New In(OiPr)3-MCM-41 heterogeneous catalyst in MPV reductions of unsaturated carbonyl compounds: effect of mesoporous SBA-15 and MCM-41 as supporting surfaces on catalytic activity of In(OiPr)3

Abstract

Indium tri-isopropoxide, In(OiPr)3, was immobilized on mesoporous material, MCM-41, and denoted as “In(OiPr)3-MCM-41”. This new heterogeneous catalyst was characterized by XRD, 29Si NMR-, N2 adsorption–desorption isotherms and ICP-OES techniques. The new heterogeneous catalyst, In(OiPr)3-MCM-41, was tested for the capable of catalyzed Meerwein–Ponndorf–Verley (MPV) reduction of unsaturated aldehydes and ketones with low catalyst loadings under mild conditions and showed good to excellent catalytic activities. Also, effect of supporting surfaces, both of SBA-15 and MCM-41, on catalytic activity of In(OiPr)3 were examined. In(OiPr)3-SBA-15 heterogeneous catalyst in comparison with the In(OiPr)3-MCM-41 catalyst, display comparatively higher catalytic activity in the MPV reduction of unsaturated aldehydes and ketones. Also, similiar reaction times and selectivities for the unsaturated alcohols were obtained with the In(OiPr)3-SBA-15 catalyst compared with the In(OiPr)3-MCM-41 catalyst. The reason for the lower activity observed for MCM-41 sample may be due to smaller pore size of the In(OiPr)3-MCM-41 catalyst as compared with In(OiPr)3-SBA-15 catalyst can creat restrict site accessibility for the carbonyl compounds. Eventually, effect of supporting surfaces, SBA-15 and MCM-41, on catalytic activity of In(OiPr)3 insignificant for MPV reduction of unsaturated carbonyl compounds. © 2016, Springer Science+Business Media Dordrecht.