Polyethylene glycol immobilized on silica gel as a new solid–liquid phase-transfer catalyst for regioselective azidolysis of epoxides in water: An efficient route to 1,2-azido alcohols

Polyethylene glycol, a polymer widely used for biomedical applications and in supported synthesis, was easily immobilized on silica gel and used as a new solid–liquid phase-transfer catalyst. It is proved to be an efficient heterogeneous catalyst for regioselective ring opening of epoxide by azide ion in water to give azidohydrine in excellent yield under mild reaction conditions. The polymeric catalyst easily recovered by simple filtration, shows no appreciable loss of activity when recycled several times.