Four-component Procedure Research Articles

A facile and green synthesis of poly-hydroquinoline analogues in aqueous medium by CeO2-FAp@MWCNT as recyclable catalyst

The fabrication of composite materials with different loading of titanium dioxide on hydroxyapatite (CeO2-FAp@MWCNT) has been described in detail. The morphological and structural characteristics of the samples were assessed by several techniques such as FT-IR, SEM, TEM, BET, and p-XRD analysis. A four-component procedure was used to create novel poly-hydroquinoline analogues, and the catalytic efficiency of these composite materials was studied. Cyclohexanedione, ethyl acetoacetate/benzyl 3-oxobutanoate, NH4OAc, and a variety of substituted aldehydes were used in one-pot reaction that was carried out in an aqueous medium under heating condition. The approach produced high product yields (93–98 %) quickly (within 15 min) at room temperature. In addition, we assessed the effectiveness of the separated catalyst, which exhibited stable catalytic activity for a maximum of seven runs. This environmentally friendly approach provides simple workup, quick reaction times, high yields, reusable catalysts, a gentle reaction environment, and purification without the need for column chromatography.

A One-Pot Four-Component Procedure for the Synthesis of Dispiro[tetrahydroquinoline-bis(2,2-dimethyl-1,3-dioxane-4,6-dione)] Derivatives

A One-Pot Four-Component Procedure for the Synthesis of Dispiro[tetrahydroquinoline-bis(2,2-dimethyl-1,3-dioxane-4,6-dione)] Derivatives

Asymmetric synthesis approach of enantiomerically pure spiro-indenoquinoxaline pyrrolidines and spiro-indenoquinoxaline pyrrolizidines

An efficient, one-pot, four-component procedure for the synthesis of a small library of novel chiral spiro-indenoquinoxaline pyrrolidines and chiral spiro-indenoquinoxaline pyrrolizidines with high regio-, diastereo- (up to 96 dr), and enantioselectivity (up to 99% ee), through a 1,3-dipolar cycloaddition reaction of azomethine ylides and an optically active cinnamoyl–crotonoyl oxazolidinone is described. This methodology was very simple and was utilized to construct complex products from simple starting materials. The process was carried out in aqueous ethanol as an eco-friendly solvent and in the absence of any Lewis acids catalysts. The oxazolidinone chiral auxiliary was removed through a non-destructive protocol. The reaction mechanism is discussed on the basis of the assignment of the absolute configuration of the cycloadducts and using quantum mechanical calculations. The regio- and stereoselectivity were described on the basis of transition states’ stabilities and global and local reactivity indices of the reactants. The results of the theoretical calculations are in agreement with the experimental outcomes.

ChemInform Abstract: One‐Pot, Sequential Four‐Component Synthesis of Thiazepine Derivatives.

A one-pot, sequential, four-component procedure for the synthesis of thiazepines by the reaction of primary amines, 1,3-dicarbonyl compounds, aryl isothiocyanates, and chloroacetyl chloride at room temperature is described. Advantages of this protocol include ease of handling, regioselectivity, the absence of a metal catalyst, and moderate yields.

One-Pot, Sequential Four-Component Synthesis of Thiazepine Derivatives

A one-pot, sequential, four-component procedure for the synthesis of thiazepines by the reaction of primary amines, 1,3-dicarbonyl compounds, aryl isothiocyanates, and chloroacetyl chloride at room temperature is described. Advantages of this protocol include ease of handling, regioselectivity, the absence of a metal catalyst, and moderate yields.

A facile three- and four-component procedure toward the synthesis of functionalized pyrano- and benzo[f]quinoxaline derivatives

A two-step procedure has been used to synthesize quinoxaline derivatives in the presence of a catalytic amount of triethylamine. Products can be separated from the reaction media by simple filtration. When EtOH was used as a solvent, the reaction proceeded via a three-component pathway, but in the presence of MeOH (as a solvent or in a 1-equivalent) the reaction proceeded via a four-component pathway.

A novel, fast and efficient one-pot four-component procedure for preparation of some alkyl spiro[indeno[1,2-b]quinoxaline-11,3′-pyrrolizine]-2′-carboxylates

In this study we report a novel one-pot reaction which stereoselectively affords alkyl spiro[indeno[1,2-b]quinoxaline-11,3′- pyrrolizine]-2′-carboxylates via the four-component condensation of ninhydrin, phenylenediamines, proline, and acrylic acid derivatives. The reactions were run in ethanol and completed at less than 25 min and the products were obtained in very good yields. The stereochemistry of the products was deduced on the basis of the 1H NOESY and comparison with the related systems.

Synthesis of Piperidinones via a Multicomponent Condensation

A four-component procedure for the synthesis of polyfunctionalized piperidin-4-ones has been developed. In this reaction, the im­ine is premixed with TiCl4 followed by the addition of diketene and methanol and finally the aldehyde component is added. Reasonable scope in terms of derived substitution patterns was studied. The resulting diastereomeric mixtures of piperidin-4-ones, obtained in good to excellent yields, were successfully converted into single diastereomers under basic conditions (K2CO3/DMF). The ste­reochemistry was assigned by single crystal X-ray structure analysis of a selected piperidinone.

A clinical decision-making model for child psychiatric intervention selection.

This paper describes a four-component procedure of clinical decision-making, developed by a group of senior child clinicians in an urban child mental health center. The major goal of the paper is to give readers a basic understanding of the theory underlying the formulation of our disposition-oriented clinical decision-making system, that can be eventually translated into questionnaire format, and made useful and usable in general clinical application. The four-component procedure is described in a step-wise fashion and then linked to clinical dispositional options to be chosen from the clinical services available in a clinic. A child mental health data system will ultimately be developed.