1
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Tang C, Cai H, Song C, Wang X, Jin Z, Li T. N-Heterocyclic Carbene-Catalyzed Regio- and Enantioselective C7-Alkylation of 4-Aminoindoles with α-Bromoenals. Org Lett 2024; 26:1787-1791. [PMID: 38393341 DOI: 10.1021/acs.orglett.3c04266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
The first carbene-catalyzed regio- and enantioselective indole C7-alkylation reaction between 4-aminoindoles and α-bromoenals is disclosed. The corresponding indole products could be obtained in moderate to good yields with good to excellent enantioselectivities. The evaluation of antibacterial activity against Psa revealed that nine of the C7-functionalized indoles exhibited superior inhibitory activities compared to the positive controls TC and BT. Our approach provides an efficient strategy to introduce a chiral chain into the C7 position of indole compounds, with potential applications evaluated in pesticide development.
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Affiliation(s)
- Chenghao Tang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, Guizhou 550025, China
- School of Life and Health Science, Kaili University, Kaili, Guizhou 556011, China
| | - Hui Cai
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, Guizhou 550025, China
| | - Chaoyang Song
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, Guizhou 550025, China
| | - Xiang Wang
- School of Life and Health Science, Kaili University, Kaili, Guizhou 556011, China
| | - Zhichao Jin
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, Guizhou 550025, China
| | - Tingting Li
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Center for R&D of Fine Chemicals of Guizhou University, Guiyang, Guizhou 550025, China
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2
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Tang C, Wang W, Luo G, Song C, Bao Z, Li P, Hao G, Chi YR, Jin Z. Carbene‐Catalyzed Activation of C−Si Bonds for Chemo‐ and Enantioselective Cross Brook–Benzoin Reaction. Angew Chem Int Ed Engl 2022; 61:e202206961. [DOI: 10.1002/anie.202206961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Indexed: 01/06/2023]
Affiliation(s)
- Chenghao Tang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
- School of Life and Health Science Kaili University Kaili 556011 China
| | - Wei Wang
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
| | - Guoyong Luo
- School of Pharmacy Guizhou University of Traditional Chinese Medicine Guiyang 550025 China
| | - Chaoyang Song
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
| | - Zhaowei Bao
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
| | - Pei Li
- School of Life and Health Science Kaili University Kaili 556011 China
| | - Gefei Hao
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
| | - Yonggui Robin Chi
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
- Division of Chemistry & Biological Chemistry School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Zhichao Jin
- State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Guiyang 550025 China
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3
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Tang C, Wang W, Luo G, Song C, Bao Z, Li P, Hao G, Chi YR, Jin Z. Carbene‐Catalyzed Activation of C‐Si Bonds for Chemo‐ and Enantioselective Cross Brook‐Benzoin Reaction. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Wei Wang
- Guizhou University Chemistry CHINA
| | - Guoyong Luo
- Guizhou University Of Traditional Chinese Medicine Chemistry CHINA
| | | | | | - Pei Li
- Kaili University Chemistry CHINA
| | | | - Yonggui Robin Chi
- Nanyang Technological University Division of Chemistry and Biological Chemistry SINGAPORE
| | - Zhichao Jin
- Guizhou University Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Huaxi District 550025 Guiyang CHINA
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4
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Zhen G, Jiang K, Yin B. Progress in Organocatalytic Dearomatization Reactions Catalyzed by Heterocyclic Carbenes. ChemCatChem 2022. [DOI: 10.1002/cctc.202200099] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Guangjin Zhen
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Kai Jiang
- South China University of Technology School of Chemistry and Chemical Engineering CHINA
| | - Biaolin Yin
- South China University of Technology Dept. of Chenistry and chemical engineering Wushan Street 510640 Guangzhou CHINA
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5
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Zhu J, Moreno I, Quinn P, Yufit DS, Song L, Young CM, Duan Z, Tyler AR, Waddell PG, Hall MJ, Probert MR, Smith AD, O'Donoghue AC. The Role of the Fused Ring in Bicyclic Triazolium Organocatalysts: Kinetic, X-ray, and DFT Insights. J Org Chem 2022; 87:4241-4253. [PMID: 35230109 PMCID: PMC8938951 DOI: 10.1021/acs.joc.1c03073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Bicyclic triazolium
scaffolds are widely employed in N-heterocyclic carbene
(NHC) organocatalysis. While the incorporation
of a fused ring was initially for synthetic utility in accessing chiral,
modular triazolyl scaffolds, recent results highlight the potential
for impact upon reaction outcome with the underpinning origins unclear.
