Silica-supported poly-gamma-aminopropylsiloxane palladium(Pd~(2+))-transition metal(Cu~(2+))complex:A new catalyst system for Heck reaction

摘要

A new silica-supported poly-gamma-aminopropysiloxane transition metal(Cu~(2+))and palladium(Pd~(2+))catalyst has been prepared from organic silica via immobilization on fumed silica,followed by treatment with Cu(OAc)_2 and PdCl_2 in ethanol.The catalyst is efficient for Heck arylation of aryl iodides with alkene.The effects of reaction temperature and Pd~(2+)content on catalytic properties have also been studied.Pd~(2+)has been found to improve the catalytic performance,reducing the reaction temperature(70 deg C)and the induction period.It provides an economic way to synthesize unsymmetrical trans-stilbenes.