68977-52-6Relevant academic research and scientific papers
CONCLUSIVE EVIDENCE AGAINST A CYVLOBUTADIENE INTERMEDIATE IN THE CYCLOTRIMERIZATION OF DIARYLACETYLENE USING THE DIARYLACETYLENE HEXACARBONYL DICOBALT COMPLEX AS CATALYST
Pepermans, Henri,Willem, Rudolph,Gielen, Marcel,Hoogzand, Cornelis
, p. 115 - 126 (2007/10/02)
To decide whether the cyclotrimerization of diarylacetylene with diarylacetylene hexacarbonyl dicobalt as catalyst, proceeds via a cyclobutadiene intermediate, two experiments were performed, both reliyng on the experimentally verified hypothesis that a 3-methoxyphenyl ring can be considered as an ideally chemically laballed phenyl ring : (1) the cyclotrimerization of diphenylacetylene with bis(3-methoxyphenyl)acetylene, and (2) the cyclotrimerization of 1-(3-methoxyphenyl)-2-phenylacetylene.Analysis of the resulting meta methoxy substituted hexaphenylbenzenes using our chemical shift model, is for both experiments conclusive against the involvement of a cyclobutadiene intermediate.
