Current Microwave Chemistry - Volume 1, Issue 2, 2014

In this paper, we report on a new procedure for nanocrystalline titania synthesis using microwave-assisted homogeneous hydrolysis under hydrothermal conditions. We show that this synthetic procedure promotes formation of low-aggregated TiO2 powders with very high specific surface area (up to 240 m2–/g) and small particle size (5-7 nm), and that it hinders SO2 2– ions’ sorption on the surface of nanoparticles.

In this study aza-Michael addition reactions were used as a Green chemistry protocol to synthesize propanenitrile derivatives. The reactions were performed in both presence and absence of lipases, under orbital shaking and microwave irradiation, using water as a protic solvent and hexane as an aprotic solvent. aza-Michael adducts were synthesized with acceptable yields, under microwave irradiation and water as solvent in th Read More

Bismuth nitrate-catalyzed microwave-assisted one-pot three components Aza-Diels-Alder reaction has been investigated. This method has been used for an efficient synthesis of 2-azabicyclo[2,2,2] cyclooctanones.

A microwave-assisted reaction is developed to facilitate the construction of 1,2-dihydro[1,6]naphthyridines from methyl ketones, amines and malononitrile. This one-pot, catalyst-free, solvent-free, pseudo-five-component synthesis of [1,6]naphthyridines involves a sequential Knoevenagel reaction, Michael addition, ring closure and cyclizationaromatization cascades. The advantages of this method lie in its simplicity, cost ef Read More

An efficient, one-pot, solvent-free synthesis of ethyl 3,5-disubstituted-1H-pyrrole-2-carboxylate is achieved by a reaction of 1,3-disubstituted propen-2-one and ethylnitroacetate, in presence of diethylamine (Et2NH) and triethylphosphite (P(OEt)3) under microwave (MW) irradiation via cascade Michael-reductive cyclization. The mechanistic outcome of the reaction has also been described. This protocol establishes an e Read More

A small library of twenty-two 3,4-dihydropyrimidin-2(1H)-ones and twenty-one thiones was synthesized under microwave irradiation using acetic acid as both solvent and catalyst. The oxidation of 3,4-dihydropyrimidin-2(1H)-ones to the corresponding pyrimidin-2(1H)-ones was systematically studied with heterogeneous and homogeneous oxidants. Microwave- assisted oxidation using potassium peroxydisulfate in an acetonitril Read More

The regio- and diastereoselective base catalyzed one-pot, multicomponent reaction of 4-hydroxycoumarin, aldehyde, and 2-bromo-1-phenylethanone giving trans 2,3-dihydrofuro[3,2-c]coumarins is greatly accelerated by a combination of 4-(N,N-dimethylamino)pyridine (DMAP) and microwave heating. The classical thermal reaction takes a long reaction time and uses environment unfriendly bases, pyridine, NaOH. T Read More

Novel solid-supported catalysts derived from palladium supported on silicon carbide were prepared. The resulting catalysts produced high methyl cinnamate yields (>80%) for more than 20 cycles of the Heck reaction of iodobenzene and methyl acrylate. The use of microwave heating during catalyst preparation was found to significantly improve the catalytic activity compared with conventional heating. This result is interpret Read More

A series of new imines of 7-Aminocephalosporinic acid (7-ACA) were synthesized by fragment-based design using smaller and functionally simpler adducts like alpha-halo ketones, N-heterocycles and 7-ACA with good success to generate chemical compounds with drug-like properties effective against Staphylococcus aureus and Pseudomonas aeruginosa which are resistant to several antibiotics and are responsible for a large n Read More

Microwave radiation, an electromagnetic radiation, is widely used as a source of heating in organic synthesis. Since the discovery of the microwave heating approach, microwave-assisted reaction has emerged as a new green-method in organic synthesis as it provides fast, higher yields, and higher product purities, and it reduces pollution of the environment. The purine ring system possesses undisputed biological importance Read More