The common first step to all triazolium-catalyzed transformations
is C(3)-H deprotonation to form the triazolylidene NHC. Herein, we
report an analysis of the impact of size of the fused (5-, 6-, and
7-membered, n = 1, 2, and 3, respectively) ring on
the C(3) proton transfer reactions of a series of bicyclic triazolium
salts. Rate constants for the deuteroxide-catalyzed C(3)-H/D-exchange
of triazolium salts, kDO, were significantly
influenced by the size of the adjacent fused ring, with the kinetic
acidity trend, or protofugalities, following the order kDO (n = 1) > kDO (n = 2) ≈ kDO (n = 3). Detailed analyses of X-ray diffraction
(XRD) data for 20 triazolium salts (including 16 new structures) and
of computational data for the corresponding triazolylidene NHCs provide
insight on structural effects of alteration of fused ring size. In
particular, changes in internal triazolyl NCN angle and positioning
of the most proximal CH2 with variation in fused ring size
are proposed to influence the experimental protofugality order.
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Affiliation(s)
- Jiayun Zhu
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Inmaculada Moreno
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K.,Dpto. de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla - La Mancha, Avda. Camilo José Cela s/N, 13071 Ciudad Real, Spain
| | - Peter Quinn
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Dmitry S Yufit
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, U.K
| | - Lijuan Song
- School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China
| | - Claire M Young
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
| | - Zhuan Duan
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
| | - Andrew R Tyler
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Paul G Waddell
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Michael J Hall
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Michael R Probert
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, U.K
| | - Andrew D Smith
- EaStCHEM, School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, U.K
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6
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Triazolium Salt Organocatalysis: Mechanistic Evaluation of Unusual Ortho-Substituent Effects on Deprotonation. Catalysts 2021. [DOI: 10.3390/catal11091055] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Organocatalysis by N-heterocyclic carbenes is normally initiated by the deprotonation of precursor azolium ions to form active nucleophilic species. Substituent effects on deprotonation have an impact on catalytic efficiency and provide insight into general catalytic mechanisms by commonly used azolium systems. Using an NMR kinetic method for the analysis of C(3)-H/D exchange, we determined log kex–pD profiles for three ortho-substituted N-aryl triazolium salts, which enables a detailed analysis of ortho-substituent effects on deprotonation. This includes N-5-methoxypyrid-2-yl triazolium salt 7 and di-ortho-methoxy and di-ortho-isopropoxyphenyl triazolium salts 8 and 9, and we acquired additional kinetic data to supplement our previously published analysis of N-pyrid-2-yl triazolium salt 6. For 2-pyridyl triazoliums 6 and 7, novel acid catalysis of C(3)-H/D exchange is observed under acidic conditions. These kinetic data were supplemented by DFT analyses of the conformational preferences of 6 upon N-protonation. A C(3) deprotonation mechanism involving intramolecular general base deprotonation by the pyridyl nitrogen of the N(1)-deuterated dicationic triazolium salt is most consistent with the data. We also report kDO values (protofugalities) for deuteroxide-catalyzed exchange for 6–9. The protofugalities for 8 and 9 are the lowest values to date in the N-aryl triazolium series.
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7
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Yang X, Majhi PK, Chai H, Liu B, Sun J, Liu T, Liu Y, Zhou L, Xu J, Liu J, Wang D, Zhao Y, Jin Z, Chi YR. Carbene-Catalyzed Enantioselective Aldol Reaction: Post-Aldol Stereochemistry Control and Formation of Quaternary Stereogenic Centers. Angew Chem Int Ed Engl 2021; 60:159-165. [PMID: 32931603 DOI: 10.1002/anie.202008369] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/28/2020] [Indexed: 12/13/2022]
Abstract
The dominated approaches for asymmetric aldol reactions have primarily focused on the aldol carbon-carbon bond-forming events. Here we postulate and develop a new catalytic strategy that seeks to modulate the reaction thermodynamics and control the product enantioselectivities via post-aldol processes. Specifically, an NHC catalyst is used to activate a masked enolate substrate (vinyl carbonate) to promote the aldol reaction in a non-enantioselective manner. This reversible aldol event is subsequently followed by an enantioselective acylative kinetic resolution that is mediated by the same (chiral) NHC catalyst without introducing any additional substance. This post-aldol process takes care of the enantioselectivity issues and drives the otherwise reversible aldol reaction toward a complete conversion. The acylated aldol products bearing quaternary/tetrasubstituted carbon stereogenic centers are formed in good yields and high optical purities.
