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 bissilicon 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.