A green and convenient approach for the one-pot solvent-free synthesis of coumarins and β-amino carbonyl compounds using Lewis acid grafted sulfonated carbon@titania composite
Superparamagnetic Fe3O4is shown to act as a very efficient catalyst for the one-pot, three-component synthesis of 5,5-disubstituted hexahydropyrimidines and their spiropiperidines. The catalyst is easily recovered by the use of an external magnet and reused in several reactions without any noticeable loss of activity. The products are obtained in short time and good purity upon separation of the catalyst and evaporation of the volatiles of the reaction mixture.
Catalytic potential of ammonium hypobromite in the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones from Biginelli-type condensation reaction between an aldehyde, β-keto ester and urea has been explored. The reaction proceeds under solvent-free conventional heating as well as microwave-irradiation conditions to afford the respective products in excellent yields.
Superparamagnetic Iron Oxide as an Efficient Catalyst for the One-Pot, Solvent-Free Synthesis of 5,5-Disubstituted Hexahydropyrimidines and Their Spiro Analogues
