The applications of nitroalkenes in the synthesis of three-to five-membered O, N and S-heterocycles, including natural products are investigated in this review. These heterocyclic compounds were synthesized from nitroalkenes with a variety of substituents at the a and b-positions and those that were part of common and medium rings via a wide variety of reactions such as Michael addition reactions, epoxidation, [3 + 2] cycloaddition and many cascade/domino/tandem reactions. In addition, the potential of nitroalkenes to take part in multi-component and cascade reactions, particularly, in diastereo-and enantioselective versions is reviewed. The high reactivity of nitroalkenes and their potential to coordinate with the metal catalysts as well as organocatalysts signify them as efficient precursors in synthetic organic chemistry. Also, the flexibility of the nitro group in functional group manipulations has expanded the scope of the nitro group, in general, and nitroalkenes, in particular, in organic synthesis.

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A facile and efficient procedure for the synthesis of substituted thiazole-2(3H)-thiones and thiazolidine-2-thiones by the reaction of primary amines, carbon disulfide, and nitroepoxides is described. By using secondary amines in this protocol, the corresponding dithiocarbamate-substituted phenyl-2-propanones were prepared in excellent yields. In addition, substituted thiazoles and 1-(alkylthio)-1-phenylpropan-2-ones were prepared in reactions of S-alkyl dithiocarbamates and nitroepoxides.

A novel magnetically recoverable solid acid catalyst was synthesized by immobilization of sulfonic acid groups on triazine dendrimer-modified magnetic nanoparticles. The structure and composition of the synthesized catalyst were characterized by thermogravimetric analysis (TGA), elemental analysis, Fourier transform infrared spectroscopy (FT-IR), energy-dispersive X-ray (EDX) spectroscopy, elemental mapping, acid–base titration, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The catalytic performance of the catalyst was evaluated for the conversion of carbohydrates to 5-hydroxymethylfurfural (5-HMF) in various deep eutectic mixtures as neoteric green and environmentally benign reaction media. Among the 13 deep eutectic mixtures investigated, the mixture comprising equal moles of sucrose and fructose yielded the highest 5-HMF yield. No additional reaction solvent was necessary since the sucrose/fructose (1:1, mol/mol) system acted as a combined solvent and substrate for 5-HMF production. Thus, this catalyst system would open up a novel opportunity for the efficient production of 5-HMF under solvent-free conditions. Moreover, the catalyst could be simply separated from the reaction mixture by using a magnetic field and recycled up to five times without incredible loss in its activity.

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