Pd-Catalyzed Asymmetric Oxidative C-H/C-H Cross-Coupling Reaction between Ferrocenes and Azoles

J Org Chem. 2023 May 5;88(9):5752-5759. doi: 10.1021/acs.joc.3c00212. Epub 2023 Apr 21.

Abstract

The asymmetric C-H bond functionalization reaction is one of the most efficient and straightforward methods for the synthesis of optically active molecules. Herein, our work discovered a Pd-catalyzed asymmetric oxidative C-H/C-H cross-coupling reaction of ferrocenes with azoles such as oxazoles and thiazoles. Mono-N-protected amino acid as chiral ligands with palladium(II) has been demonstrated as an effective catalytic system in a weakly azine-directed asymmetric C-H bond functionalization reaction. This method offers a powerful strategy for constructing various substituted planar chiral ferrocenes via a dual C-H bond activation pathway in medium yields (up to 70%) with good enantioselectivity (up to 95.3:4.7 er) under mild conditions.