Uncatalyzed, green aza-Michael addition of amines to dimethyl maleate

Dimethyl maleate was found to be a very reactive and selective acceptor for the aza-Michael addition in comparison to other commonly used electron-deficient alkenes. It reacts efficiently with a variety of aliphatic amines in complete absence of any catalyst and solvent at room temperature. Under these environmentally-friendly conditions, high yields of selectively mono-adducts were obtained within short reaction times.