Ene-1, 1-diamines (ketene aminals, A) are a special class of olefins distinguished by a very electron rich and strongly polarized double bond.[1] This dipolar character is caused by the significant contribution from the mesomeric extreme A'to their ground-state structure (Scheme1), and becomes particularly prominent if the nitrogen atoms are part of a heterocyclic ring able to accommodate positive charge. Likewise, coordination to a ...
