Palladium/NBE-Catalyzed Regioselective C-H Silylation: Access to Divergent Silicon-Containing Indoles.

A palladium/norbornene (NBE)-catalyzed regioselective C-H silylation of free NH-indoles is reported. This protocol uses Pd(OAc) 2 as the catalyst and Cu(OAc) 2 as the oxidant, and the reaction relies on the control of NBE as a switch. The reaction tolerates various functional groups, and a series of silicon-containing indoles were directly synthesized in 30%-94% yields.