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Xu Y, Liu D, Gao F, Li S, Zhang X, Wang L, Yang D. Harnessing Dpp-Imine as a Powerful Achiral Cocatalyst to Dramatically Increase the Efficiency and Stereoselectivity in a Magnesium-Mediated Oxa-Michael Reaction. JACS AU 2024; 4:164-176. [PMID: 38274262 PMCID: PMC10806778 DOI: 10.1021/jacsau.3c00584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/06/2023] [Accepted: 12/11/2023] [Indexed: 01/27/2024]
Abstract
Dpp-imines are classic model substrates for synthetic method studies. Here, we disclose their powerful use as achiral coligands in metal-catalyzed reactions. It is highly interesting to find that the Dpp-imine can not only act as powerful ligand to create excellent chiral pockets with magnesium complexes but also, more importantly, this coligand can dramatically enhance the catalytic ability of the metal catalyst. The underlying reaction mechanism was extensively explored by conducting a series of experiments, including 31P NMR studies of the coordination complex between the Dpp-imine coligand and magnesium complexes, ESI capture results, multiple control experiments, studies and comparison of different coligands, 1H NMR studies on the relationship between the substrate and Dpp-imine coligand, as well as the relationship between the substrate and the full complexes. Furthermore, DFT calculation provided valuable insights in the role of the imine additive and demonstrated that adding the Dpp-imine coligand in the magnesium catalyst can switch the deprotonation/nucleophilic addition steps from a stepwise mechanism to a concerted process during the oxa-cyclization reaction. The crucial factors responsible for the excellent enantioselectivity and enhanced reaction efficiency brought by Dpp-imine have been extracted from the calculation model. These mechanistic experiments and DFT calculation data clearly disclose and prove the powerful and interesting functions of the Dpp-imine coligand, which also direct a novel application of this type of active imine as useful ligands in metal-catalyzed asymmetric reactions.
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Affiliation(s)
- Yingfan Xu
- Key
Laboratory of Preclinical Study for New Drugs of Gansu Province, School
of Basic Medical Sciences & Research Unit of Peptide Science,
2019RU066, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Dan Liu
- Institute
of Systems and Physical Biology, Shenzhen
Bay Laboratory, Shenzhen 518055, P. R. China
| | - Feiyun Gao
- Key
Laboratory of Preclinical Study for New Drugs of Gansu Province, School
of Basic Medical Sciences & Research Unit of Peptide Science,
2019RU066, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Shixin Li
- Key
Laboratory of Preclinical Study for New Drugs of Gansu Province, School
of Basic Medical Sciences & Research Unit of Peptide Science,
2019RU066, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Xiaoyong Zhang
- Institute
of Systems and Physical Biology, Shenzhen
Bay Laboratory, Shenzhen 518055, P. R. China
| | - Linqing Wang
- Key
Laboratory of Preclinical Study for New Drugs of Gansu Province, School
of Basic Medical Sciences & Research Unit of Peptide Science,
2019RU066, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
| | - Dongxu Yang
- Key
Laboratory of Preclinical Study for New Drugs of Gansu Province, School
of Basic Medical Sciences & Research Unit of Peptide Science,
2019RU066, Lanzhou University, Lanzhou 730000, Gansu, P. R. China
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Liu X, Zhu F, Ajitha MJ, Zhang Y, Huang KW, Li D, Wang D. Organocatalyzed Enantioselective [2 + 2] Cycloaddition of C, N-Cyclic Ketimines and Allenoates. Org Lett 2024; 26:225-230. [PMID: 38147459 DOI: 10.1021/acs.orglett.3c03848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
We report a novel enantioselective and regioselective [2 + 2] cycloaddition of allenoate and C,N-cyclic ketimine catalyzed by a quinidine derivative. The methodology enables the synthesis of fused tricyclic azetidines with a quaternary stereogenic center exhibiting high enantioselectivities. The broad range of substrates demonstrates the generality of the protocol, and the resulting functional products can be easily converted to a variety of valuable synthons. To elucidate the plausible reaction mechanism and how the catalyst affects absolute stereocontrol over the products, we conducted the corresponding density functional theory (DFT) calculations.
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Affiliation(s)
- Xinyu Liu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266100, China
| | - Fangfang Zhu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266100, China
| | - Manjaly J Ajitha
- KAUST Catalysis Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Yunfeng Zhang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266100, China
| | - Kuo-Wei Huang
- KAUST Catalysis Center, Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Dehai Li
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266100, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao, Shandong 266237, China
| | - De Wang
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao, Shandong 266100, China
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, 1 Wenhai Road, Qingdao, Shandong 266237, China
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Wang Q, Wu S, Zou J, Liang X, Mou C, Zheng P, Chi YR. NHC-catalyzed enantioselective access to β-cyano carboxylic esters via in situ substrate alternation and release. Nat Commun 2023; 14:4878. [PMID: 37573355 PMCID: PMC10423276 DOI: 10.1038/s41467-023-40645-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 08/04/2023] [Indexed: 08/14/2023] Open
Abstract
A carbene-catalyzed asymmetric access to chiral β-cyano carboxylic esters is disclosed. The reaction proceeds between β,β-disubstituted enals and aromatic thiols involving enantioselective protonation of enal β-carbon. Two main factors contribute to the success of this reaction. One involves in situ ultrafast addition of the aromatic thiol substrates to the carbon-carbon double bond of the enal substrate. This reaction converts almost all enal substrate to a Thiol-click Intermediate, significantly reducing aromatic thiol substrates concentration and suppressing the homo-coupling reaction of enals. Another factor is an in situ release of enal substrate from the Thiol-click Intermediate for the desired reaction to proceed effectively. The optically enriched β-cyano carboxylic esters from our method can be readily transformed to medicines that include γ-aminobutyric acids derivatives such as Rolipram. In addition to synthetic utilities, our control of reaction outcomes via in situ substrate modulation and release can likely inspire future reaction development.
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Affiliation(s)
- Qingyun Wang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, 550025, China
| | - Shuquan Wu
- Center for Industrial Catalysis and Cleaning Process Development, School of Chemical Engineering, Guizhou Minzu University, Guiyang, 550025, China
| | - Juan Zou
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, China
| | - Xuyang Liang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, 550025, China
| | - Chengli Mou
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, 550025, China
| | - Pengcheng Zheng
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, 550025, China.
| | - Yonggui Robin Chi
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Guiyang, 550025, China.
- School of Chemistry, Chemical Engineering, and Biotechnology, Nanyang Technological University, Singapore, 637371, Singapore.
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