title: Palladium-catalyzed decarboxylative [4 + 3] cyclization of gamma-methylidene-delta-valerolactones with 1,1-dicyanocyclopropanes.
abstract: A palladium-catalyzed decarboxylative [4 + 3] cyclization of gamma-methylidene-delta-valerolactones with 1,1-dicyanocyclopropanes has been developed to produce cycloheptane derivatives in a convergent manner. This method can be applied to the synthesis of azepanes by reacting with aziridines, and their asymmetric variants have also been described. In addition, selective ring-expansion reactions can be achieved for certain gamma-methylidene-delta-valerolactones to give nondecarboxylated nine-membered lactones.
authors.affiliation: Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan. shintani@kuchem.kyoto-u.ac.jp
authors.forename: Ryo
authors.initials: R
authors.lastname: Shintani
authors.forename: Masataka
authors.initials: M
authors.lastname: Murakami
authors.forename: Takaoki
authors.initials: T
authors.lastname: Tsuji
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tanno
authors.forename: Tamio
authors.initials: T
authors.lastname: Hayashi
mesh_terms: D001388:Aziridines / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D003508:Cycloheptanes / Q000138:chemical synthesis* / Q000737:chemistry; D007783:Lactones / Q000138:chemical synthesis / Q000737:chemistry*; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry*; D011753:Pyrones / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D001388:Aziridines; D003508:Cycloheptanes; D007783:Lactones; D011753:Pyrones; C052207:delta-valerolactone; D010165:Palladium; C037556:gamma-valerolactone