PEG-Mediated Catalyst-Free Expeditious Synthesis of Functionalized Benzene/Biaryl and Fluoren-9-one Derivatives from Activated Acetylenes and 1,3-Diones
A benzannulation reaction of β-diketones with dimethylacetylenedicarboxylate catalyzed by pyridine and potassium tert-butoxide is described. Fully substituted benzenes are synthesized from simple and commercially available starting materials under mild conditions in high yields. benzannulation - dimethylacetylenedicarboxylate - pyridine - β-diketones - potassium tert-butoxide