Base-Promoted/Gold-Catalyzed Intramolecular Highly Selective and Controllable Detosylative Cyclization.

A highly selective, controllable and synthetically useful base-promoted intramolecular detosylative cyclization of bis-N-tosylhydrazones has been achieved, affording N-containing heterocycles and cyclic olefins under transition-metal-free or gold-catalyzed procedures, respectively. Moreover, an effective and practical metal-free or gold-catalyzed approach to synthesize polycyclic aromatic compounds is also reported.