title: Low-valent niobium-catalyzed intermolecular [2 + 2 + 2] cycloaddition of tert-butylacetylene and arylnitriles to form 2,3,6-trisubstituted pyridine derivatives.
abstract: A catalytic system based on low-valent niobium has been developed, consisting of NbCl5, Zn, and an alkoxysilane. This combination has been shown to be an efficient catalyst for the synthesis of pyridine derivatives from the intermolecular cycloaddition of alkynes and nitriles via a niobacyclopentadiene intermediate.
authors.affiliation: Department of Chemistry and Materials Engineering, Faculty of Chemistry, Materials and Bioengineering, Kansai University, Suita, Osaka 564-8680, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Satoh
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Obora
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D009556:Niobium / Q000737:chemistry*; D009570:Nitriles / Q000737:chemistry*; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D009570:Nitriles; D011725:Pyridines; D009556:Niobium; D000114:Acetylene