A new method for [c,d]pyridine peri-annelation: synthesis of azapyrenes from phenalenes and their dihydro derivatives

An effective synthesis of various azapyrenes from phenalenes and their dihydro derivatives has been developed using 1,3,5-triazines in polyphosphoric acid (PPA).     

Preparation of phenalenes and hydronaphthacenes through tandem alkyne Fischer-carbene complex coupling and inter- or intramolecular Diels-Alder reactions

The rapid construction of phenalenes through the reaction of 8-alkynyltetralones with Fischer-carbene complexes followed by either an inter- or intra-molecular Diels-Alder reaction is presented. As a showcase of the synthetic utility of this process, the rapid construction of polycyclic ring systems containing the tetracycline core has been demonstrated through an iterative application of this reaction sequence.