Chemo- and regioselective cyclohydrocarbonylation of alpha-keto alkynes catalyzed by a zwitterionic rhodium complex and triphenyl phosphite

alpha-Keto alkynes react with CO and H-2 in the presence of catalytic quant ities of the zwitterionic rhodium complex (eta(6)-C6H5BPh3)Rh--(+)(1,5-COD) and triphenyl phosphite affording either the 2-, 2(3H)-, or 2(5H)-furanone s in 61-93% yields. The cyclohydrocarbonylation is readily accomplished usi ng substrates containing alkyl, aryl, vinyl, and alkoxy groups at the acety lenic terminal, as well as a variety of primary, secondary, and tertiary al kyl, aryl, and heteroaryl groups connected to the ketone functionality. Str uctural and electronic properties present in the starting materials mediate the chemo- and regioselectivity of the reaction.