A chemical placebo: NaCl as an effective, cheapest, non-acidic and greener catalyst for Biginelli-type 3,4-dihydropyrimidin-2(1H)-ones (-thiones) synthesis

An efficient green protocol for the preparation of acetoacetamides and application of the methodology to a one-pot synthesis of Biginelli dihydropyrimidines. Expansion of dihydropyrimidine topological chemical space

A one pot synthesis of Biginelli dihydropyrimidines. The novel use of the amino acids allows topological diversification of the chemical space.

Selective reduction of nitro-compounds to primary amines by nickel-catalyzed hydrosilylative reduction

The tolerances of many functional groups, e.g. aryl-chloride, aryl-bromide, alkene, alkynyl, ester, ether, oxhydryl, carboxylic acid, cyano group, nitrine, carbonyl, acyl, thioether and some heterocycles, were studied with unprecedentedly high chemoselectivity.

Regioselective synthesis of novel 4,5-diaryl functionalized 3,4-dihydropyrimidine-2(1H)-thiones via a non-Biginelli-type approach and evaluation of their in vitro anticancer activity

An easy and novel approach to synthesize 4,5-diaryl functionalized 3,4-dihydropyrimidine-2(1H)-thiones via addition of aryllithiums to 5-aryl substituted pyrimidine-2(1H)-thiones, which could be regarded as a method complementary to the most widely used Biginelli-type synthesis, is described. In the reaction of aryllithiums with N-(Me)Bn substituted pyrimidine-2(1H)-thiones a high degree of regioselectivity of addition, leading to 4-aryl adducts, was achieved. Selected compounds tested for their in vitro anticancer activity against four human cancer cell lines showed the greatest activity against breast cancer (MCF7). 1-Benzyl-4-(3-hydroxyphenyl)-5-phenyl substituted 3,4-dihydropyrimidine-2(1H)-thione (10g) exhibiting 10-fold more potent activity than the best known monastrol (MON) stands as a promising candidate for further scaffold and asymmetric synthesis.

Fe3O4–CNTs nanocomposites: a novel and excellent catalyst in the synthesis of diarylpyrimidinones using grindstone chemistry

The Fe₃O₄–CNTs in conjunction with grindstone chemistry have been used in this report to synthesize 5-unsubstituted pyrimidinones.

Recent progress in asymmetric Biginelli reaction

The Biginelli reaction, which involves the interaction of ethyl acetoacetate, urea, and an appropriate aryl aldehyde, was first discovered by Pietro Biginelli about 120 years ago. The Biginelli products (3,4-dihydropyrimidin-2(1H)-ones) are interesting materials due to their significant pharmacological and structural profiles. In the last decades, the asymmetric synthesis as a powerful tool has an effective impact on the Biginelli products and has increased their potencies and applications as drugs. Having the importance of this subject in mind, in this review we wish to present the recent rapid progress of asymmetric Biginelli reaction.

The combined role of catalysis and solvent effects on the Biginelli reaction: improving efficiency and sustainability

The traditional Biginelli reaction is a three-component condensation between urea, benzaldehyde and an acetoacetate ester to give a dihydropyrimidinone. An investigation into catalytic and solvent effects has returned the conclusion that the diketo-enol tautomerisation equilibrium of the dicarbonyl reactant dictates the yield of the reaction. Whereas the solvent is responsible for the tautomerisation equilibrium position, the catalyst only serves to eliminate kinetic control from the reaction. Generally, to preserve reaction efficiency and improve sustainability, bio-derivable p-cymene was found to be a useful solvent. The metal-enolate intermediate that results from the application of a Lewis acidic catalyst often cited as promoting the reaction appears to hinder the reaction. In this instance, a Brønsted acidic solvent can be used to return greater reactivity to the dicarbonyl reagent.

A Simple and Efficient One-pot Synthesis of 4-alkyl-3,4-dihydropyrimidin-2(1H)-ones

4-Alkyl-3,4-dihydropyrimidin-2(1 H)-ones possess a number of important properties in comparison with their 4-aryl analogues. We show that these compounds can be synthesised by a simple one-pot reaction of urea or thiourea, different aliphatic aldehydes (from acetaldehyde to valeraldehyde) and various dicarbonyl compounds (ethyl acetoac-etate, pentane-2,4-dione, N-(4-chlorophenyl)-3-oxobutanamide, acetoacetaldehyde dimethylacetal) in refluxing DMF or HOAc without use of any catalyst. The methylation of 4-alkyl-5-C(O)R-3,4-dihydropyrimidin-2(1 H)-ones leads to 1-methyl derivatives.

A Green and Efficient Method for the Preparation of 3,4-Dihydropyrimidin-2(1H)-ones Using Quaternary Ammonium-Treated Clay in Water

A variety of 3,4-dihydropyrimidin-2(1H)-ones derivatives were synthesized via three-component Biginelli reaction. The quaternary ammonium-treated clay-catalyzed process proved to be simple, efficient, and environmentally friendly.

Monolayer-Protected Silver Nanoparticles: An Efficient and Versatile Reagent for the Synthesis of 3,4-Dihydropyrimidine-2-(1H)-Ones (Thiones)

Silver nanoparticles has been prepared and shown to efficiently catalyse the one-pot, three-component reaction of an aromatic aldehyde, urea or thiourea and a 1,3-diketone at reflux, to afford the corresponding 3,4-dihydropyrimidine-2-(1H)-ones in high yield.