Magnetite: a Green, Sustainable and Recyclable Catalyst for Direct Synthesis of Thioesters by C−H Activation

Abstract

A green and sustainable approach to the direct synthesis ofthioesters has been developed using Fe3O4 as a low-cost, easilyprepared, reusable and environmentally safe catalyst. The crossdehydrogenative coupling (CDC) of various thiols and aldehydesin water, or even in the absence of solvent, using tertbutylhydroperoxideas oxidant, under ligand and base-free mildconditions, afforded the corresponding thioesters in good toexcellent yields. This simple protocol features broad substratescope, good compatibility with different functional groups, aswell as high atom-efficiency. The scalability, ease of (magnetic)recovery and reuse of the magnetite catalyst are additional ecofriendlyattributes of this methodology. Moreover, the broadsynthetic applications of thioesters further highlight thepotential utility of the present protocol.