Arylphosphonylation and Arylazidation of Activated Alkenes

Two radical‐mediated processes of activated alkenes, namely arylphosphonylation and arylazidation, are described. The difunctionalization of alkenes by a tandem process that involves radical addition, 1,4‐aryl migration, and desulfonylation generates α‐aryl‐β‐heterofunctionalized amides bearing a quaternary stereocenter when the substituent on the nitrogen atom is an aryl group. Alternatively, heterooxindoles or spirobicycles can be obtained with excellent regioselectivity in the presence of an alkyl substituent on the nitrogen atom. Radical difunctionalization: The addition of heteroatom‐centered radicals to the double bond of arylsulfonyl acrylamides furnishes alkyl radical intermediates. A reaction cascade is then triggered so that α‐aryl‐β‐heterofunctionalized amides with a quaternary stereocenter are obtained by the simultaneous formation of CC and CP/CN bonds across the double bond. Heterofunctionalized oxindoles can also be synthesized.