Preparation of Optically Active cis-Cyclopropane Carboxylates: Cyclopropanation of α‑Silyl Stryenes with Aryldiazoacetates and Desilylation of the Resulting Silyl Cyclopropanes

Optically active cis-cyclopropane carboxylates are prepared via the Rh₂(S-PTAD)₄-catalyzed cyclopropanation of α-silyl styrenes with aryl diazoacetates followed by desilylation of the resulting silyl cyclopropane carboxylates. The conjugation of the aryl ring with CC bond and π stacking are proposed for the stereoselectivity of cyclopropanation, and configuration inversion is observed with the desilylation process.