Sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) with a pore size of 6 nm catalyzed three component coupling of aromatic aldehydes, urea and ethyl acetoacetate to afford the corresponding dihydropyrimidinones under solvent free condition. This new protocol for Biginelli reaction has important advantages such as green synthesis, short reaction time, easy isolation and high yields of ...

This article describe the applicability of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2].2Cl) as a green, versatile and Brönsted acidic ionic catalyst in the promotion of the synthesis of phthalazine derivatives via one-pot three component reaction between aromatic aldehydes, 1,3-diketone derivatives and phthalhydrazide under solvent-free reaction cond...

abstract the effect of weight and force is one of the most important factors to organize and perform reaction time (rt) tasks. the elderly are involved in this variable when they gain weight. the present study was designed to examine the effect of limb weight gain on premotor and motor components of simple and discriminative reaction time in young and elderly men. subjects (16 young and 16 elde...

We present herein a new and efficient four-component synthesis of isoxazol-5(2H)-ones involving ring closing/Knoevenagel condensation/Michael addition sequential reactions.

A facile and efficient one-pot, multicomponent synthesis of 4H-chromenes is reported, through the reaction of arylglyoxalmonohydrates with 1,3-diketones and malononitrile in eTEMPthanol in the presence of L-proline as a catalyst.

Nano TiO2 supported on SiO2 (Nano TiO2@SiO2) as a solid Lewis acid, was described to be an effective and reusable catalyst for one-pot three-component reaction of benzil, aryl aldehydes and ammonium acetate for the synthesis 2-aryl-4,5-diphenyl-1H-imdazoles synthesis. To explore the high efficacy of the catalytic system the four-component cyclization of benzil, aryl aldehydes, ammonium acetate ...

A simple, efficient, and high yielding one-pot protocol has been developed for the synthesis of 4H-benzo[b]pyrans scaffolds installing a three-component tandem Knoevenagel-cyclocondensation reaction of an aldehyde, malononitrile and dimedone using guanidinium chloride as polyfunctional organocatalyst under solvent-free conditions in high to excellent yields. Various aromatic aldehydes were util...

Ionic liquid 1,3-disulfonic acid imidazolium trifluoroacetate ([Dsim][TFA]) has been exploited as a highly efficient catalyst for the one-pot pseudo five-component reaction of phenylhydrazine (2 eq.) with ethyl acetoacetate (2 eq.) and arylaldehydes (1 eq.) in ethanol (reflux conditions). In this reaction, 4,4′‐(arylmethylene)‐bis(3‐methyl‐1‐phenyl‐1H‐ pyrazol‐5‐ol)s have been obtained in high ...

An efficient and simple one-pot approach for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives using antimony trichloride (SbCl3) as a mild catalyst by means of three-component Biginelli reaction between β-keto esters, aldehyde derivatives and urea/thiourea under thermal and solvent-free conditions with excellent yields and short reaction times is reported. This m...

Sulfonic acid functionalized nanoporous silica (SBA-Pr-SO3H) with a pore size of 6 nm catalyzed three component coupling of aromatic aldehydes, urea and ethyl acetoacetate to afford the corresponding dihydropyrimidinones under solvent free condition. This new protocol for Biginelli reaction has important advantages such as green synthesis, short reaction time, easy isolation and high yields of ...