Electrochemical activation of diorganyl dialkoxysilanes for siloxane backbone extension

The reaction of diorganyl dialkoxysilanes PhRSi(OAlk)2 (R = Ph, vinyl, OMe; Alk = Me, Et) with electrochemically reduced forms of oxygen provides reactive intermediates that insert into hexamethyldisiloxane or permethyl cyclosiloxanes, D3 and D4, to give siloxane products with one additional PhRSiO fragment; the process is thought to occur with the intermediacy of diorganylsilanones.