One-pot synthesis of indene derivatives by CF3SO3H-promoted reactions of benzylic alcohols and 1,3-dicarbonyl compounds

An efficient and convenient one-pot synthesis of indene derivatives was achieved in moderate to high yields by the CF3SO3H promoted coupling/cyclization reaction of benzylic alcohols and 1,3-dicarbonyls for the first time. For the reactions of methoxy- or methyl-substituted diarylmethanols with 1,3-dicarbonyls, 2 equiv of CF3SO3H was needed to reach the best results; but for the reactions of methoxy-substituted arylethanols with 1,3-dicarbonyls, 0.6 equiv of CF3SO3H at lower temperatures was capable of promoting the reaction finished.