Synthesis of di- and trisilanes with potentially chelating substituents

Silylenes 2 or 4, generated by thermolysis of cyclotrisilanes 1 and 3, were inserted into the Si-Cl or Si-H bonds of monosilanes to yield a variety of disilanes. which can be further functionalized subsequently. In a few cases, trisilanes are accessible by the reaction of I with disilanes. The reaction of a metalated silane with a chlorosilane is an alternative method for the formation of Si-Si bonds, which turned out to be especially useful for the synthesis of bulkily substituted disilanes. Some of the new dichlorodiand trisilanes themselves serve as thermal precursors of silylenes 2 or 4, the extrusion of which can be catalyzed by 1 or 3 in certain cases. (C) 2002 Elsevier Science B.V. All rights reserved.