-Proline N-oxide dihydrazides as an efficient ligand for cross-coupling reactions of aryl iodides and bromides with amines and phenols

Abstract

A novel catalytic system based on l -proline N-oxide/CuI was developed and applied to the cross-coupling reactions of various N- and O- nucleophilic reagents with aryl iodides and bromides. This strategy featured in the employment of an l -proline derived dihydrazides N-oxide compound as the superior supporting ligand. By using this protocol, a variety of products, including N-arylimidazoles, N-arylpyrazoles, N-arylpyrroles, N-arylamines, and aryl ethers, were synthesized with up to 99% yield. • A novel l -proline based N-oxide ligand has been designed and synthesized. • The developed ligand performed well in copper catalyzed Ullmann-type cross-coupling reactions. • This ligand showed high compatibility in both C–N and C–O bond formation reactions. • A broad substrate scope with respect to both coupling components worked efficiently in high yields.