A stable catalyst of the Pauson–Khand annelation

A practical catalytic-in-cobalt version of the PKA is clearly a desirable objective and there has been much research towards this goal in recent years. Systems developed to date, however, require either the use of high temperatures and high carbon monoxide pressures and/or the use of the sensitive cobalt catalyst, octacarbonyldicobablt(0). We report here a detailed account of PKA results obtained using the more robust cobalt compound, heptacarbonyl(triphenylphosphine)dicobalt(0), , which indicate that 1 is an attractive alternative to octacarbonyldicobalt(0) as a catalyst of the PKA.