Synthesis of Alternating Silylether-Carbosilane Copolymers via Tandem Hydrosilylation–Condensation/Ring-Opening and Addition Polymerization

Developing organosilicon materials with special structures is challenging because of the limited number of synthons and monomers. Herein, we afford a tandem hydrosilylation polymerization method to prepare alternating silylether-carbosilane copolymers. Using dihydrosilane and 4-methoxystyrene (or its derivatives) as substrates with B(C 6 F 5 ) 3 as the catalyst, the condensation reaction of hydrosilane with the methoxy group of styrene derivatives, followed by the addition reaction between hydrosilane and the vinyl group, generates the targeted copolymer composed of alternating Si–O–C bonds and Si–C–C bonds. When cyclic benzofuran derivatives are used, the tandem hydrosilylation ring-opening reaction and addition reaction are established. Moreover, the presence of silylether groups endows these copolymers with degradability in acid/base environments. Combined experimental and DFT studies reveal rapid hydrosilylation–condensation, with hydrosilylation addition being the rate-limiting step, while vinyl self-addition is controlled by the input amount of hydrosilane. This method expands the synthetic boundaries of organosilicon materials.