Intramolecular hydrosilylation as a route to 1-aza-2,4-disilacyclobutanes

[GRAPHICS] The addition of Pt catalyst to trisilyl-substituted amines results in the f ormation of intramolecular cyclization products, Unexpectedly, four-membere d ring products are formed predominantly, rather than the thermodynamically more stable five-membered rings resulting from endo cyclization. The produ cts are quite thermally stable and resist reaction with n-BuLi and n-BuLi/T MEDA, The trisilyl-substituted amine starting materials are prepared from l ithium bis(silyl)amides and chlorosilanes in high yields.