A Novel Synthesis of Isoflavones via Copper(I)-Catalyzed Intramolecular Cyclization Reaction.

Isoflavone derivatives were synthesized via intramolecular cyclization of 3-(2-bromophenyl)-3-oxopropanal derivatives, using CuI as the catalyst, 2-picolinic acid (=pyridine-2-carboxylic acid) as the ligand, K2CO3 as the base, and DMF as the solvent, in up to 96% yield. The synthesis is functional group-tolerant.