. [DOI: 10.1039/d0nj04063k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The mechanism and diastereoselectivity of the [3+2] cycloaddition reaction between (Z)-1-methyl-3-imino-indolin-2-one and 5-nitro-2-vinylpyridine with no catalyst in acetonitrile have been investigated by the DFT method and SMD solvation model.
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Affiliation(s)
- Xingyu Wang
- College of Chemistry
- Key Lab of Green Chemistry and Technology in Ministry of Education
- Sichuan University
- Chengdu 610064
- People's Republic of China
| | - Yan Zhang
- College of Chemistry
- Key Lab of Green Chemistry and Technology in Ministry of Education
- Sichuan University
- Chengdu 610064
- People's Republic of China
| | - Yongsheng Yang
- College of Chemistry
- Key Lab of Green Chemistry and Technology in Ministry of Education
- Sichuan University
- Chengdu 610064
- People's Republic of China
| | - Ying Xue
- College of Chemistry
- Key Lab of Green Chemistry and Technology in Ministry of Education
- Sichuan University
- Chengdu 610064
- People's Republic of China
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