Stoichiometric Hydrosilylation of Nitriles with Hydrido(hydrosilylene)tungsten Complexes: Formation of W−Si−N Three-Membered Ring Complexes and Their Unique Thermal Behaviors

Reactions of hydrido(hydrosilylene)tungsten complexes, Cp‘(CO)2(H)WSi(H)[C(SiMe3)3], with nitriles (MeCN, tBuCN) at 60 °C gave hydrosilylation products, Cp‘(CO)2W[κ2(N,Si)-Si(H)(NCHR‘){C(SiMe3)3}] (R‘ = Me, tBu), with a novel W−Si−N three-membered ring structure. The product of the hydrosilylation of tBuCN underwent reversible rearrangement at 70 °C to a silylene complex, Cp‘(CO)2(H)WSi(NCHtBu)[C(SiMe3)3], which was a major component in equilibrium. A reaction mechanism for the hydrosilylation involving coordination of nitriles to the silylene ligand and subsequent migration of the hydrido ligand to the nitrile carbon was proposed.