Electrochemical oxygenation of diorganyldichlorosilanes: a novel route to generation of diorganylsilanones

Interaction of diorganyldichlorosilanes R2SiCl2 (R = Me, Et, Ph) with super oxide or peroxide anions, produced in situ by electroreduction of molecular oxygen, provides short-living diorganylsilanones R2Si=O. The latter underg o cyclization to give lower perorganylcyclosiloxanes (R2SiO)(n), n = 3 or 4 and then insert to the molecules of these primary products to form higher cyclic oligomers. When the process is carried out in the presence of a reag ent-trap for silanones (hexamethyldisiloxane, hexamethylcyclotrisiloxane), the products of insertion of diorganylsilanones into the molecule-traps (Me 3Si(OSiR2)(n)OSiMe3 with n greater than or equal to 1, and (Me2SiO)(3)(R2Si O)(m), with m greater than or equal to 1, respectively) were obtained. (C) 2000 Elsevier Science B.V. All rights reserved.