title: Ruthenium-catalyzed cycloaddition of 1,6-diynes and nitriles under mild conditions: role of the coordinating group of nitriles.
abstract: In the presence of a catalytic amount of [Cp*RuCl(cod)] (Cp*=pentamethylcyclopentadienyl, cod=1,5-cyclooctadiene), 1,6-diynes were allowed to react chemo- and regioselectively with nitriles bearing a coordinating group, such as dicyanides or alpha-halonitriles, at ambient temperature to afford bicyclic pyridines. Careful screening of nitrile components revealed that a C[triple chemical bond]C triple bond or heteroatom substituents, such as methoxy and methylthio groups, proved to act as the coordinating groups, whereas C==C or C==O double bonds and amino groups failed to promote cycloaddition. This suggests that coordinating groups with multiple pi-bonds or lone pairs are essential for the nitrile components.
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: Ryuji
authors.initials: R
authors.lastname: Ogawa
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishiyama
authors.forename: Kenji
authors.initials: K
authors.lastname: Itoh
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D002384:Catalysis; D009570:Nitriles / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis*; D012428:Ruthenium / Q000737:chemistry
chemical_list: D000480:Alkynes; D009570:Nitriles; D009942:Organometallic Compounds; D011725:Pyridines; D012428:Ruthenium