Application Of Solid Base Catalyst On Synthesis Of Ferrocene Derivatives

As the green chemistry penetrate deeply in the explore of new type catalysts, people are paying more and more attention to their application in chemical reactions. New type catalysts contain solid acid catalysts,solid base catalysts,metal catalysts, etc. These catalysts not only give high catalytic activity and selecivity,allow easier separation,recovery and recycling, but also have no corrosion to facilities,reduce environmental pollutions. So they are accepted as important research content of future green chemistry.In this paper, solid bases cat-5-p,cat-10-p,cat-15-p and cat-20-p were prepared by a simple sol-gel process with tetraethyl orthosilicate(TEOS) and aminopropyltriethoxysilane(APTES) under strong acid condition. The materials were used to catalyze the Knoevenagel condensation reaction between formylferrocene and ethyl malonate,the Claisen-Schmidt condensation between formylferrocene and acetophenone, also and para substituted derivatives of acetophenone. The results showed that cat-5-p and cat-10-p had better catalytic activity. Take cat-10-p as an example, when it was used in above two reactions, the productivity is 90.2(for 30 min) and 81.97%(4.5h). The influence of the para substituting groups and different dose of reactants was also investigated. Finally, take research on the reusage of more efficient cat-10-p and it was seen having good activity after the 5th use time.Make sure the BET specific surface, pore structure and pore size distribution(PSD) of solid bases on the base of their N₂ adsorption-desorption isothems. The materials were also characterized by IR spectra, ²⁹Si MAS NMR, ¹³C CP MAS NMR, TG-DTA measurements. It was proved that cat-5-p and cat-10-p contained larger number of mesopores with narrow pore size distribution in the range of 3-4nm and have better catalytic activity than that of cat-15-p,cat-20-p,cat-25-p. It was found that their pore volume was decreasing with the increase of x(mol fraction) of APTES in solid bases, so the PSD and pore volume was significate to catalysts' activity. The materials have bad thermal stability through the analysis of TG-DTA measured curve, and it was not suitable for the reactions at high temperature.