TBHP-promoted sequential radical silylation and aromatisation of aryl isonitriles with silanes

The tert-butyl hydroperoxide (TBHP) promoted sequential silylation and aromatisation of isonitriles was developed, where the silyl group was regioselectively installed at the 6-position of phenanthridines. This procedure tolerates a series of functional groups, such as fluoro, chloro, acetyl, methoxy carbonyl, cyano and trifluoromethyl. The addition of a silyl radical to the isonitrile followed by an intramolecular aromatic cyclization was involved in this transformation.