Stereochemical and mechanistic features of asymmetric Pauson-Khand processes

The absolute stereochemical configurations of a series of optically pure al kyne-Co-2(CO)(5)PPh3 complexes and their corresponding cyclopentenones, der ived from Pauson-Khand reaction with norbornene, have been established; an X-ray crystal structure of an optically pure cyclopentenone has facilitated this study. In turn, this has led to the unambiguous determination of the site of decarbonylation and alkene complexation when such monophosphine com plexes are utilised in asymmetric Pauson-Khand processes.