Functionalization of vinyl-substituted cyclosiloxane and cyclosilazane via ruthenium-catalyzed silylative coupling reaction

摘要

A new type of functionalization of cyclosiloxane and cyclosilazane is reported. Commercially available vinyl-substituted cyclosiloxane and cyclosilazane can be converted chemo- and regioselectively to styryl- and beta-alkoxyvinyl-substituted derivatives via respective silylative coupling reactions with styrene and vinyl alkyl ethers catalyzed by RuHCl(CO)(PCy3)(2). The obtained cis-tristyrylcyclotrisiloxane showed a unique arrangement of the three styryl groups through face-to-face and side-by-side pi-pi interactions. Pd-catalyzed Hiyama coupling reaction of synthesized beta-n-butoxyvinyl-substituted cyclosiloxane with iodobenzene was also performed to afford beta-n-butoxystyrene regioselectively. [References: 46]