Divergent oriented synthesis (DOS) of aza-heterocyclic amides through palladium-catalyzed ketenimination of 2-iodo-N-(propa-1,2-dien-1-yl)anilines

Abstract

A palladium-catalyzed tandem reaction of N-(2-iodophenyl)-4-methyl-N-(propa-1,2-dien-1-yl)benzenesulfonamide with isocyanide is described to divergently produce aza-heterocyclic amides. The success of this reaction relies on a versatile synthetic intermediate, 2-(1H-indol-3-yl)ethen-1-imine, which was proposed to be generated through oxidative addition of palladium, regioselective addition of an allene group, 1,1-insertion of isocyanides, and β-H elimination.