Molecular design of selective oxidation catalyst with polyoxometalate

Efficient H2O2-based oxidation systems with three kinds of polyoxometalates, [(gamma)- SiW10O34(H2O)2]^4- (1), [(gamma)-1,2H2SiV2W10O40]^4- (2), and [W2O3(O2)4(H2O)2]^2- (3) are reported. The compound 1 can catalyze epoxidation of various olefins including non-activated terminal olefins such as propylene and 1-octene with >99% selectivity to epoxide and >99% efficiency of H2O2 utilization. It is notable that 2 shows unique stereospecificity, regioselectivity, and diastereoselectivity for the epoxidation of cis/trans olefins, non-conjugated dienes, and 3-substituted cyclohexenes, respectively. The epoxidation of various allylic alcohols with only 1 equiv. H2O2 in water can be efficiently catalyzed by 3 to give the corresponding epoxy alcohols in high yields. Further, the catalyst 3 can be recycled with the maintenance of the catalytic performance.