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Affiliation(s)
- Xing Yang
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Pankaj Kumar Majhi
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Huifang Chai
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, China
| | - Bin Liu
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, China
| | - Jun Sun
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, China
| | - Ting Liu
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, China
| | - Yonggui Liu
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, China
| | - Liejin Zhou
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Jun Xu
- Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, China
| | - Jiawei Liu
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Dongdong Wang
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Yanli Zhao
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Zhichao Jin
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, China
| | - Yonggui Robin Chi
- Division of Chemistry & Mathematical Science, School of Physical & Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore.,Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang, 550025, China
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8
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Yang X, Majhi PK, Chai H, Liu B, Sun J, Liu T, Liu Y, Zhou L, Xu J, Liu J, Wang D, Zhao Y, Jin Z, Chi YR. Carbene‐Catalyzed Enantioselective Aldol Reaction: Post‐Aldol Stereochemistry Control and Formation of Quaternary Stereogenic Centers. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202008369] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Xing Yang
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Pankaj Kumar Majhi
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Huifang Chai
- Guizhou University of Traditional Chinese Medicine Guiyang 550025 China
| | - Bin Liu
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Huaxi District Guiyang 550025 China
| | - Jun Sun
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Huaxi District Guiyang 550025 China
| | - Ting Liu
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Huaxi District Guiyang 550025 China
| | - Yonggui Liu
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Huaxi District Guiyang 550025 China
| | - Liejin Zhou
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Jun Xu
- Guizhou University of Traditional Chinese Medicine Guiyang 550025 China
| | - Jiawei Liu
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Dongdong Wang
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Yanli Zhao
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
| | - Zhichao Jin
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Huaxi District Guiyang 550025 China
| | - Yonggui Robin Chi
- Division of Chemistry & Mathematical Science School of Physical & Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
- Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural Bioengineering Ministry of Education Guizhou University Huaxi District Guiyang 550025 China
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9
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Wang M, Zhou M, Zhang L, Zhang Z, Zhang W. A step-economic and one-pot access to chiral C α-tetrasubstituted α-amino acid derivatives via a bicyclic imidazole-catalyzed direct enantioselective C-acylation. Chem Sci 2020; 11:4801-4807. [PMID: 34122937 PMCID: PMC8159231 DOI: 10.1039/d0sc00808g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Cα-Tetrasubstituted α-amino acids are ubiquitous and unique structural units in bioactive natural products and pharmaceutical compounds. The asymmetric synthesis of these molecules has attracted a lot of attention, but a more efficient method is still greatly desired. Here we describe the first sequential four-step acylation reaction for the efficient synthesis of chiral Cα-tetrasubstituted α-amino acid derivatives from simple N-acylated amino acids via an auto-tandem catalysis using a single nucleophilic catalyst. The synthetic efficiency is improved via a direct enantioselective C-acylation; the methodology affords the corresponding Cα-tetrasubstituted α-amino acid derivatives with excellent enantioselectivities (up to 99% ee). This step-economic, one-pot, and auto-tandem strategy provides facile access to important chiral building blocks, such as peptides, serines, and oxazolines, which are often used in medicinal and synthetic chemistry. The first four-step sequential reaction for the synthesis of Cα-tetrasubstituted chiral α-amino acid derivatives via auto-tandem catalysis has been developed.![]()
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Affiliation(s)
- Mo Wang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University Shanghai 200240 China .,School of Pharmacy, Shanghai Jiao Tong University Shanghai 200240 China
| | - Muxing Zhou
- School of Pharmacy, Shanghai Jiao Tong University Shanghai 200240 China
| | - Lu Zhang
- School of Pharmacy, Shanghai Jiao Tong University Shanghai 200240 China
| | - Zhenfeng Zhang
- School of Pharmacy, Shanghai Jiao Tong University Shanghai 200240 China
| | - Wanbin Zhang
- Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Frontiers Science Center for Transformative Molecules, Shanghai Jiao Tong University Shanghai 200240 China .,School of Pharmacy, Shanghai Jiao Tong University Shanghai 200240 China
