A survey of conditions for the palladium catalyzed intramolecular Heck cyclization of protected amines has shown that the Herrmann–Beller palladacycle can be exploited under 'cationic'conditions to provide a robust and rapid route (< 2h) to the synthesis of single double bond isomer phenanthridines in excellent yield (76–99%). In addition, the same cyclization can be performed under 'neutral'conditions to provide phenanthridines with a ...
