Intramolecular homolytic aromatic silylation of biphenyl-2-hydrosilanes via silyl radicals has been developed for the synthesis of silafluorenes. Moreover, silaindenes are synthesized via a silyl radical cascade process, assembling internal alkynes with readily available arylhydrosilanes by C–H and Si–H cleavage and C–C and C–Si bond formation in one step. These represent a new simple and efficient approach towards the synthesis of benzosilole derivatives.