Synthesis of Tetrasubstituted\nEnamines Using Secondary\nAmines and In Situ-Generated Allenes from Nitrocyclopropanes

A novel reaction of cyclic and acyclic secondary amines\nwith in\nsitu-generated allene intermediate species from nitro-substituted\ndonor–acceptor cyclopropanes is reported. In the presence of\na simple inorganic base, NaOH, tetrasubstituted enamine derivatives\ncan be obtained in moderate to excellent yields. The reaction is operationally\neasy, features mild reaction conditions and simple inorganic bases,\nand is free of transition metals.