Cu-Catalyzed carbamoylation versus amination of quinoline N-oxide with formamides

Abstract

An efficient, direct carbamoylation and amination of quinoline N-oxides with formamides to access 2-carbamoyl and 2-amino quinolines has been developed through copper-catalyzed C–C and C–N bond formations via cross-dehydrogenative coupling reactions. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance under mild conditions. Mechanistic studies suggest that the reaction is initiated by formamide radical or decarbonylative aminyl radical formation in the presence of TBHP, according to the different substituent on the N atom of formamide.