The Role of [η2-Bis(tert-butylsulfonyl)acetylene](carbonyl)(η5-cyclopentadienyl)cobalt(I) as an Intermediate in the Alkyne Dimerisation

✍ Scribed by Tobias H. Staeb; Jorge Chávez; Rolf Gleiter; Bernhard Nuber

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 108 KB
• Volume: 2005
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200500394

✦ Synopsis

Abstract

Dicarbonyl(η^5^‐cyclopentadienyl)cobalt(I) (1) reacts with the electron‐poor alkyne bis(tert‐butylsulfonyl)acetylene to give the corresponding cyclobutadiene complex 6, whereas the reaction of [CpCo(CO)~2~] with dimethyl acetylenedicarboxylate yields the cyclopentadienone complex 7 under the same conditions. The cyclobutadiene complex 6 could not be obtained by the treatment of η^2^‐bis(tert‐butylsulfonyl)acetylene(η^5^‐cyclopentadienyl)cobalt(I) [3(H)] with an excess of bis(tert‐butylsulfonyl)acetylene. The same holds for the treatment of 3(H) with dimethyl acetylenedicarboxylate and bis(catecholatoboryl)acetylene. With these results we assume that the monoalkyne complex 3(H) is not an intermediate in the alkyne oligomerisation of electron‐poor alkynes, as was shown for electron‐rich ones. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)