A Catalyst and Base Free Approach to Polycyclic Aromatic Compounds via Intramolecular [2+2] and retro-[2+2] Cycloadditions

An efficient one-pot strategy for the preparation of polycyclic aromatic compounds (PACs) has been developed. The catalyst and base free conditions, short reaction time under microwave irradiation, as well as the moderate to high yields of products, make the methodology more convenient and feasible. The mechanism study reveals that a novel cascade of thermal induced intramolecular [2+2] cycloaddition of bis-N-tosylhydrazones and retro-[2+2] cycloaddition of 1,2-diazetidines was involved in the reaction between biaryl dicarbonyl compounds and p-tolylsulfonylhydrazine.

Automated summary

An efficient one-pot strategy for the preparation of polycyclic aromatic compounds (PACs) has been developed, utilizing catalyst and base free conditions, short reaction time under microwave irradiation, and moderate to high yields of products. Mechanism study reveals a novel cascade of thermal induced intramolecular [2+2] cycloaddition and retro-[2+2] cycloaddition involved in the reaction process.