Tandem Photoredox-Chiral Phosphoric Acid Catalyzed Radical-Radical Cross-Coupling for Enantioselective Synthesis of
Yang Zhang1, Dan Ye1, Lei Shen1
1Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Provincial Center for Research & Development of Natural Products, School of Chemical Science and Technology, Yunnan University, Kunming 650091, China.
Abstract:
A photochemical protocol that couples diarylamines and α-ketoesters to afford the chiral 3-hydroxyoxindoles through tandem photoredox and chiral phosphoric acid catalysis is developed. The reaction involves an enantioselective photochemical radical-radical cross-coupling process. The chiral phosphoric acid is discovered to play crucial roles by decreasing the reductive potentials of α-ketoesters and stereocontrolling the downstream asymmetric radical-radical cross-coupling via the formation of pentacoordinate complex.
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