Catalyst-controlled regio- and chemodivergent C-H functionalization of imidazopyridines with TIPS-protected terminal
Tiantian Zhu1, Qiang Zhang1, Xianling Li1
1Guangxi Laboratory of Low-carbon Technology and Green Chemical Advanced Materials, School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, China. szhao@gxu.edu.cn.
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.
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