437 Silane to Siloxane Transformation: Mechanism and Scope of the Reaction

Friday, November 6, 2009: 11:20 AM
Pancho Villa (Camino Real Hotel)
Keith H. Pannell , Department of Chemistry, University of Texas at El Paso, El Paso, TX
Hemant K. Sharma , Chemistry, U. T. El Paso, El Paso, TX
Siloxanes and polysiloxanes are important materials with very wide application.  They are generally often formed via controlled hydrolysis of halosilane precursors.  However, we have recently discovered that silanes containing a silicon-hydrogen bond can be transformed to disiloxanes via a transition metal-catalyzed reaction not involving water. Thus, for example, R3SiH readily transforms to R3SiOSiR3 via an oxygen transfer reaction  from N,N-dimethylformamide in the present of Fe and Mo catalysts. This reaction can occur both thermally or photochemically depending upon the nature of the ligands attached to the transition metal center. The mechanism and full scope of the reaction will be discussed along with the potential to produce new metal containing polysiloxanes.