Synthesis of Secondary Amides from Thiocarbamates.

The synthesis of secondary amides from readily accessible and bench-stable substituted S-phenyl thiocarbamates and Grignard reactants is reported. Oxidative workup allows recycling of the thiolate leaving group as diphenyl disulfide. Diphenyl disulfide can be transformed into S-phenyl benzenethiosulfonate, a reactant required for thiocarbamate synthesis. This amide synthesis is suitable for the preparation of challenging amides that are not or hardly accessible via classical approaches.