Synthesis and structure of an air-stable bis(isopropylcyclopentadienyl) zirconium perfluorooctanesulfonate and its catalyzed benzylation of 1,3-dicarbonyl derivatives with alcohols

An air-stable uninuclear complex of bis(isopropylcyclopentadienyl) zirconium perfluorooctane sulfonate (1a·H2O·3THF) was successfully synthesized by the reaction of (i-PrCp)2ZrCl2 with C17SO3Ag. The compound 1a·H2O·3THF was characterized by different techniques (such as X-ray single crystal diffraction, TG-DSC, conductivity measurement and acid strength) and found to have the similar nature of water tolerance, air-stability, thermally-stability and strong Lewis-acidity with that of our previously reported binuclear and uninuclear zirconocenes perfluorooctanesulfonate. This novel complex was confirmed to be an effective catalyst with good recyclability and reusability for the direct benzylation of 1,3-dicarbonyl derivatives using alcohols as alkylating agents. Various 1,3-dicarbonyl and alcohols derivatives can participate in the reaction, affording the corresponding monobenzylated products in competitive yields as compared to its counterparts, such as Cp2Zr(OSO17)2·3H2O·THF and the traditional Lewis-acid catalysts.

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