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Published on: June 21, 2017
Iridium-Catalyzed Asymmetric Allylic Benzylation with Photogenerated Hydroxy-o-Quinodimethanes
Pusu Yang1, Rui-Xiang Wang1, Yuan-Zheng Cheng1
1State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai, 200032, China.
Abstract:
An iridium-catalyzed asymmetric allylic benzylation of aryl vinyl carbinols under light irradiation is described. 2-Methylbenzophenone derivatives are employed and activated to hydroxy-o-quinodimethanes by an ultraviolet (UV) light. This approach enables asymmetric allylic benzylation with high enantioselectivity (up to 99 % ee) from readily available 2-methylbenzophenones without the utilization of strong bases, and pre-activation or pre-functionalization of the substrates. Moreover, deuterium experiments reveal the generation of nucleophilic benzyl species from 2-methylbenzophenone under UV irradiation.
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