Tungsten-substituted molybdophosphoric acid impregnated with kaolin: effective catalysts for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones via biginelli reaction

In this paper, synthesize tungsten-substituted molybdophosphoric acid (H3PMo7W5O40·24H2O) and impregnated with kaolin clay by wetness impregnation method. The catalytic activity explored for synthesis of 3,4-dihydropyrimidin-2(1H)-ones (DHPM) via Biginelli reaction.

Acetylation of Eugenol over 12-Molybdophosphoric Acid Anchored in Mesoporous Silicate Support Synthesized from Flint Kaolin

A new prepared catalyst, 12-molybdophosphoric acid (HPMo) anchored to the mesoporous aluminosilicate AlSiM, synthesized from Amazon kaolin, was characterized and used as a heterogeneous acid catalyst for the production of eugenyl acetate by acetylation of eugenol with acetic anhydride. The effect of various reaction parameters, such as catalyst concentration, eugenol/acetic anhydride molar ratio, temperature and reaction time, was studied to optimize the conditions of maximum conversion of eugenol. The kinetics studies showed that in eugenol acetylation, the substrate concentration follows a first order kinetics. The results of activation energy was 19.96 kJ mol−1 for HPMo anchored to AlSiM. The reuse of the catalyst was also studied and there was no loss of catalytic activity after four cycles of use (from 99.9% in the first cycle to 90% in the fifth cycle was confirmed), and an excellent stability of the material was observed. Based on catalytic and kinetic studies, HPMo anchored to AlSiM is considered an excellent catalyst.

12-Molybdophosphoric acid anchored on aminopropylsilanized magnetic graphene oxide nanosheets (Fe3O4/GrOSi(CH2)3–NH2/H3PMo12O40): a novel magnetically recoverable solid catalyst for H2O2-mediated oxidation of benzylic alcohols under solvent-free conditions

12-Molybdophosphoric acid was anchored on magnetic aminopropylsilanized graphene oxide nanosheets and used as a magnetically recoverable catalyst for solvent-free selective oxidation of benzylic alcohols into the carbonyl compounds with H2O2.