Additive-Free Nickel-Catalyzed Debenzylation Reactions via Hydrogenative C–O and C–N Bond Cleavage

C-O and C-N cleavage reactions play a fundamental role in synthetic chemistry and biomass valorization. Many efforts have been done in the past in order to develop efficient catalysts able to mediate these transformations. However, still some drawbacks are present: necessity for additives and occurrence of side reactions. Here, an array of Ni-based catalysts derived from the thermal decomposition of a Ni(II)/phenanthroline complex onto different supports was prepared. Ni-N-c@Al2O3-1000 material (pyrolyzed at 1000 degrees C) was the most efficient catalyst for both O- and N-debenzylation of various substrates (>20 examples) using dihydrogen as reductant. Advantageously, this process is water tolerant, proceeds free of any additive, and does not show overhydrogenation of the arene ring. The structure, morphology, and chemical composition of Ni-N-C@Al2O3-1000 have been elucidated. It is constituted by variously sized Al2O3-supported Ni(0)/NiOx nanoparticles (NPs) embedded by layers of nitrogen-doped carbon.