A Pincer Ruthenium Complex for Regioselective C–H Silylation of Heteroarenes

A pincer Ru(II) catalyst for the highly efficient undirected silylation of O- and S-heteroarenes with (TMSO)2MeSiH and Et3SiH is described, producing heteroarylsilanes with exclusive C2-regioselectivity, good functional-group tolerance, and high turnover numbers (up to 1960). The synthetic utility of the silylated products is demonstrated by Pd-catalyzed Hiyama–Denmark cross-coupling under mild conditions. One-pot, two-step silylation and coupling procedures have been also developed.