Beyond the solvent role: discovery of DMSO as a versatile radical reagent for organic transformations.

DMSO is well-known as a solvent but here we have explored DMSO as a sole reagent for dehydrogenation of tetrahydrocarbazoles, oxidation of alcohols to carbonyl compounds, decarboxylation of keto-acids to aldehydes, and C-C/C-N bond formations via cyclization, self-coupling, the Povarov reaction and Friedlander synthesis via a radical pathway. This methodology involves simple, metal-free and catalyst-free conditions.