title: Why is tetrazole formation by addition of azide to organic nitriles catalyzed by zinc(II) salts?
abstract: The mechanism by which zinc(II) catalyzes the union of an azide ion with organic nitriles to form tetrazoles is investigated by means of density functional theory using the hybrid functional B3LYP. The calculations indicate that coordination of the nitrile to the zinc ion is the dominant factor affecting the catalysis; this coordination substantially lowers the barrier for nucleophilic attack by azide. Relative reaction rates of catalyzed and uncatalyzed tetrazole formation also provide experimental support for this conclusion.
authors.affiliation: Department of Molecular Biology, TPC-15, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Fahmi
authors.initials: F
authors.lastname: Himo
authors.forename: Zachary P
authors.initials: ZP
authors.lastname: Demko
authors.forename: Louis
authors.initials: L
authors.lastname: Noodleman
authors.forename: K Barry
authors.initials: KB
authors.lastname: Sharpless
mesh_terms: D001386:Azides / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D008958:Models, Molecular; D009570:Nitriles / Q000737:chemistry*; D013777:Tetrazoles / Q000138:chemical synthesis* / Q000737:chemistry; D015032:Zinc / Q000737:chemistry*
chemical_list: D001386:Azides; D009570:Nitriles; D013777:Tetrazoles; C045574:1H-tetrazole; D015032:Zinc