A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C H bond, cleavage of inert C C bond, and formation of C O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
The nickel phosphides have garnered increasing attention as an excellent catalytic site in the fields of electrocatalysis and hydrotreating, but their application in organic synthesis remains infrequent. In this study, ammonium phosphate and nickel chloride were employed as the doping sources for the first time to synthesize the Ni-based ZIF-8 precursor via the host–guest method. Subsequently, the precursor was pyrolyzed to obtain Ni2P nanoparticles (NPs) supported on N, P co-doped carbon. The composite materials exhibit elevated metal loading and effective dispersion due to the synergistic combination of phosphorus and nickel. Specifically, compared with Ni-NC, the optimal Ni2P-NCP-1 exhibits enhanced catalytic activity in the α-alkylation of arylacetonitriles with alcohols using KOH as the base. It shows a wide broad substrate scope at 140 °C for 12 h in n-octane using a hydrogen borrowing strategy. Through characterizations and mechanistic studies, it has been discovered that the introduction of P source not only provides more basic sites on carbon matrix but also leads to the formation of Ni2P NPs, which facilitates the catalytic efficiency by modifying the electronic structure of Ni. Compared with the metallic Ni species, the synergistic effect between Ni2P and acid-basic sites significantly influences the dehydrogenation of alcohols to generate Ni–H species. This study successfully achieves simultaneous phosphating of both the metal and support, and it also demonstrates that the N2P-NCP-1 catalyst has significant potential in the heterogeneous organic transformation field.
Graphical Circular Economy : A sustainable methylation process is developed using only inexpensive methanol and bio-based chemicals with a very easy workup and purification procedure. Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O -methylated phenols and benzoic acids, and mono- C -methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Brønsted base.