Insight into the Reactivity of Olefins in the Pauson­Khand Reaction.

The reactivity of different Co2(CO)6-acetylene complexes in the Pauson­Khand reaction is strongly dependent on the nature of the olefin. Theoretical calculations at both the DFT and ONIOM levels are concordant with experimental observations and suggest how the olefin-cobalt interactions in the complex could have a major effect on the relative reactivity of the olefins. This study rationalizes for the first time the experimentally observed reactivity differences of cyclohexene, cyclopentene, and norbornene. [ABSTRACT FROM AUTHOR]