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10
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Cativiela C, Ordóñez M, Viveros-Ceballos JL. Stereoselective synthesis of acyclic α,α-disubstituted α-amino acids derivatives from amino acids templates. Tetrahedron 2020. [DOI: 10.1016/j.tet.2019.130875] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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11
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Reddy GR, Avadhani AS, Rajaram S. Activation of Benzyl Aryl Carbonates: The Role of Cation-π Interactions. J Org Chem 2016; 81:4134-41. [PMID: 27158833 DOI: 10.1021/acs.joc.6b00441] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Benzyl aryl carbonates can react with a nucleophile to yield an activated electrophile and an aryloxide anion. Previously, we had utilized this in the synthesis of α-nitro esters from nitroalkanes. To further understand the process of activation of these carbonates by nucleophiles, we have performed kinetic studies on the hydrolysis of carbonates using nucleophiles. Rate constants for the hydrolysis were obtained under pseudo-first-order conditions with DABCO as the nucleophile. A comparison of rate constant for hydrolysis of isobutyl phenyl carbonate with benzyl phenyl carbonate shows that the presence of benzyl group results in a 16-fold acceleration of hydrolysis rate. This indicates that the transition state for activation of carbonate is stabilized by cation-π interactions. A comparison of the rate constant for various aromatic rings indicates that electron-donating substituents on the benzyl groups accelerate the rate of hydrolysis. Studies were also carried out with DMAP as nucleophile and the results are presented. Our studies show that stable carbonates can be activated using nucleophiles. Activated acyl groups generated from acid anhydrides have been used in several enantioselective reactions. Our studies show that carbonates can be stable alternatives to acid anhydrides.
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Affiliation(s)
- Golipalli Ramana Reddy
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur P.O., Bangalore 560064, India
| | - Anusha S Avadhani
- New Chemistry Unit, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur P.O., Bangalore 560064, India
| | - Sridhar Rajaram
- International Centre for Materials Science, Jawaharlal Nehru Centre for Advanced Scientific Research , Jakkur P.O., Bangalore 560064, India
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12
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Vasiloiu M, Cervenka I, Gaertner P, Weil M, Schröder C, Bica K. Amino alcohol-derived chiral ionic liquids: structural investigations toward chiral recognition. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.tetasy.2015.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Campbell CD, Joannesse C, Morrill LC, Philp D, Smith AD. Regiodivergent Lewis base-promoted O- to C-carboxyl transfer of furanyl carbonates. Org Biomol Chem 2015; 13:2895-900. [DOI: 10.1039/c4ob02629b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Triazolinylidenes promote γ-selective C-carboxylation (up to 99 : 1 regioselectivity) in the O- to C-carboxyl transfer of furanyl carbonates in contrast to DMAP that promotes preferential α-C-carboxylation with moderate regiocontrol (typically 60 : 40 regioselectivity).
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Affiliation(s)
| | | | | | - Douglas Philp
- EaStCHEM
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
| | - Andrew D. Smith
- EaStCHEM
- School of Chemistry
- University of St Andrews
- St Andrews
- UK
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14
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Gould E, Walden DM, Kasten K, Johnston RC, Wu J, Slawin AMZ, Mustard TJL, Johnston B, Davies T, Ha-Yeon Cheong P, Smith AD. Catalyst selective and regiodivergent O- to C- or N-carboxyl transfer of pyrazolyl carbonates: synthetic and computational studies. Chem Sci 2014. [DOI: 10.1039/c4sc00879k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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15
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Rey YP, Gilmour R. Modulating NHC catalysis with fluorine. Beilstein J Org Chem 2013; 9:2812-20. [PMID: 24367445 PMCID: PMC3869272 DOI: 10.3762/bjoc.9.316] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 11/08/2013] [Indexed: 11/23/2022] Open
Abstract
Fluorination often confers a range of advantages in modulating the conformation and reactivity of small molecule organocatalysts. By strategically introducing fluorine substituents, as part of a β-fluoroamine motif, in a triazolium pre-catalyst, it was possible to modulate the behaviour of the corresponding N-heterocyclic carbene (NHC) with minimal steric alterations to the catalyst core. In this study, the effect of hydrogen to fluorine substitution was evaluated as part of a molecular editing study. X-ray crystallographic analyses of a number of derivatives are presented and the conformations are discussed. Upon deprotonation, the fluorinated triazolium salts generate catalytically active N-heterocyclic carbenes, which can then participate in the enantioselective Steglich rearrangement of oxazolyl carbonates to C-carboxyazlactones (e.r. up to 87.0:13.0).
