Direct Condensation of Sulfonamide and Formamide: NaI-Catalyzed Synthesis ofN-Sulfonyl Formamidine Using TBHP as Oxidant

A new N-sulfonyl formamidine synthesis was developed via NaI-catalyzed direct condensation of sulfonamide and formamide. The green methodology is featured by high atom economy, easily available starting materials, the lack of need for a transition-metal catalyst, no requirement of hazardous reagent, operational simplicity, and good tolerance with diverse functional groups. Mechanistic studies suggest that the protocol proceeds based upon in situ generated TsN·NaI.