2-(2-Tosylhydrazineylidene)acetyl chloride: an unexplored diazo reagent for the synthesis of cyclopropane fused dihydroquinolones

Abstract

Cyclopropane fused dihydroquinolones are prevalent in numerous biologically active compounds and exemplify important scaffolds in medicinal chemistry. We herein describe a wide scope methodology for the direct and modular synthesis of cyclopropane fused dihydroquinolones from a unique α-diazo acylating agent, 2-(2-tosylhydrazineylidene)acetyl chloride. The operationally simple transformation, which proceeds through successive acylation and intramolecular cyclopropanation, allows a broad range of functional groups and yields a wide spectrum of complex molecular scaffolds, including spiro ring systems.