Janka M, He W, Frontier A, Eisenberg R. Efficient Catalysis of Nazarov Cyclization Using a Cationic Iridium Complex Possessing Adjacent Labile Cooridnation Sites. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 126: 6864-6865, 2004

Abstract The dicationic Ir(III) complex [IrMe(CO)(dppe)(DIB)](BARF)2 having adjacent labile sites has been found to be a very effective catalyst for promoting the Nazarov cyclization of aryl vinyl and divinyl ketones. Spectroscopic evidence for a substate-catalyst complex before cyclization is presented. The efficiency of the cyclization is attributed to the electrophilicity of the Ir(III) complex and substrate activation via chelation.......