Catalyst-controlled regio- and chemodivergent C–H functionalization of imidazopyridines with TIPS-protected terminal alkynes

Abstract

Catalyst-controlled regio- and chemodivergent C–H functionalization provides a powerful approach for the rapid diversification of heteroaromatic scaffolds. Herein, we report a palladium(II)- and rhodium(I)-catalyzed regio- and chemodivergent C–H functionalization of imidazo[1,2-a]pyridines with terminal alkynes. Selective access to C3-alkynylated products via Pd(II)-catalyzed oxidative C–H alkynylation or to ortho-alkenylated products through Rh(I)-catalyzed chelation-assisted C–H activation is achieved simply by switching the catalyst. This protocol exhibits broad substrate scope, high regioselectivity, and efficient utilization of terminal alkynes as versatile coupling partners.