Copper-Catalyzed Chemoselective Cyclization Reaction of 2-Isocyanoacetophenone: Synthesis of 4-Hydroxyquinoline Compounds.

A copper-catalyzed intramolecular cyclization reaction of 2-isocyanoacetophenone derivatives to afford 4-hydroxyquinolines chemoselectively is described. The transformation proceeds through enol tautomerism and a subsequent C-C bond formation. Compared to previous methods, this study provides a new protocol for the construction of 4-hydroxyquinoline compounds from functionalized isocyanides under mild conditions.