Coupling of N-Nosylhydrazones with Nitrosoarenes: Transition-Metal-Free Approach to (Z)-N-Arylnitrones

Abstract

An efficient and transition-metal-free protocol for the synthesis of (Z)-N-arylnitrones from the direct coupling of N-nosylhydrazones with nitrosoarenes under mild conditions is described. The protocol is compatible with a wide range of functional groups placed on both the reagents and provided the corresponding nitrones in good to excellent yields by simple recrystallization process. The use of these 1,3-dipoles for the synthesis of substituted indoles is elaborated for 2,3-diphenyl-1H-indole.