Hydrosilylation reaction based on vinyl silyl substituted polymers

Platinum compounds are extremely active catalysts for hydrosilation reaction. The catalyst is often used at such low levels that it is not separated from the product. Originally, chloroplatinic acid was used as a hydrosilation catalyst (Speier’s catalyst). However this compound is a potent sensitiser and is hazardous to health [1]. Herein, A new polymeric support based on multifunctional, exceptionally sterically hindered carbosilane moieties (tris(dimethylvinyl)nethyl), grafted onto linear poly(styrene-co-chloromethylstyrene), was prepared. Platinum was bound to –CH=CH2 groups of trisilated supports in reaction with H2PtCl6×6H2O, using the literature procedure [2]. The molar ratio [–CH=CH2]/[H2PtCl6] = 3 was used, according to the known stoichiometry of [Pt]/[–CH=CH2] in Pt-2,4- divinyl-tetramethyldisiloxane complex (Karstedt’s catalyst) [3]. It was found that there is a certain limiting amount of Pt, that can be introduced into poly(styrene)-co-[1,1-tris(dimethylvinyl)ethylstyrene]. Such the catalytic system makes an interesting alternative for heterogeneous platinum catalysts Speier’s catalyst and also to Karstedt’s catalyst, when used in hydrosilylation of vinylsilanes.