Ring-closing enyne metathesis of allylic and propargylic cyanamides

A straightforward entry to 5-membered cyclic cyanamides from readily available allylic and propargylic cyanamides is reported. These starting materials are easily obtained by a multicomponent A 3 coupling followed by a von Braun reaction and they were shown to be readily cyclized by a ring-closing enyne metathesis, upon simple reaction with Grubbs II catalyst, to the corresponding highly functionalized cyclic cyanamides.