Aerobic {Mo72V30} nanocluster-catalysed heterogeneous one-pot tandem synthesis of benzimidazoles

摘要

A novel heterogeneous one-pot protocol is developed for tandem aerobic synthesis of benzimidazoles through dehydrogenative coupling of primary benzylic alcohols and aromatic diamines co-catalysed by Keplerate-type {Mo72V30} polyoxometalate and N-hydroxyphthalimide (NHPI). The catalytic system also works well for the synthesis of benzimidazoles using benzaldehydes, as commonly used starting materials, in the absence of NHPI. The high activity of the solid nanocluster provides standard conditions avoiding current limitations of oxidation methods including high catalyst loadings. The spectral results and leaching experiments revealed that the nanocapsule preserved its structural integrity after being reused in consecutive runs.