Cu-MOFs as active, selective and reusable catalysts for oxidative C O bond coupling reactions by direct C H activation of formamides, aldehydes and ethers

Abstract

MOFs with Cu2+ centers linked to four nitrogen atoms from azaheterocyclic compounds, i.e., pyrimidine [Cu(2-pymo)2] and imidazole [Cu(im)2], are active, stable and reusable catalysts for oxidative C O coupling reactions by direct C H activation of formamides, aldehydes and ethers. The measured catalytic activities are clearly superior to other homogeneous cupric salts, especially for the [Cu(im)2] MOF. The previously reported activity of the Cu2+ centers for cumene oxidation allows the use of the MOF as a bifunctional catalyst for olefin epoxidation with O2. The overall catalytic process consists of a cascade reaction in which the Cu-MOF first produces cumyl hydroperoxide and then the same Cu2+ centers catalyze the oxidative C O coupling reaction using the generated hydroperoxide as the oxidant.