PdII‐Catalyzed Regio‐ and Enantioselective Oxidative C−H/C−H Cross‐Coupling Reaction between Ferrocenes and Azoles

An asymmetric C−H/C−H cross‐coupling reaction of ferrocenes with azoles such as oxazoles and thiazoles is presented. Palladium(II)/monoprotected amino acid (MPAA) catalytic system exhibits excellent reactivity and regioselectivity for oxazoles and thiazoles. This method offers a powerful strategy for constructing planar chiral ferrocenes.

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 S_EAr process and may not be a turnover limiting step.

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