title: Cp*RuCl-catalyzed [2 + 2 + 2] cycloadditions of alpha,omega-diynes with electron-deficient carbon-heteroatom multiple bonds leading to heterocycles.
abstract: In the presence of a catalytic amount of Cp*RuCl(cod), 1,6-diynes were allowed to react chemo- and regioselectively with electron-deficient nitriles and heterocumulenes at 60-90 degrees C to afford heterocyclic compounds. The mechanism of the ruthenium-catalyzed regioselective formations of bicyclic pyridines and pyridones were analyzed on the basis of density functional calculations. Cyclocotrimerizations of ethyl propiolate with ethyl cyanoformate or propyl isocyanate gave rise to two of the four possible pyridine or pyridone regioisomers.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan. yamamoto@apchem.nagoya-u.ac.jp
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kinpara
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Saigoku
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Takagishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Okuda
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishiyama
authors.forename: Kenji
authors.initials: K
authors.lastname: Itoh