Synthesis, Characterization, and Antioxidant Evaluations of New 2‐Oxochromene and Benzofuran Derivatives Catalyzed by KF/CP

An eco‐friendly one‐pot procedure has been developed for the preparation of novel 2‐oxochromene and benzofuran derivatives through the sequential addition/intramolecular cyclization reactions of 1‐(6‐hydroxy‐2‐isopropenyl‐1‐benzofuran‐5‐yl)‐1‐ethanone, activated acetylenic compounds, and triphenylphosphine in the presence of catalytic amount of potassium fluoride impregnated clinoptilolite nanocatalyst in water at room temperature. The antioxidant activities of the newly synthesized derivatives (4a, 4b, and 5a) were also screened by diphenyl‐2‐picrylhydrazyl radical scavenging and ferric ion reducing potential assays compared with the synthetic antioxidants (2‐tert‐butylhydroquinone and butylated hydroxytoluene). Compounds 4a and 4b were shown good antioxidant activities.