Silicon Acetal Metathesis Polymerization

A kinetic study revealed that the acid-catalyzed (p-TSA) equilibration of Me₂Si(OMe)₂ and Me₂Si(OEt)₂, forming Me₂Si(OEt)OMe, is established in 300 min in benzene at room temperature. This silicon acetal metathesis reaction is exploited for the step-growth polymerization of bis-silicon acetals (MeOSiMe₂OROSiMe₂OMe) with metathetical loss of Me₂Si(OMe)₂. Thus, a convenient and generalized silicon acetal metathesis polymerization (SAMP) method is introduced as the acid-catalyzed copolymerization of a diol (HOROH) and Me₂Si(OMe)₂, driven by elimination of methanol and/or Me₂Si(OMe)₂. SAMP constitutes an effective and powerful strategy for manipulating the most common bond in the Earth's crust, the silicon-oxygen bond.