Efficient synthesis of β-enaminones and β-enaminoesters catalyzed by gold (I)/silver (I) under solvent-free conditions

Clean and Efficient Green Protocol of N,N'-Bis(2-(arylazo)-2-(aroyl)vinyl)ethane-1,2-diamines in Aqueous Medium without Catalyst: Synthesis and Photophysical Characterization

An interesting platform for the construction of novel N,N'-bis(2-(arylazo)-2-(aroyl)vinyl)ethane-1,2-diamines is reported in this work. These bis-arylazo compounds were assembled based on the reaction of ethylenediamine with various 2-arylhydrazono-3-oxopropanals in aqueous conditions under both conventional stirring and microwave conditions at ambient temperature. The factors affecting the optimization conditions were intensively practiced. The structures of the new products were established from their spectroscopic analyses and X-ray single crystals. The photophysical behavior of the bis-arylazo derivatives was examined. The UV-vis spectra showed maximum absorption band in the range of 348-383 nm with molar extinction coefficients ranging from 0.89 × 104 to 4.02 × 104 M-1 cm-1. The highest molar absorptivity coefficient (∼45 × 103 M-1 cm-1) was observed in CHCl3 solvent. The fluorescence properties showed that some compounds were interesting fluorophore materials with high Stokes shifts. The photoluminescence study of some compounds was promising, with maximal emission peaks ranging between 417-436 nm.

Dinuclear cobalt complexes supported by biphenol and binaphthol-derived bis(salicylaldimine) ligands: synthesis, characterization and catalytic application in β-enaminone synthesis from 1,3-dicarbonyl compounds and aliphatic amines

Biaryl scaffolding ligands form dicobalt clusters, which serve as efficient catalysts in enaminone synthesis under ambient conditions.

Diastereoselective Synthesis of Symmetrical and Unsymmetrical Tetrahydropyridines Catalyzed by Bi(III) Immobilized on Triazine Dendrimer Stabilized Magnetic Nanoparticles

Unsymmetrical 1,2,5,6-tetrahydropyridine-3-carboxylates were obtained for the first time from a five-component Fe₃O₄@TDSN-Bi(III)-catalyzed reaction of aryl aldehydes, aryl amines, and ethyl acetoacetate. This magnetically separable catalyst enabled the selective incorporation of two different aryl amines or two different aryl aldehydes into the product, and provided excellent yields, short reaction times, mild reaction conditions, satisfactory catalyst recyclability, and low catalyst loading.