Titanium silicate molecular sieves (TS-1 and TS-2) catalyzed Michael reaction of silyl enol ethers with ?,? unsaturated carbonyl compounds

Abstract

The Michael addition reaction has been carried out with silyl enol ether and Michael acceptors such as acrylates, and α, β- unsaturated ketones over aluminum-free titanium silicates (TS-1 and TS-2) in the absence of H2O2. The reaction was carried out slightly above room temperature (40°C) in the presence of dry solvents giving moderate to good yield. The effect of various modified zeolites like RE-Y, La-Y, steamed-Y, Na-Y, VS-1, SnS-1, Zn/ZSM-5 and different solvents has been studied. The catalytic activity is explained on the basis of “oxophilic Lewis acidity” of titanium silicate molecular sieves.