Chiral electron deficient ruthenium helical coordination polymer as a catalyst for the epoxidation of substituted styrenes

An air and moisture stable ruthenium(Ⅲ) formate complex Ru(HCO2)Cl2]n has been synthesized and examined in the epoxidation of substituted styrenes. X-ray crystallographic data of this complex were determined and showed that the formate ligand coordinates to the ruthenium centers in μ2-η2 fashion (syn, syn). Its asymmetric unit contains one Ru(Ⅲ) ion together with the half of a formate ligand and one chloride anion, which are bridged between the metal centers, forming a 1-D chain coordination polymer. This electron deficient helical coordination polymer was employed in the epoxidation of parafluorostyrene, affording the epoxide product in 92% yield. Natural chirality of this coordination polymer is applicable in asymmetric epoxidation reactions.