Functionalized imidazolium salt: an efficient catalyst for Buchwald–Hartwig type C–N cross-coupling of (hetero)aryl chlorides/bromides with amines under solvent-, inert gas-, and base-free ambience

Abstract

The intermingling of novel imidazolium salt (HL₁-Br) and Cu(OAc)₂ has been marked down as a highly efficient catalytic system for Buchwald–Hartwig-type C–N coupling of a variety of amines with (hetero) aryl bromides/chlorides. In contrast to the whole realm of C−N coupling, the developed protocol is facilitated under base-, solvent-, and inert-gas-free conditions. The established NHC-based imidazolium salt 3-(2-(2-methoxyphenyl)-2-oxoethyl)-1-(pyridin-2-yl)-1H-imidazo-3-ium bromide (HL₁-Br) along with Cu cooperate to undergo various types of diversification. This broadens the range of C–N coupling in numerous applications and gives rise to innovative solutions for challenges in catalytic, synthetic chemistry and drug discovery. The developed reaction proceeds at 110 °C and produces a broad spectrum of substrates in good to excellent yields.