Radical cross-coupling preserves stereochemistry, enabling new chiral building blocks
Baran and coworkers report a nickel-catalyzed alkyl-alkyl cross-coupling that forms a C–C bond between a chiral sulfonylhydrazide radical and an alkyl halide without racemizing the stereocenter, achieved via a diazene-cage mechanism. This unusual radical process preserves enantioenrichment in the product, enabling direct access to chiral motifs like piperidines and pyrrolidines without chiral ligands or directing groups, though the method currently works best with cyclic sulfonylhydrazides and requires further scope expansion.
