The decarboxylative and dehydrogenative coupling of formate: from anisyl formate to a high value-added diamine

The deoxygenative carbon-carbon bond formation from alcohols remains a formidable challenge toward cleaner coupling reactions. In this work, we first unlocked a novel homocoupling upgrading mode of benzyl alcohol by virtue of the two-side roles of the pre-introduced formyl group, which serves as both impetus for easier C-O bond dissociation and an endogenous hydrogen source. As a proof-of-concept, the decarboxylative and dehydrogenative homocoupling of anisyl formate toward 1,2-bis(4-methoxyphenyl)ethane was realized using a Ru/MoS₂ catalyst with an optimized yield of 66%. Structural characterizations and control experiments indicated the synergy effect between Ru and Mo. A tailored nitration-reduction route was further designed for upgrading the coupling product into a high value-added aromatic diamine, the overall yield of which reached 56% based on anisyl formate. This method opens a new avenue for catalytic transformations of alcohols through ester intermediates.