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

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 O-2. 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.