Novel inorganic oxide supported organotin hydrides for fine chemical catalysis

Abstract

Chemically tethered organotin hydride on various acid pre-treated metal oxide surfaces has been prepared through reaction of surface hydroxyl groups with the hydrostannated product of trimethoxyvinylsilane with dibutyltin dihydride. It was found that some support oxides, typically hydroxylated silicas, clearly show hydride carrying capacities comparable to the best polymer supported hydrides reported but with expected advantages in mechanical and thermal stability. It is also shown, for the first time, that these oxide-supported hydrides can be used as cleaner and genuine heterogeneous catalysts. In the presence of sodium borohydride, the depleted hydrides can be regenerated in situ and complete the catalytic cycle. Therefore, novel heterogeneous catalytic hydrogenation reactions and intramolecular coupling reactions using the supported organotin hydride catalyst are demonstrated.