Iminonaphthofuranone synthesis via multiple-component cyclization of 2-naphthols using only molecular oxygen†

A multiple-component oxidative cyclization of easily available 2-naphthols, anilines, and ethyl glyoxylate is successfully achieved using only molecular oxygen. The reaction enables green, efficient and highly selective synthesis of iminonaphthofuranones, a category of disperse dyes that are previously inaccessible. The products exhibit a wide spectrum of colors, adjustable from pale orange to dark purple. They are also readily transformed into naphthofuranones and highly functionalized naphthols.