Nouvelle voie de synthèse des 2-trifluorométhylarylimidazoles sur montmorillonite K10 en ‘milieu sec’ sous micro-onde

A serendipitous one-step conversion of 3H-1,2-dithiole-3-thione to (E)-3-[1-(alkylthio)alkylidene]-3H-1,2-dithiole: an experimental and theoretical study

In the course of our studies on 3H-1,2-dithiole-3-thione synthesis, a serendipitous reactivity with α-haloketones, in the presence of excess of potassium iodide, has been observed. Instead of the expected reaction of the nucleophile in a remote point of the molecule, we have obtained a product resulted from the electrophile character of the thiocarbonyl moiety on the 3-position of the 1,2-dithiole. In order to obtain an efficient protocol in terms of energy efficiency, this methodology was studied under conventional and microwave heating with similar or better results in the latter conditions. Simplicity and great efficiency in this one-step transformation are some of the advantages of this reaction. Moreover, the results can be explained according to the Pearson's hard and soft acid base theory.

Microwave-assisted and efficient solvent-free knoevenagel condensation. A sustainable protocol using porous calcium hydroxyapatite as catalyst

A sustainable Knoevenagel condensation of a series of aldehydes with malononitrile and ethyl cyanoacetate is described. The process is based on the combination of microwave activation and hydroxyapatite catalysis under solvent-free conditions. Products are obtained in and high yields after short reaction times. The effects of the specific surface of porous calcium hydroxyapatite and microwave activation are discussed.

Parallel and automated library synthesis of 2-long alkyl chain benzoazoles and azole[4,5-b]pyridines under microwave irradiation

A versatile route to 40-membered library of 2-long alkyl chain substituted benzoazoles (1 and 2) and azole[4,5-b]pyridines (3 and 4) via microwave-assisted combinatorial synthesis was developed. The reactions were carried out in both monomode and multimode microwave oven. With the latter, all reactions were performed in high-throughput experimental settings consisting of an 8 x 5 combinatorial library designed to synthesize 40 compounds. Each step, from the addition of reagents to the recovery of final products, was automated. The microwave-assisted N-long chain alkylation reactions of 2-alkyl-1H-benzimidazole (1) and 2-alkyl-1H-benzimidazole[4,5-b] pyridines (3) were also studied.

Montmorillonite K10 clay: an efficient catalyst for the one-pot stereoselective synthesis of beta-acetamido ketones

An efficient one-pot three-component coupling process for the synthesis of beta-acetamido ketones catalyzed by montmorillonite K10 clay is described. The reaction is highly stereoselective and the catalyst can be recycled.