Microwave promoted one-pot synthesis of 2-aryl substituted 1,3,4-oxadiazoles and 1,2,4-oxadiazole derivatives using Al3+-K10 clay as a heterogeneous catalyst

Electrochemical synthesis of 1,2,4-oxadiazoles from amidoximes through dehydrogenative cyclization

A convenient and efficient method for the generation of the iminoxy radical through anodic oxidation was developed for the synthesis of 3,5-disubstituted 1,2,4-oxadiazoles from N-benzyl amidoximes. The transformation proceeds through 1.5-Hydrogen Atom Transfer (1,5-HAT) and intramolecular cyclization. The process features simple operation, mild conditions, broad substrate scope and high functional group compatibility, and provides a facile and practical way for the preparation of 1,2,4-oxadiazoles.

Montmorillonite clay-based heterogenous catalyst for the synthesis of nitrogen heterocycle organic moieties: a review

The use of montmorillonite clay as solid catalyst has grabbed much attention in the liquid phase reactions for organic synthesis. In recent years, there has been a lot of interest in organic synthesis using montmorillonite-based composites, especially in the synthesis of heterogeneous nanoparticles. Due to the robust and green nature of montmorillonite-based nanocatalysts, it has been widely used in N-heterocyclic reactions. In this review, we have concentrated on the reports pertaining the use of montmorillonite-based nanocatalyst in the synthesis of N-heterocycles, a category of organic compounds with excellent biological properties. This manuscript is arranged by the types of N-containing heterocycles synthesized using montmorillonite-based composite as catalysts including polycyclic spirooxindoles, heterocyclic propargylamine, indole-based heterocycles, quinoline and its derivatives, six-membered N-heterocyclic-based compounds and five-membered N-heterocyclic-based compounds. Special attention was given to the structural stability under experimental parameters of the montmorillonite-based composite with the incidence of metal leaching and reusability. Finally, along with recent developments, new findings in heterogeneous montmorillonite (Mt)-based catalysis have also been addressed.

Carbodiimide-based synthesis of N-heterocycles: moving from two classical reactive sites to chemical bond breaking/forming reaction

Carbodiimides are a unique class of heterocumulene compounds that display distinctive chemical properties. The rich chemistry of carbodiimides has drawn increasing attention from chemists in recent years and has made them exceedingly useful compounds in modern organic chemistry, especially in the synthesis of N-heterocycles. This review has outlined the extensive application of carbodiimides in the synthesis of N-heterocycles from the 1980s to today. A wide range of reactions for the synthesis of various types of N-heterocyclic systems (three-, four-, five-, six-, seven-, larger-membered and fused heterocycles) have been developed on the basis of carbodiimides and their derivatives.

The crystal structure of 2-(4-fluorophenyl)-1,3,4-oxadiazole, C8H5FN2O

C8H5N2O, monoclinic, P21 (no. 4) a = 7.892(8) Å, b = 6.088(6) Å, c = 15.701(16) Å, β = 90.08(3)°, V = 754.4(13) Å3, Z = 4, Rgt(F) = 0.0423, wRref(F2) = 0.1032, T = 273 K.

Synthesis and antioxidant activity of 1,3,4-oxadiazoles and their diacylhydrazine precursors derived from phenolic acids

Eight 1,3,4-oxadiazoles and eight of their diacylhydrazine precursors were synthesized and examined for their antioxidative potential using different tests.

A facile approach to synthesize 3,5-disubstituted-1,2,4-oxadiazoles via copper-catalyzed-cascade annulation of amidines and methylarenes

A tandem Cu-catalyzed oxidation–amination–cyclization reaction for synthesizing various 3,5-disubstituted-1,2,4-oxadiazoles from easily available amidines and methylarenes or methylhetarenes is reported.

K10 montmorillonite clays as environmentally benign catalysts for organic reactions

This perspective summarizes the catalytic activity of K10 montmorillonite as a multifunctional catalyst for organic reactions.