• Media type: E-Article
  • Title: Unusual Nitrile–Nitrile and Nitrile–Alkyne Coupling of FcCN and FcCCCN
  • Contributor: Becker, Lisanne; Strehler, Frank; Korb, Marcus; Arndt, Perdita; Spannenberg, Anke; Baumann, Wolfgang; Lang, Heinrich; Rosenthal, Uwe
  • imprint: Wiley, 2014
  • Published in: Chemistry – A European Journal
  • Language: English
  • DOI: 10.1002/chem.201304478
  • ISSN: 0947-6539; 1521-3765
  • Keywords: General Chemistry ; Catalysis ; Organic Chemistry
  • Origination:
  • Footnote:
  • Description: <jats:title>Abstract</jats:title><jats:p>The reactions of the Group 4 metallocene alkyne complexes, [Cp*<jats:sub>2</jats:sub>M(η<jats:sup>2</jats:sup>‐Me<jats:sub>3</jats:sub>SiC<jats:sub>2</jats:sub>SiMe<jats:sub>3</jats:sub>)] (<jats:bold>1 a</jats:bold>: M=Ti, <jats:bold>1 b</jats:bold>: M=Zr, Cp*=η<jats:sup>5</jats:sup>‐pentamethylcyclopentadienyl), with the ferrocenyl nitriles, FcCN and FcCCCN (Fc=Fe(η<jats:sup>5</jats:sup>‐C<jats:sub>5</jats:sub>H<jats:sub>5</jats:sub>)(η<jats:sup>5</jats:sup>‐C<jats:sub>5</jats:sub>H<jats:sub>4</jats:sub>)), is described. In case of FcCN an unusual nitrile–nitrile CC homocoupling was observed and 1‐metalla‐2,5‐diaza‐cyclopenta‐2,4‐dienes (<jats:bold>3 a</jats:bold>, <jats:bold>b</jats:bold>) were obtained. As the first step of the reaction with <jats:bold>1 b</jats:bold>, the nitrile was coordinated to give [Cp*<jats:sub>2</jats:sub>Zr(η<jats:sup>2</jats:sup>‐Me<jats:sub>3</jats:sub>SiC<jats:sub>2</jats:sub>SiMe<jats:sub>3</jats:sub>)(NC‐Fc)] (<jats:bold>2 b</jats:bold>). The reactions with the 3‐ferrocenyl‐2‐propyne‐nitrile FcCCCN lead to an alkyne–nitrile CC coupling of two substrates and the formation of 1‐metalla‐2‐aza‐cyclopenta‐2,4‐dienes (<jats:bold>4 a</jats:bold>, <jats:bold>b</jats:bold>). For M=Zr, the compound is stabilized by dimerization as evidenced by single‐crystal X‐ray structure analysis. The electrochemical behavior of <jats:bold>3 a</jats:bold>, <jats:bold>b</jats:bold> and <jats:bold>4 a</jats:bold>, <jats:bold>b</jats:bold> was investigated, showing decomposition after oxidation, leading to different redox‐active products.</jats:p>