Merging Cobalt-Catalyzed C-H Activation with the Mannich Reaction: An Efficient and Modular Approach to a-Substituted Sulfonamides

A three-component synthesis of alpha-substituted sulfonamides from aryl aldehydes, primary sulfonamides and (hetero)arenes is described. This transformation enables a straightforward and modular synthesis of pharmaceutically relevant scaffolds in good yields. The direct functionalization of C(sp2)-H bonds via cobalt-catalyzed C-H-activation offers an appealing and atom-economical alternative to classical methods for the synthesis of alpha-arylated amines such as the Petasis or Mannich-type reactions.