Regioselective Si-C bond activation in silicon-bridged ansa-cycloheptatrienyl-cyclopentadienyl complexes

On treatment with [Pt(PEt3)3], silicon-bridged ansa-cycloheptatrienyl-cyclopentadienyl Ti and V complexes, [1]silatroticenophane and [1]silatrovacenophane, undergo oxidative addition and regioselective insertion of a Pt(PEt3)2 moiety into the silicon-carbon bond to the seven-membered ring; the resulting complexes, [2]platinasilatroticenophane and [2]platinasilatrovacenophane, can be partly used as single-source catalysts for the ring-opening polymerization (ROP) of the original highly strained sandwich molecules.