Access to Highly Functionalized Cyclopentenones via Diastereoselective Pauson Khand Reaction of Siloxy-Tethered 1,7-Enynes

A diastereoselective Co2(CO)8-mediated Pauson-Khand reaction (PKR) of siloxy-tethered 1,7-enynes for the synthesis of cyclopentaoxasilinones has been developed. This transformation can be performed on a multi-gram scale and is characterized by broad substrate scope, functional group compatibility, and high chemo- and diastereoselectivity. Oxidation of the resulting cyclopentaoxasilinones delivers stereoenriched β-alkylated cyclopentenones, which are inaccessible by intermolecular PKRs. This research provides a practical solution to the challenges associated with the classical intermolecular PKR.