Dual Photoredox/Palladium Catalysis Enabled Enantioselective Heck/Reductive Allylic Homocoupling Reaction
Weiwei Zi1, Ruiyuan Zhang1, Hongfa Wang1,2
1State Key Laboratory and Institute of Elemento-Organic Chemistry, Frontiers Science Center for New Organic Matter, College of Chemistry, Nankai University, Tianjin, 300071, China.
Abstract:
The merger of palladium-catalyzed Tsuji-Trost reactions with photochemical radical chemistry represents a cutting-edge field in transition metal catalysis. We report a photochemical palladium-catalyzed enantioselective Heck/reductive allylic homocoupling reaction of 1,3-dienes. The transformation has a wide substrate scope and good functional group tolerance, providing a platform to synthesize optically pure chiral 1,5-dienes bearing 1,8-stereocenters. The reaction initiates with a Heck-type addition to generate a π-allyl-PdII species, followed by a photoredox process or ligand-to-metal charge transfer (LMCT) to generate an allylic radical, which undergoes homocoupling to give the final product.
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