Ruthenium-Catalyzed Sequential Hydrosilylation/Dehydrogenation and C-H Silylation: Synthesis of Six-Membered Indole Silacycles and Pyrrole Silyl Ether Cycles.

Selective dehydrogenative C-H silylation is one of the most powerful tools to synthesize silacycles. Herein, we developed Ru-catalyzed sequential hydrosilylation/C-H silylation of allyl-indoles and dehydrogenative O-H/C-H silylation of pyrrole phenols. Both six-membered indole silacycles and pyrrole silyl ether cycles were successfully synthesized with good functional group tolerance. Furthermore, the RuHCl(CO)(PPh 3 ) 3 catalyst exhibited high reaction compatibility in hydrosilylation of alkene, dehydrogenative O-H silylation, and C-H silylation.