Dioxirane-mediated heterogeneous epoxidations with potassium caroate: A solid catalyst bearing anchored ketone moieties

A new hybrid material (3) consisting of trifluoromethyl ketone (TFMK) moieties, immobilized on silica through an appropriate spacer, was synthesized and characterized. Lacking easily oxidizable functionalities in the spacer chain, this material proved to be an excellent catalyst in heterogeneous epoxidations with potassium caroate (KHSO 5), surpassing other reported catalysts in performance and stability. The efficiency of silica-supported catalyst 3 could be assessed upon carrying out the selective dioxirane-mediated epoxidation of representative alkenes in high yields. The solid catalyst could then be recovered and reused in a number of consecutive oxidation cycles. The synthesis of a new hybrid, which presents trifluoromethyl ketone moieties anchored on silica gel through a short spacer, is reported. Lacking easily oxidizable functionalities in the linker chain, this solid material is an efficient catalyst in dioxirane-mediated heterogeneous epoxidations using potassium caroate.