title: Nickel-catalyzed intermolecular alkyne insertion into cyclobutanones.
abstract: Cyclobutanones reacted with alkynes in the presence of nickel(0) catalysts to produce cyclohexenones. Oxidative cyclization of the carbonyl group of the cyclobutanone and the alkyne with the nickel(0) was followed by beta-carbon elimination from the resulting oxanickelacyclopentene and subsequent reductive elimination. This reaction achieves a formal alkyne insertion between the carbonyl carbon and the alpha-carbon, providing a six-membered carbocyclic skeleton.
authors.affiliation: Department of Synthetic Chemistry and Biological Chemistry, Kyoto University, Katsura, Kyoto 615-8510, Japan. murakami@sbchem.kyoto-u.ac.jp
authors.forename: Masahiro
authors.initials: M
authors.lastname: Murakami
authors.forename: Shinji
authors.initials: S
authors.lastname: Ashida
authors.forename: Takanori
authors.initials: T
authors.lastname: Matsuda