Tandem copper (Cu) catalysed N-arylation–vinylogous nitroaldol condensation of 3,5-disubstituted 4-nitropyrazoles

Abstract

A tandem process involving copper catalysed N-arylation and vinylogous nitroaldol condensation is described. The reaction of 3,5-dialkyl substituted 4-nitropyrazoles and ortho-halo substituted (hetero)aryl aldehydes or ketones furnished 3-nitropyrazolo[1,5-a]quinoline and heteroaryl-fused 3-nitropyrazolo[1,5-a]pyridine derivatives in moderate to high yields.