The Synthesis, Characterization, Applications Of Biscyclopentadiene Titanium Bisperfluorooctanesulfonate

A number of organic titanium compounds serve as Lewis acid catalysts in Organic synthesis. Normally, their Lewis acid is too mild to form carbon-carbon bond. at the same time, some organic titanium compounds sensitive to water, Hence, the increase of the Lewis acidity of organic titanium compounds is of prime importance to expand the scope of their synthetic utility. One of the useful means for this purpose is to attach electron-withdrawing group(s) on titanium. Perfluoroalk- ylsulfonate is such an electron-withdrawing group. It's reported that trifluoromethy- lsulfonic titanium can catalyze carbon-carbon bond-forming reactions effectively. However their hygroscopic nature did not allow us to fully characterize the structure of these compounds. And it's reported perfluorooctanesulfonate metal compounds are air-stable and water-stable compound. In this paper, we synthesize and characterize Biscyclopentadiene titanium bisperfluorooctanesulfonate compound. Furthermore, its catalytic activity is assessed in the carbon-carbon bond-forming reactions. The contents of the paper include five parts:(1) Biscyclopentadiene titanium bisperfluorooctanesulfonate was synthesized using AgOSO2C8F17 and Cp2TiCl2, the yield of which is up to 85%. The product was analysized by 1H NMR and 19F NMR, and the stability of which was studied in air and water, as well as the solubility in organic solvent.(2)The catalytic activity of Biscyclopentadiene titanium bisperfluorooctane- sulfonate was assessed in esterification. It's found that the catalyst can induce the reaction of aromatic alcohol and acetic anhydride rapidly at room temperature, but induce the reaction of long-fatty alcohol and acetic anhydride at higher temperature. The yield of the reaction is up to 90% and the catalyst can be used repeatedly.(3) The catalytic activity of Biscyclopentadiene titanium bisperfluorooctane- sulfonate was assessed in allylation, viz. the reaction of aromatic aldehyde and tetraallylstannane. A series of unsaturated aromatic alcohol were synthesized, the yield of which is up to 80%. Meanwhile the amount of the catalyst and the solvent were studied.(4) The catalytic activity of Biscyclopentadiene titanium bisperfluorooctane- sulfonate was assessed in Mukaiyama-Aldol reaction(aromatic aldehyde and trimethylsilane). A series of aromatic alcohol compounds were synthesized in nitrogen gas, at room temperature. The products were easy separated from catalyst, and the yield of which is up to 82%.(5) The catalytic activity of Biscyclopentadiene titanium bisperfluorooctane- sulfonate was assessed in Friedel-Crafts reaction. Aromatic oxide and acetyl chloride were heated and stirred for 3-8h, then the mixture was subjected to the column chromatograph on silica gel immediately. The product(yield is about 55%) was obtained.