title: Multiple and Highly Selective Alkyne-Isonitrile C-C and C-N Couplings at Group 4 Metallocenes.
abstract: Reactions of the group 4 metallocene alkyne complexes [Cp'2 M(η(2) -Me3 SiC2 SiMe3 )] [Cp'2 =rac-(ebthi)=rac-1,2-ethylene-1,1'-bis(η(5) -tetrahydroindenyl): M=Ti, Zr, Hf; Cp'2 =Cp*2 (Cp*=η(5) -pentamethylcyclopentadienyl): M=Zr] with 2,6-dimethylphenyl isocyanide (2-xylyl isonitrile, XyNC) were investigated. Depending on the metal, the Cp' ligand, and/or the stoichiometry, as well as the reaction temperature and time, different products were obtained. The products included simple end-on coordination compounds of XyNC in addition to those of the coupling of Me3 SiC2 SiMe3 with two, three, or four isonitriles to form enimine complexes, aza-metallacycloallenes, and fused heterocyclic systems, respectively. One example of the latter tricyclic compounds was subject to demetalation by using HCl. Molecular structures of the heterometallacycles were determined by X-ray crystallography. The interconversion of the products was investigated by (1) H NMR spectroscopy.
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
authors.forename: Kai
authors.initials: K
authors.lastname: Altenburger
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
authors.forename: Perdita
authors.initials: P
authors.lastname: Arndt
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
authors.forename: Lisanne
authors.initials: L
authors.lastname: Becker
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
authors.forename: Fabian
authors.identifier: http://orcid.org/0000-0002-1119-0343
authors.initials: F
authors.lastname: Reiß
authors.affiliation: A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov St. 28, 119991, Moscow, Russia.
authors.forename: Vladimir V
authors.initials: VV
authors.lastname: Burlakov
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
authors.forename: Anke
authors.initials: A
authors.lastname: Spannenberg
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baumann
authors.affiliation: Leibniz-Institut für Katalyse e.V. an der, Universität Rostock, Albert-Einstein-Straße 29a, 18059, Rostock, Germany. uwe.rosenthal@catalysis.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Rosenthal
keywords: C−C coupling reactions; alkynes; fused-ring systems; isocyanide; metallocenes