One-pot acetalizations of cyclohexanone. acetophenone and benzophenone were carried out using methanol over H-montmorillonite clay
(a mesoporous material). silica, alumina, and different zeolites such as HFAU-Y.HBeta, H-ZSM-5, and H-mordenite. In all the cases a single
product-the corresponding dimethylacetal-was obtained in high yields. Hemiacetal formation was not observed with any catalyst. A
comparison of catalytic activity indicated that montmorillonite K-10 is the most active catalyst for the reaction. As evidenced by the reaction
time studies, the catalyst decay is greater over the zeolite catalyst than over the clay.
Kannan, V; Dr. Sreekumar, K(Cochin University of Science & Technology, August , 2011)
[+]
[-]
Abstract:
Catalysis is a technologically important field which determines the quality of life in future. Catalyst research in pharmaceutical industry,fine chemical synthesis and emission control demands supported catalysts in bulk quantities.In the present work it was observed that clay supported catalysts mentioned in various chapters could also be used for the synthesis of similar molecules. The K10Ti catalyst can be used for the synthesis similar substituted imidazole derivatives under solvent free conditions and synthetically important Mannich bases of substrates containing various substitutes.Al-pillared saponite can be used for acetalation of other polyhydroxy compounds like glycerol,mannitol etc.Cu-Pd KSF catalyst has found application in C-C bond forming reactions which can be applied to other reactions and similar methods can be adopted for the synthesis of other catalyst by changing the transition metals. Montmorillonite K10 catalysed synthesis of triarylpyridines can be extended to the synthesis tetrasubstuted pyroles.K10Ti can also be utilized for the synthesis of similar heterocycles.
Description:
Dept.of Applied Chemistry,Cochin University of Science and Technology
Binitha, N N; Dr.Sugunan, S(Cochin University of Science and Technology, October , 2006)
[+]
[-]
Abstract:
Green chemistry boots eco-friendly,natural clays as catalysts in the chemical as well as in the pharmaceutical industry.Industry demands thermal stability,mechanical strength etc for the catalyst and there the modification methods becomes important.Pillaring tunes clays as efficient catalytic templates for shape selective organic synthesis.Here pillared clays are used as promising alternatives for the environmentally hazardous homogeneous catalysts in some industrially important Friedel-Crafts alkylation reactions of arenes with lower alchohols and higher olefins.The layer structure is enhanced upon pillaring and allows the nanocomposite formation with polyaniline to develop today’s nanoscale diameter devices.Present work gives an entry of pillared clays to the world of conducting composite nanofibers.
Description:
Department of Applied Chemistry,
Cochin University of Science and Technology