Porous organic polymer immobilized copper nanoparticles as heterogeneous catalyst for efficient benzylic C–H bond oxidation

A facile and practical heterogeneous copper nanoparticles catalyst (Cu@AEPOP) was prepared by the incorporation of Cu(OAc)2 to amide and ether functionalized porous organic polymers (AEPOP) that were efficiently prepared by condensation of 4,4′-diaminodiphenyl ether with 1,3,5-benzenetricarbonyl chloride. The prepared AEPOP and Cu@AEPOP were characterized by SEM, BET, TEM, ICP, FT-IR and XRD. With TBHP (70 wt% in water) as oxidant and solvent, Cu@AEPOP showed excellent catalytic activity for the selective oxidation of benzylic C–H bonds. Among the oxidation of alkyl benzenes to ketones, secondary alcohols to ketones, and primary alcohols to acids, the copper catalyst exhibited remarkable selectivity and reactivity for a broad range of substrates in excellent yields. Furthermore, the experimental operation was very facile and the heterogeneous catalyst could be easily recovered by filtration separation.