Perfluoroarene Interaction-Controlled Chiral Phosphoric Acid-Catalyzed Enantioselective Michael Addition of Difluoroenoxysilanes to Azadienes: a Combination of Experimental and Theoretical Studies
Jinshan Li, Haohua Chen, Rong Zhong, Lei Zhu, Saimei Liu, Hanfeng Ding, Jianguo Yang, Lei Wang, Yu Lan, Zhiming Wang
Abstract
A catalytic and highly enantioselective Mukaiyama–Michael addition of difluoroenoxysilanes to azadienes has been developed using perfluorinated aryl-incorporating chiral monophosphoric acid (PF-CPA) as an effective, multipoint-controlled chiral catalyst. The inherent perfluoroaryl substituent is finely beneficial not only for achieving high catalytic activity but also for creating a compact and confined chiral environment for highly enantioselective transformations. Theoretical studies showed that the π–π interaction and hydrogen bond between PF-CPA and substrates play a crucial role in determining the stereochemical outcomes in comparison with those of phenyl, binaphthyl, and partially fluorinated aryls.