Current Organic Chemistry - Volume 25, Issue 23, 2021

Simultaneous electrocatalytic conversion of biomass into high-value products and electrolysis of water for hydrogen are promising strategies to relieve the fossil energy crisis. Herein, we overview the recent advances and perspectives in the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) and water reduction to synchronously produce value-added 2,5-furandicarboxylic acid (FDCA) and hydrogen fuel. Two strategies of bifunctional electrocatalysts and redox mediators are discussed. Oxidation of HME to FDCA was found to be more thermodynamically and kinetically favorable than the Oxygen Evolution Reaction (OER). Moreover, the opportunities and challenges brought by them are presented.

Triazoles are five-membered aromatic heterocyclics, which exhibit two isosteric forms (1,2,3-triazoles and 1,2,4-triazoles), as well as multiple applications in medicinal, agricultural, supramolecular, and materials sciences. Famous examples of triazoles include drugs, such as fluconazole, ribavirin, cefatrizine, and tazobactam, as well as herbicides, such as cafenstrole and metosulam. This review aims to present the recent major examples of the application of microwave-assisted organic synthesis (MAOS) to the syntheses and endfunctionalizations of 1,4- and 1,5-disubstituted 1,2,3-triazoles, 1,2,4-triazoles, 3-amino-1,2,4- triazoles, 1,2,4-triazol-3-one, and 1,2,4-triazol-3-thiol derivatives. Notably, the previous reviews on triazole syntheses have not exclusively elucidated the relevance of MAOS techniques in the obtention and derivatization of these compounds.

1,4-benzoxazine compounds are an important class of heterocyclic compounds. Ever since 1,4-benzoxazine was discovered in 1959, it has attracted chemists due to its unique physiological activities, and their synthesis and application have been studied. However, the traditional synthesis methods of 1,4-benzoxazines have some drawbacks, such as complicated steps, harsh reaction conditions and low yield. Therefore, it is still a significant direction to develop new and efficient synthesis methods. In this paper, the synthesis methods and reaction mechanisms of these compounds are reviewed, and the application prospect of 1,4- benzoxazine and its derivatives as a dominant active structure in the future is discussed.

Pyrido[2,3-d]pyrimidine is an N-fused heterocyclic compound formed by the ortho fusion of pyridine and pyrimidine ring. Pyrido[2,3-d]pyrimidines hold a prominent position in medicinal chemistry owing to their wide spectrum of biological activities like antiviral, antihistaminic, antibacterial, diuretic, anti-inflammatory, analgesic, anticonvulsive, antipyretic, etc. The extraordinary features of pyrido[2,3-d]pyrimidines make their synthesis a perpetual field of research. Moreover, the construction of elaborate biologically relevant moieties via a multicomponent approach has become a promising area of research, owing to the burgeoning ‘green chemistry drive’. Advances in the exploitation of proficient synthetic routes involving a multicomponent approach for the assembly of this scaffold are reported in this review.

One of the principal causes of different disorders is an uncontrolled inflammatory response. Alkaloids, flavonoids, polyphenolic, proanthocyanidin, terpenoid, and steroid compounds are the main reasons for the anti-inflammatory activities of medicinal herbs and plants. The current manuscript introduces a series of potential anti-inflammatory plants, particularly those which are routines in Iranian and Chinese traditional herbal medicine, and simplifies the function and mechanisms of natural constituents for the prevention and treatment of inflammatory disorders. PubMed, Science Direct, Google Scholar, Wiley Online Library, Springer, Taylor, Francis, etc., have been used to search for collecting of scientific publications for a full evaluation of current documentation in the literature showing the importance of medicinal plants with anti-inflammatory characteristics and natural medicines. The most notable medicinal plants with anti-inflammatory activities are Baccharis dracunculifolia, Aconitum bulleyanum, Crateya adansonii, Alliums spp., Centella asiatica, Flos lonicerae, Corydalis dubia, Syringae folium, Coptis chinensis, Casearia decandra, Nigella sativa, Cannabis sativa, Tamarindus indica L., Glycyrrhiza glabra, Panax ginseng, Panax notoginseng, Pistacia vera, Smilax china, Scutellaria baicalensis, Rosemarinus officinalis, Moringa olifera, Pulsatilla radix, Pistacia atlantica, Rullia tuberose, Canarium album, Dodonaea polyandra, Forsythia suspense, Polygala tenuifolia, Radiz Isatidis, Hypericum sampsonii, Geranium koreanum, Typha capensis, Isatidis folium, Ginkgo biloba, Houttuynia cordata, snow lotus, etc. Herbal medicine mainly uses numerous parts of plants or combinations of them to prevent and remedy diseases and promote health. More investigations and clinical experiments are needed to provide more information on the importance of medicinal plants as well as their roles in the treatment and prevention of inflammatory diseases.

Single-crystal X-ray diffraction analysis, nuclear magnetic resonance (NMR), and other characterization methods are used to characterize the complexes formed by cyclopentano- cucurbit[6]uril (abbreviated as CyP6Q[6]) as a host interacting with p-aminobenzenesulfonamide (G1), 4,4'-diaminobiphenyl (G2), and (E)-4,4'-diamino-1,2-diphenylethene (G3) as guests, respectively. The experimental results show that these three aromatic amine molecules have the same interaction mode with CyP6Q[6], interacting with its negatively electric potential portals. The supramolecular interactions include non-covalent interactions of hydrogen bonding and ion-dipole between host and guest molecules. CdCl2 acts as a structureinducing agent to form self-assemblies of multi-dimensional and multi-level supramolecular frameworks that may have potential applications in various functional materials.