One-pot synthesis of poly(alkoxysilane)s by SiSi/SiO dehydrocoupling of silanes with alcohols using Group IV and VIII metallocene complexes

SiSi/SiO dehydrocoupling reactions of silanes with alcohols (1:1.5 mole ratio), catalyzed by Cp2MCl2/Red-Al (M=Ti, Zr) and Cp2M′ (M′=Co, Ni), produced poly(alkoxysilane)s in one-pot in high yield. The silanes included p-XC6H4SiH3 (X=H, CH3, OCH3, F), PhCH2SiH3, and (PhSiH2)2. The alcohols were MeOH, EtOH, iPrOH, PhOH, and CF3(CF2)2CH2OH. The weight average molecular weight of the poly(alkoxysilane)s ranged from 600 to 8000. The dehydrocoupling reactions of phenylsilane with ethanol (1:1.5 mole ratio) using Cp2HfCl2/Red-Al and phenylsilane with ethanol (1:3 mole ratio) using Cp2TiCl2/Red-Al gave only triethoxyphenylsilane as product.