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Leung VMY, Pook CM, Chan TC, Yeung YY. Trialkylphosphonium Oxoborate as C(sp 3 )-H Oxyanion Hole Catalyst for Diels-Alder Reaction. Chem Asian J 2024; 19:e202300981. [PMID: 38116878 DOI: 10.1002/asia.202300981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/19/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023]
Abstract
We have developed a catalytic protocol for Diels-Alder reaction using trialkylphosphonium oxoborates as oxyanion hole catalysts. The reaction can be operated under ambient conditions. Dienes could easily polymerize under acidic condition. Nonetheless, these acid-sensitive substrates are compatible with the catalytic protocol and the reaction scope covers a wide range of substrates.
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Affiliation(s)
- Vincent Ming-Yau Leung
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT, Hong Kong, China
| | - Chun-Man Pook
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT, Hong Kong, China
| | - Tsz-Chun Chan
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT, Hong Kong, China
| | - Ying-Yeung Yeung
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT, Hong Kong, China
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Leung VMY, Wong HCF, Pook CM, Tse YLS, Yeung YY. Trialkylphosphonium oxoborates as C(sp 3)-H oxyanion holes and their application in catalytic chemoselective acetalization. Chem Sci 2023; 14:12684-12692. [PMID: 38020391 PMCID: PMC10646966 DOI: 10.1039/d3sc03081d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/15/2023] [Indexed: 12/01/2023] Open
Abstract
The use of trialkylphosphonium oxoborates (TOB) as catalysts is reported. The site-isolated borate counter anion in a TOB catalyst increases the availability of C(sp3)-H to interact with electron donor substrates. The catalytic protocol is applicable to a wide range of substrates in the acetalization reaction and provides excellent chemoselectivity in the acetalization over thioacetalization in the presence of alcohols and thiols, which is otherwise hard to achieve using typical acid catalysts. Experimental and computational studies revealed that the TOB catalysts have multiple preorganized C(sp3)-Hs that serve as a mimic of oxyanion holes, which can stabilize the oxyanion intermediates via multiple C(sp3)-H non-classical hydrogen bond interactions.
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Affiliation(s)
- Vincent Ming-Yau Leung
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT Hong Kong China
| | - Hong-Chai Fabio Wong
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT Hong Kong China
| | - Chun-Man Pook
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT Hong Kong China
| | - Ying-Lung Steve Tse
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT Hong Kong China
| | - Ying-Yeung Yeung
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong Shatin, NT Hong Kong China
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Qiang S, Hu R, Yeung Y. Zwitterion‐Catalyzed Ring‐Opening of Epoxides with Carboxylic Acids. ASIAN J ORG CHEM 2023. [DOI: 10.1002/ajoc.202200673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Shengsheng Qiang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong Kong Shatin, NT Hong Kong P. R. China
| | - Rong‐Bin Hu
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong Kong Shatin, NT Hong Kong P. R. China
| | - Ying‐Yeung Yeung
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry The Chinese University of Hong Kong Shatin, NT Hong Kong P. R. China
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Li Q, Zhang W, Zhu C, Pan H, Shi KY, Zhang Y, Han MY, Tan CH. Organobase-Catalyzed Umpolung of Amides: The Generation and Transfer of Carbamoyl Anion. J Org Chem 2023; 88:1245-1255. [PMID: 36628963 DOI: 10.1021/acs.joc.2c02487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A novel organobase-catalyzed umpolung reaction of amides was disclosed. This method provides an efficient method to generate and transfer carbamoyl anions. In this transformation, some of the inherent disadvantages of carbamoyl metal were avoided. The mechanistic analysis revealed that the reaction proceeds through polarity inversion of amide, and various carbamoyl anions were applied in the reaction. Moreover, a wide range of substrates was achieved with moderate to excellent yield.
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Affiliation(s)
- Qi Li
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Wang Zhang
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Chen Zhu
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Hong Pan
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Kang-Yue Shi
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Yicheng Zhang
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Man-Yi Han
- Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huabei Normal University, Huaibei, Anhui 235000, PR China
| | - Choon-Hong Tan
- Division of Chemistry and Biological Chemistry, Nanyang Technological University, Singapore 637371
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Hu RB, Qiang S, Chan YY, Huang J, Xu T, Yeung YY. Access to Bromo-γ-butenolides via Zwitterion-Catalyzed Rearrangement of Cyclopropene Carboxylic Acids. Org Lett 2021; 23:9533-9537. [PMID: 34854693 DOI: 10.1021/acs.orglett.1c03751] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
γ-Butenolides are useful structural motifs in many pharmaceutically relevant compounds. In particular, halogenated γ-butenolides are attractive building blocks because the halogen handles can readily be manipulated to give various functional molecules. In this study, a catalytic synthesis of halogenated γ-butenolides from cyclopropene carboxylic acids was developed using zwitterionic catalysts and N-haloamides as the halogen sources. The catalytic protocol could also be applied to the synthesis of halogenated pyrrolones by using cyclopropene amides as the starting materials.
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Affiliation(s)
- Rong-Bin Hu
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Shengsheng Qiang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Yung-Yin Chan
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Jingxian Huang
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Tianyue Xu
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | - Ying-Yeung Yeung
- Department of Chemistry and State Key Laboratory of Synthetic Chemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong
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