Alkynones react with arylboronic acids in the presence of a rhodium(I) catalyst to afford four- and five-membered-ring cyclic alcohols equipped with a tetrasubstituted exocyclic olefin. The cyclic allylic alcohol skeleton is constructed by the carbon-carbon bond formation between the carbonyl group and an alkenylrhodium(I) intermediate formed by the regioselective addition of an arylrhodium(I) species across the carbon-carbon triple bond. (c) 2007 Elsevier Ltd. All rights reserved.
Acyl 1,3-Migration in Rhodium-Catalyzed Reactions of Acetylenic β-Ketoesters with Aryl Boronic Acids: Application to Two-Carbon-Atom Ring Expansions