Synthesis of the Naphthalenone,Dihydroquinoline, and Dihydrofuran Derivatives

The reactions of enaminones with dimethyl diazomalonate were investigated in the presence of copper(II) acetylacetonate. From the reaction of (E)‐3‐[methyl(phenyl)amino]‐1‐phenylprop‐2‐en‐1‐one ( 6c ), dimethyl 2‐[methyl(phenyl)amino]‐4‐oxonaphthalene‐1,1‐(4H)‐dicarboxylate, was unexpectedly obtained as the major product. Quinoline derivatives were formed as the major products in the case of N‐methyl‐p‐anisidino and N‐methyl‐p‐toluidino enaminones. The reactions of acetyl enaminones were also realized, and quinoline derivatives were isolated as the major products. 3H‐ and 5H‐dihydrofurans were also formed as side products in these reactions. These results differ from those reported earlier on the reactions of tertiary enaminones with carbenes/metal carbenes.