Photo-mediated radical relay oximinosulfonamidation of alkenes with N-nitrosamines triggered by DABSO†

Abstract

N-Nitrosamines represent a class of bifunctional nitrogen-radical precursors, but their application potential remains largely unexplored. This study reports the highly atom-economical production of diverse α-oximino sulfonamides via direct photo-mediated radical relay oximinosulfonamidation of activated or unactivated alkenes with N-nitrosamines triggered by organic sulfide. N-Nitrosamines worked as bifunctional reagents in this transformation, simultaneously generating aminyl radicals and NO radicals. The organic sulfide was designed to act as a radical decaging agent as well as a source of sulfonyl. Its strong radical capturing ability and affinity for alkenes enable the rapid capturing of the aminyl radicals, thereby inhibiting the rapid recombination of radical pairs in the solvent cage. The synthesized oxime units could also be easily converted into other functional groups, leading to selective downstream transformations. The mild photodegradation reaction of harmful N-nitrosoamines showed high functional group tolerance and compatibility, facilitating the late-stage functionalization of natural products and drug molecules, expanding the biologically relevant chemical space.