Synthesis of Chromones via Palladium-Catalyzed Ligand-Free Cyclocarbonylation of o-Iodophenols with Terminal Acetylenes in Phosphonium Salt Ionic Liquids
Qian Yang and Howard Alper*
*Centre for Catalysis Research and Innovation, Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5, Canada, Email: howard.alperuottawa.ca
Q. Yang, H. Alper, J. Org. Chem., 2010, 75, 948-950.
A highly efficient and selective palladium-catalyzed ligand-free cyclocarbonylation reaction of o-iodophenols with terminal acetylenes under atmospheric CO pressure affords diversified chromones in very good yields. The use of a phosphonium salt ionic liquid as the reaction medium enhances the efficiency of the cyclocarbonylation reaction.
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