Nano-sulfated zirconia as an efficient, recyclable and environmentally benign catalyst for one-pot three component synthesis of amidoalkyl naphthols

New magnetic nanocomposite Fe3O4@Saponin/Cu(II) as an effective recyclable catalyst for the synthesis of aminoalkylnaphthols via Betti reaction

In this research, a new magnetic nanocomposite Fe₃O₄@Saponin/Cu(II) based on quillaja saponin was prepared and the catalyst structure was characterized thoroughly using FT-IR, EDS, TGA, XRD, VSM, HR-TEM, SEM, ICP, BET analyzes. The catalyst prepared in the three-component synthesis of several Betti bases, 1-(α-aminoalkyl)naphthols, under environmentally friendly conditions was used. The advantage of this reaction is the high efficiency of the products and the short reaction time. Furthermore, Fe₃O₄@Saponin/Cu(II) nano-catalyst is recoverable magnetically and is reusable for other processes with no reduction in its activity.

One-pot three-component synthesis of 1-amidoalkyl naphthols and polyhydroquinolines using a deep eutectic solvent: a green method and mechanistic insight

The multicomponent synthesis of 1-amidoalkyl naphthols and polyhydroquinolines has been developed as an atom-economic procedure catalyzed by a deep eutectic solvent ([CholineCl][ZnCl₂]₃).

Adipic Acid as a Biodegradable Solid Acid Catalyst for One-Pot, Three Component Synthesis of 1-Amidoalkyl-2-naphthols

Background:

1-Amidoalkyl-2-naphthols are an attractive group of organic compounds that can be converted to oxazine heterocycles and aminoalkyl naphthols. The derivatives of 1- amidoalkyl-2-naphthols have significant biological activities and act as drug candidates.

Methods:

1-Amidoalkyl-2-naphthols were synthesized via the three-component condensation reaction of 2-naphthol, acetamide/benzamide and various aldehydes in the presence of 10 mol% of adipic acid as an organocatalyst under solvent-free conditions at 120°C.

Results:

A simple, efficient, and operative method for the synthesis of 1-amidoalkyl-2-naphtholes in the presence of adipic acid as the biodegradable catalyst is introduced. Easy operation, acceptable reaction times, eco-friendly, availability of starting materials, simple separation of products, and high yields of products are the significant results of this method.

Conclusion:

In this study, 1-amidoalkyl-2-naphthols were synthesized using commercially available reactants in excellent yields and relatively shorter times. In this process, microwave or ultrasonic waves were not used to provide energy for the reaction.

Mannich base-connected syntheses mediated by ortho-quinone methides

This article provides an overview about specifically modified Mannich reactions where the process involves an ortho-quinone methide (o-QM) intermediate. The reactions are classified on the basis of the o-QM source followed by the reactant, e.g., the dienophile partner in cycloaddition reactions (C=C or C=N dienophiles) or by the formation of multicomponent Mannich adducts. Due to the important pharmacological activities of these reactive o-QM intermediates, special attention is paid to the biological activity of these compounds.

Effect of Sulfation on Zirconia-Pillared Montmorillonite to the Catalytic Activity in Microwave-Assisted Citronellal Conversion

Preparation of sulfated zirconia-pillared montmorillonite was carried out in two steps; zirconia pillarization and sulfation to zirconia-pillared montmorillonite. The prepared materials were characterized by using X-ray diffraction (XRD), measurement of the specific surface area, total pore volume and pore size distribution by the N2adsorption method, scanning electron microscopy-energy dispersive X-ray (SEM-EDX), and surface acidity determination by using pyridine adsorption-FTIR analysis. The activity of the materials as catalysts was evaluated for a microwave-assisted conversion of citronellal. The results showed that the prepared materials had a physicochemical character that promoted high catalytic activity to convert citronellal. From varied Zr content and study of the effect of sulfation on the activity, it was found that Zr content and sulfation increase the surface acidity of the material as shown by the higher total conversion and tendency to produce menthol as a product of the tandem cyclization-hydrogenation mechanism.