X‐ray Crystal Structure of an Alkene–Pentacarbonyldicobalt–Alkyne Complex: Isolation of a Stable Magnus‐Type Pauson–Khand Reaction Intermediate

Caught in the act: The [(dibenzosuberenol)Co2(CO)6] cluster 1 (see scheme) loses a carbonyl ligand to yield 2, the first structurally characterized alkyne–dicobaltpentacarbonyl–alkene complex. This finding provides experimental support for the first step of the proposed mechanism of the Pauson–Khand reaction and yields crucial structural data relevant to computational studies of the process.