Copper(I)-Catalyzed Asymmetric α-Selenenylation of 2-Acylimidazoles.

Abstract

A general method for the catalytic asymmetric α-selenenylation of simple carbonyl compounds is lacking. Herein, a copper(I)-catalyzed enantioselective α-selenenylation of 2-acylimidazoles with electrophilic selenosulfonates is uncovered. The reaction enjoys the advantages of mild conditions, easy reaction protocol, and broad substrate scopes on both 2-acylimidazoles and selenosulfonates. Mechanistic studies reveal a pincer Cu(I)-(S,S)-Ph-BOPA complex as the active catalyst. Some traditional electrophilic selenenylation reagents, such as PhSeCl, PhSeSePh, and 2-(phenylselanyl)isoindoline-1,3-dione lead to inferior results in terms of both yield and enantioselectivity, highlighting the superiority of selenosulfonates. Finally, several transformations based on both the 2-acylimidazole group and the selenoether group are successfully carried out, demonstrating the synthetic utilities of the present methodology.