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Affiliation(s)
- Yannick P Rey
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
- Department of Chemistry and Applied Biosciences, ETH Zürich, Wolfgang-Pauli-Str. 10, 8093 Zürich, Switzerland
| | - Ryan Gilmour
- Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster, Germany
- Excellence Cluster EXC 1003, Cells in Motion, Münster, Germany
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16
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Li N, Tu MS, Jiang B, Wang X, Tu SJ. Domino [3+2+1] heterocyclization of isothiocyanates with aryl amidines leading to polysubstituted 1,3,5-triazine derivatives. Tetrahedron Lett 2013. [DOI: 10.1016/j.tetlet.2013.01.086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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17
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Leckie SM, Brown TB, Pryde D, Lebl T, Slawin AMZ, Smith AD. NHC-mediated enantioselective formal [4 + 2] cycloadditions of alkylarylketenes and β,γ-unsaturated α-ketocarboxylic esters and amides. Org Biomol Chem 2013; 11:3230-46. [DOI: 10.1039/c3ob40424b] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Chen X, Fang X, Chi YR. cis-Enals in N-heterocyclic carbene-catalyzed reactions: distinct stereoselectivity and reactivity. Chem Sci 2013. [DOI: 10.1039/c3sc50666e] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Collett CJ, Massey RS, Maguire OR, Batsanov AS, O'Donoghue AC, Smith AD. Mechanistic insights into the triazolylidene-catalysed Stetter and benzoin reactions: role of the N-aryl substituent. Chem Sci 2013. [DOI: 10.1039/c2sc22137c] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Morrill LC, Douglas J, Lebl T, Slawin AMZ, Fox DJ, Smith AD. Isothiourea-mediated asymmetric Michael-lactonisation of trifluoromethylenones: a synthetic and mechanistic study. Chem Sci 2013. [DOI: 10.1039/c3sc51791h] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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Massey RS, Collett CJ, Lindsay AG, Smith AD, O’Donoghue AC. Proton Transfer Reactions of Triazol-3-ylidenes: Kinetic Acidities and Carbon Acid pKa Values for Twenty Triazolium Salts in Aqueous Solution. J Am Chem Soc 2012; 134:20421-32. [DOI: 10.1021/ja308420c] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Richard S. Massey
- Department of Chemistry, Durham University, University Science Laboratories,
South Road, Durham DH1 3LE, U.K
| | - Christopher J. Collett
- EaStCHEM, School
of Chemistry, University of St. Andrews, North Haugh, St. Andrews KY16 9ST, U.K
| | - Anita G. Lindsay
- Department of Chemistry, Durham University, University Science Laboratories,
South Road, Durham DH1 3LE, U.K
| | - Andrew D. Smith
- EaStCHEM, School
of Chemistry, University of St. Andrews, North Haugh, St. Andrews KY16 9ST, U.K
| | - AnnMarie C. O’Donoghue
- Department of Chemistry, Durham University, University Science Laboratories,
South Road, Durham DH1 3LE, U.K
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Xue LY, Jiang B, Tu MS, Tu SJ. A new and efficient domino strategy to indole derivatives synthesis and its C3-bisfunctionalization. Tetrahedron Lett 2012. [DOI: 10.1016/j.tetlet.2012.09.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Joannesse C, Johnston CP, Morrill LC, Woods PA, Kieffer M, Nigst TA, Mayr H, Lebl T, Philp D, Bragg RA, Smith AD. Isothiourea-Mediated Asymmetric O- to C-Carboxyl Transfer of Oxazolyl Carbonates: Structure-Selectivity Profiles and Mechanistic Studies. Chemistry 2012; 18:2398-408. [DOI: 10.1002/chem.201102847] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Indexed: 11/07/2022]
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Li G, Tu SJ, Dai AX, Yi MS, Jiang B, Wang Q. Highly Stereoselective Synthesis of anti-Tetrahydropyrimidine Derivatives under Microwave Heating. HETEROCYCLES 2012. [DOI: 10.3987/com-12-s(n)40] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Franz JF, Fuchs PJ, Zeitler K. A versatile combined N-heterocyclic carbene and base-catalyzed multiple cascade approach for the synthesis of functionalized benzofuran-3-(2H)-ones. Tetrahedron Lett 2011. [DOI: 10.1016/j.tetlet.2011.10.078] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Woods PA, Morrill LC, Bragg RA, Smith AD. Isothiourea-Catalysed Asymmetric C-Acylation of Silyl Ketene Acetals. Chemistry 2011; 17:11060-7. [DOI: 10.1002/chem.201100995] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 05/31/2011] [Indexed: 11/07/2022]
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