Microwave: A Green Contrivance for the Synthesis of N-Heterocyclic Compounds

Abstract

Microwave Mediated Organic Synthesis (MMOS) is typical on the proficient heat shift carried out by dielectric heating, which in turn, is primarily dependent on the capability of the reagent or solvent to take up microwave energy. The employment of microwave energy has witnessed a fast expansion in the past two decades, with novel and pioneering applications in peptide and organic synthesis, material sciences, polymer chemistry, biochemical processes and nanotechnology. This review summarizes current MW- mediated catalytic reactions in use for the synthesis of a diversity of N-heterocycles by Multi-Component Reactions (MCRs) and a variety of miscellaneous reactions. Also, the review addresses some aspects of the use of nanoparticles for a diversity of applications in microwave chemistry.

Microwave-assisted synthesis of a series of 4,5-dihydro-1H-pyrazoles endowed with selective COX-1 inhibitory potency

“…MW-assisted synthesis is recognized as an advantageous and eco-friendly technique for the rapid and efficient preparation of heterocyclic compounds including nitrogen-containing heterocycles. [31][32][33] The employment of this technique in dedicated MW reactors provides efficient and controlled heating along with excellent parameter control and therefore MW heating has several advantages over conventional heating such as shortening reaction time and obtaining products with high purity and yield. [31][32][33][34][35] In this work, an efficient MW-assisted protocol was applied for the preparation of compounds 2a-h.…”

“…[31][32][33] The employment of this technique in dedicated MW reactors provides efficient and controlled heating along with excellent parameter control and therefore MW heating has several advantages over conventional heating such as shortening reaction time and obtaining products with high purity and yield. [31][32][33][34][35] In this work, an efficient MW-assisted protocol was applied for the preparation of compounds 2a-h. Compounds 2a, 2b, 2c, 2d and 2e were previously synthesized by our research group using a conventional method.…”

review on green multicomponent synthesis of heterocyclic compounds

“…Designing the high efficiency reactions that work at room temperature and use of alternative energy sources has become an attractive choice. A radical evolution in the field of synthetic organic chemistry is the practice of multicomponent reactions (MCRs), which involve more than three reactants in one-pot reaction [33,34]. In addition to avoidance of separation and purification of intermediates, MCRs are generally environment friendly, selective, atomefficient and time saving [35][36][37].…”

Sulfamic Acid as Versatile Green Catalyst Used For Synthetic Organic Chemistry: A Comprehensive Update

“…[8] This zwitterionic acid is also used as a heterogeneous catalyst that can be easily recovered for subsequent reuse by simple filtration. [9] Accordingly, SA is recognized as an efficient and economically feasible green catalyst in organic transformations, [10][11][12][13][14] including functional group protections and deprotections, [15] synthesis of isoamyl acetate, [16] polymeric ethers, [17] esterification, [18] acetylation of alcohols and phenols, [19] αamino nitrile formation, [20] tetrahydropyranylation of alcohols, [21] and transesterification of β-ketoesters. [22] Further, other important organic reactions such as Beckmann rearrangement, [23] inter-and intra-molecular imino Diels-Alder reactions, [24] and Pechmann [25] and Biginelli condensations, [26] were successfully realized by the employment of SA of particular importance, owing to its zwitterionic nature and ability to form soluble metal complexes, sulfamic acid is a highly ionized, non-volatile acid, which is safely and eco-friendly used while avoiding the precipitation of undesirable insoluble salts.…”