title: Selective syntheses of metalated pyridines from two different unsymmetrical acetylenes, a nitrile, and a titanium(II) alkoxide.
abstract: Cyclotrimerization of two different, unsymmetrical acetylenes and p-toluenesulfonylnitrile with a divalent titanium alkoxide reagent, Ti(O-i-Pr)4/2 i-PrMgCl, yielded single pyridyltitanium compounds in a highly selective manner. These metalated pyridines were confirmed by deuteriolysis to give the corresponding deuterated pyridines and underwent iodinolysis and copper-catalyzed alkylation to demonstrate their synthetic utility. Alternatively, a different type of cyclotrimerization of an alkynamide, terminal acetylenes, and alpha-alkoxynitriles mediated by the same titanium(II) alkoxide again proceeded in a highly selective manner to give single pyridines having a titanated side chain.
authors.affiliation: Department of Biomolecular Engineering, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8501, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Suzuki
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Tanaka
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Urabe
authors.forename: Fumie
authors.initials: F
authors.lastname: Sato