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Xie C, Kim J, Mai BK, Cao S, Ye R, Wang XY, Liu P, Kwon O. Enantioselective Synthesis of Quaternary Oxindoles: Desymmetrizing Staudinger-Aza-Wittig Reaction Enabled by a Bespoke HypPhos Oxide Catalyst. J Am Chem Soc 2022; 144:21318-21327. [PMID: 36375169 PMCID: PMC10746329 DOI: 10.1021/jacs.2c09421] [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] [Indexed: 11/16/2022]
Abstract
This paper describes a catalytic asymmetric Staudinger-aza-Wittig reaction of (o-azidoaryl)malonates, allowing access to chiral quaternary oxindoles through phosphine oxide catalysis. We designed a novel HypPhos oxide catalyst to enable the desymmetrizing Staudinger-aza-Wittig reaction through the PIII/PV═O redox cycle in the presence of a silane reductant and an IrI-based Lewis acid. The reaction occurs under mild conditions, with good functional group tolerance, a wide substrate scope, and excellent enantioselectivity. Density functional theory revealed that the enantioselectivity in the desymmetrizing reaction arose from the cooperative effects of the IrI species and the HypPhos catalyst. The utility of this methodology is demonstrated by the (formal) syntheses of seven alkaloid targets: (-)-gliocladin C, (-)-coerulescine, (-)-horsfiline, (+)-deoxyeseroline, (+)-esermethole, (+)-physostigmine, and (+)-physovenine.
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Affiliation(s)
- Changmin Xie
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
| | - Jacob Kim
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
| | - Binh Khanh Mai
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
| | - Shixuan Cao
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
| | - Rong Ye
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
| | - Xin-Yi Wang
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
| | - Peng Liu
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Ohyun Kwon
- Department of Chemistry and Biochemistry, University of California─Los Angeles, 607 Charles E. Young Dr. East, Los Angeles, California 90095-1569, United States
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Chisholm DT, Hayes PG. Synthesis and characterization of group 13 dichloride (M = Ga, In), dimethyl (M = Al) and cationic methyl aluminum complexes supported by monoanionic NNN-pincer ligands. NEW J CHEM 2021. [DOI: 10.1039/d1nj01064f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of monoanionic NNN-pincer ligands effectively stabilize five-coordinate gallium and indium dichloride complexes, as well as neutral dimethyl aluminum species, and organometallic cations thereof.
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Affiliation(s)
- Desmond T. Chisholm
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4
| | - Paul G. Hayes
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive, Lethbridge, AB, Canada T1K 3M4
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