Phenylethenyl-substituted silicones via Heck coupling reaction

Systematic studies of several palladium complexes (Pd(OAc)2, [PdCl2(cod)], [Pd2(dba)3], [Pd(PPh3)4], [PdCl(SnCl3)(P{p-Tol}3)2], [Pd2Cl2(SnCl3)2(P{p-Tol}3)2]) as potential catalytic systems for arylation of vinylsiloxanes via Heck coupling reactions are described. Catalytic activity and selectivity were studied for a model reaction of trimethylvinylsilane with PhBr and m-ClC6H6Br and then the most effective systems were applied for functionalisation of tetramethyltetravinylcyclotetrasiloxane and poly(dimethylsiloxane-co-methylvinylsiloxane), leading to the silicone fluids having high refractive index (1.5–1.6).