PdII -Catalyzed Regio- and Enantioselective Oxidative C-H/C-H Cross-Coupling Reaction between Ferrocenes and Azoles.

Abstract

Asymmetric C-H bond functionalization reaction is one of the most efficient and straightforward methods for the synthesis of optically active molecules. Herein we disclose an asymmetric C-H/C-H cross-coupling reaction of ferrocenes with azoles such as oxazoles and thiazoles. Palladium(II)/monoprotected amino acid (MPAA) catalytic system which exhibits excellent reactivity and regioselectivity for oxazoles and thiazoles. This method offers a powerful strategy for constructing planar chiral ferrocenes. Mechanistic studies suggest that the C-H bond cleavage of azoles is likely proceeding through a SE Ar process and may not be a turnover limiting step.