title: Rapid ruthenium-catalyzed synthesis of pyranopyrandiones by reconstructive carbonylation of cyclopropenones involving C[bond]C bond cleavage.
abstract: Pyranopyrandiones were prepared by a novel ruthenium-catalyzed carbonylative dimerization of cyclopropenones via C-C bond cleavage. For example, treatment of dipropylcyclopropenone with a catalytic amount of Ru3(CO)12 and NEt3 in THF under 15 atm of carbon monoxide at 140 degrees C for 20 h gave a novel functional monomer, 3,4,7,8-tetrapropylpyrano[6,5-e]pyran-2,6-dione, in an isolated yield of 81%. Unsymmetrically substituted pyranopyrandiones were also obtained by ruthenium-catalyzed carbonylative coupling of cyclopropenones with alkynes under similar reaction conditions.
authors.affiliation: Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Kondo
authors.forename: Yushi
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Taguchi
authors.forename: Ayako
authors.initials: A
authors.lastname: Nakamura
authors.forename: Takumi
authors.initials: T
authors.lastname: Okada
authors.forename: Masashi
authors.initials: M
authors.lastname: Shiotsuki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ura
authors.forename: Kenji
authors.initials: K
authors.lastname: Wada
authors.forename: Take-aki
authors.initials: TA
authors.lastname: Mitsudo