title: An efficient method for cyclopentene annulation onto alpha,beta-unsaturated ketones: W(CO)(5)(L)-catalyzed 5-endo-dig cyclization of 6-siloxy-5-en-1-ynes.
abstract: [reaction: see text] A highly efficient method for the cyclopentene annulation onto alpha,beta-unsaturated ketones is described. Indium-mediated 1,4-propargylation onto alpha,beta-unsaturated ketones in the presence of tert-butyldimethylsilyl triflate and dimethyl sulfide gives the 6-siloxy-5-en-1-yne derivatives, which undergo W(CO)(5)(L)-catalyzed 5-endo-dig cyclization to give the corresponding cyclopentene derivatives in good yield.
authors.affiliation: Department of Chemistry, Tokyo Institute of Technology, O-okayama, Meguro-ku, Japan. niwasawa@chem.titech.ac.jp
authors.forename: Nobuharu
authors.initials: N
authors.lastname: Iwasawa
authors.forename: Tomoya
authors.initials: T
authors.lastname: Miura
authors.forename: Koichi
authors.initials: K
authors.lastname: Kiyota
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusama
authors.forename: Kooyeon
authors.initials: K
authors.lastname: Lee
authors.forename: Phil Ho
authors.initials: PH
authors.lastname: Lee