Guo-Feng Chen

A facile synthesis of α, α'-bis(substituted benzylidene) cycloalkanones catalyzed by KF/Al2O3 under ultrasound irradiation

Abstract The condensation of the cyclopentanone or cyclohexanone with aromatic aldehydes catalyzed by KF/Al2O3 in MeOH under ultrasound irradiation, result the corresponding 2,5-bis(substituted benzylidene) cyclopentanones or 2,6-bis(substituted benzylidene) cyclohexanones in good yields.

The Michael reaction catalyzed by KF/basic alumina under ultrasound irradiation

The Michael reaction of chalcones as acceptors with various active methylene compounds such as diethyl malonate, nitromethane, cyclohexanone, ethyl acetoacetate and acetylacetone as donors catalyzed by KF/basic alumina results in adducts in high yield within a shorter time under ultrasound irradiation.

An efficient synthesis of 2-substituted benzothiazoles in the presence of FeCl3/Montmorillonite K-10 under ultrasound irradiation.

2-Substituted benzothiazoles have been synthesized via one-pot reaction from aromatic aldehydes and o-aminothiophenol in the presence of FeCl(3)/Montmorillonite K-10 in absolute methanol at 25-30°C under ultrasound irradiation. The remarkable advantages are an inexpensive and easily available reagent, a simple procedure, mild conditions, short reaction times and moderate to good yields.

Efficient synthesis of 2,3-disubstituted-2,3-dihydroquinazolin-4(1H)-ones catalyzed by dodecylbenzenesulfonic acid in aqueous media under ultrasound irradiation

Synthesis of 2,3-disubstituted-2,3-dihydroquinazolin-4(1H)-one derivatives catalyzed by dodecylbenzenesulfonic acid was carried out in 80-92% yields at 40-42 °C within 1-2 h in aqueous media via one-pot three-component condensation of isatoic anhydride, aromatic aldehyde and amine under ultrasound irradiation. Convenient work-up procedures, mild reaction conditions, avoiding the use of organic solvents, and friendly to environment are the salient features of this protocol.

Michael Addition Catalyzed by Potassium Hydroxide Under Ultrasound

Abstract Michael addition of chalcone with active methylene compound such as diethyl malonate, nitromethane and ethyl acetoacetate catalyzed by potassium hydroxide in anhydrous ethanol results Michael adducts in 75–98% yield under ultrasound irradiation in 25–90 min.

Ultrasound promoted synthesis of 2-aroyl-1,3,5-triaryl-4-carbethoxy-4-cyanocyclohexanols.

Synthesis of 2-aroyl-1,3,5-triaryl-4-carbethoxy-4-cyanocyclohexanols from chalcones with ethyl cyanoacetate is carried out in excellent yields with KF/basic alumina as catalyst under ultrasound irradiation.

Ultrasound promoted one-pot synthesis of 3-aza-6,10-diaryl-2-oxa-spiro[4.5]decane-1,4,8-trione

One-pot synthesis of 3-aza-6,10-diaryl-2-oxa-spiro[4.5]decane-1,4,8-trione from 1,5-diaryl-1,4-pentadien-3-one can be carried out in good yields at 50 degrees C under ultrasound irradiation. This method provided several advantages such as simple work-up procedure, shorter reaction time and higher yield.

Synthesis of Arylmethylenemalononitriles Catalyzed by KF–Al2O3 under Ultrasound

Knoevenagel condensation of malononitrile with aromatic aldehydes catalyzed by KF–Al2O3 under ultrasound irradiation in anhydrous ethanol results in the formation of arylmethylenemalononitriles in 73–97% yields within 15–60 min.

Eco-Friendly Synthesis of 2-Substituted Benzimidazoles Using Air as the Oxidant

A simple, environmentally friendly procedure for the synthesis of 2-substituted benzimidazoles by the one-pot condensation of o-phenylenediamines with aromatic aldehydes using continuous bubbling of air in absolute ethanol at room temperature is described. The simplicity of the system, mild conditions, involvement of a non-toxic and practically inexhaustible oxidant, easy and quick isolation of the products, and moderate to good yields are the main advantages of this procedure.

A novel sodium iodide and ammonium molybdate co-catalytic system for the efficient synthesis of 2-benzimidazoles using hydrogen peroxide under ultrasound irradiation.

The reaction of aldehydes and o-phenylenediamine for the preparation of 2-benzimidazoles has been studied using hydrogen peroxide as an oxidant under ultrasound irradiation at room temperature in this paper. The combination of substoichiometric sodium iodide and ammonium molybdate as co-catalysts, together with using small amounts of hydrogen peroxide, makes this transformation very efficient and attractive under ultrasound. Thus, a mild, green and efficient method is established to carry out this reaction in high yield.