Pd-Catalyzed oxidative annulation of enamides with diazabicyclic olefins: rapid access to cyclopentene fused 2-pyrrolines.

An efficient stereoselective route for the synthesis of cyclopentene fused 2-pyrrolines has been established via a Pd-catalyzed C-H activation/oxidative coupling of aryl enamides with diazabicyclic olefins. The proposed two-stage mechanism was successfully proven by isolating the intermediate trans-disubstituted cyclopentene.