: Diphenyl ethers (DPEs) are mainly produced by microorganisms and plants. The chemical structure of DPEs is relatively simple, and all of these compounds have the structure of biphenyl ethers in their chemical structure, the difference being the difference in the substituents on the benzene ring. Several recent studies have shown antibacterial, antioxidant, antitumor, antitumor, antihemolytic, neuroprotective, and anti-Alzheimer effects. DPEs could be candidate compounds for the treatment of Alzheimer's disease, by inhibiting the aggregation of Aβ42. Many DPEs from natural products exhibit good biological activity and they play an important role in the control of microbial infections. Diphenyl ethers have a wide range of applications and research value in the fields of pesticides, pharmaceuticals, textiles, household products, and public health. In this paper, we review the research progress of diphenyl ethers isolated from marine and plant endophytic sources in recent years, including their biosynthesis, and lay the foundation for further utilization and development.

: It was previously reported that azo compounds are vigorous and chemically stable compounds and well-known chromophores. Having different chromophores, the azo dyes act as probing units for capturing the charged particles either by electron transfer or deprotonation mechanisms. The probing efficiency usually exhibits in the magnitude of variations in UV absorbance, NMR peaks and visually observed color changes. The sensing application is a prerequisite for numerous analytical techniques involved in pharmaceutical as well as pathological discipline. In the last two decades, numerous azo based sensors have been developed, which render low cost and effective sensing approaches towards ionic diagnosis through instantaneous eye beaming chromogenic change. This sensing approach is simple, cost-effective, and precise and provides reliable quantitative and qualitative statistics of an analyte present in a complex environment. Our present study culminates the recent progress on the synthesis of azo compounds and their chromogenic sensing application towards various reactive analytes through reviewing spectral variations and colorimetric observations. This review article assesses the potential of azo dyes in chromogenic sensing for different analytes. We believe this review will be of interest and important for researchers working on designing azo-based chromogenic sensors.

: This review described the preparation of 2-(piperazin-1-yl) quinoline derivatives from 2-haloquinolines and anilides, which underwent alkylation, arylation, acylation, and reductive amination to form the 2-piprazinoquinolines. 2-(Piperazin-1-yl) quinoline used as building blocks for the synthesis of polyfunctionalized heterocyclic compounds with pharmacological interest.

: In the field of Chemistry, it is essential to study molecules with biological activity on chronic degenerative diseases to design drugs that help to improve the health of people with diseases such as diabetes, arterial hypertension, rheumatoid arthritis, cancer, among others; and that in turn may have fewer side effects. Diabetes mellitus is a serious metabolic disorder that affects millions of people worldwide; due to the illness severe affectations, there is a great interest in improving pharmacological treatments (hypoglycemic drugs) used in this disease. Nowadays, it has been reported that metallodrugs and drug-cyclodextrin inclusion compounds have higher therapeutic activity than free drugs, with fewer side effects. In the present work, we compile, analyze, synthesize and discuss published information on the hypoglycemic drugs Metformin (C4H11N5), Chlorpropamide (C10H13ClN2O3S) and Glibenclamide (C23H28ClN3O5S) complexed with metal ions or included in cyclodextrins in aqueous solution. Nowadays, this type of complex should be widely studied for the treatment of type 2 diabetes mellitus. Physicochemical and thermodynamic properties, synthesis, mechanism of action, as well as analytical studies on the interaction of hypoglycemic agents with different complexing agents, are discussed.

: Natural products with oxa-bridged medium-sized carbocyclic ring structure units play an important role in nature. Therefore, developing novel and efficient methods is essential for synthesizing complex natural products containing oxygen-bridged rings. In this article, pro-gress toward the synthesis of oxygen-bridged seven and eight-membered rings is reviewed in terms of the strategies employed.

: Over the previous decades, thieno-quinoline derivatives have acquired great interest due to their synthetic and biological applications. These reports have been disclosed on Thienoquinoline synthesis such as thieno[3,4-b]quinoline; thieno[3,4-c]quinolone; thieno [3,2-g]quinoline; thieno[2,3-g] quinoline; spiro-thieno[2,3-g]quinoline; benzo[b]thiophen-iso- quinoline derivatives, and therefore in the existent review, we provided an inclusive update on the synthesis of thienoquinolines. Characterization of the preparation methods and reactivity is categorized based on their types of reactions as addition, alkylation, chlorination, acylation, oxidation, reduction, cyclization and cyclo-condensation. Hence, this study will help the researchers to obtain knowledge from the last literature research to conquer their resolve problems in designing new compounds and processes.

The extension of carbon chains, known as homologation, is one of the most fundamental operations of organic synthesis. One and two-carbon homologation reactions are of immense importance because they can be used for synthesizing members of a homologous series by iterative operations. Homologation reactions produce higher analogues of the same functional group, whereas homologation- functional group interconversion (FGI) generates higher analogues with a change in functionality. This general synthesis strategy may be counted for a number of reasons, such as higher accessibility to the successive homologs, a chance for the introduction of additional functionality, or solely to create a regular series of homologs. The advantages of homologation reactions could be measured by the efficiency, technical simplicity, and regio- and/or stereo-selectivity of the overall operations in a synthetic plan. Homologation reactions constitute powerful and versatile tools for preparative chemistry which uses different concepts underpinning the use of homologating reagents in addition to their applications in organic synthesis. A compilation and comparison of diverse methods available for homologation cum functional group interconversion will empower synthetic chemists to undertake studies that require a series of analogues. In this review, we have categorized and summarized such methods and synthetic applications of one and two-carbon homologation-functionalization of various functional groups in organic synthesis.

Quinoline and pyrimidine are well-known moieties, which appear in various natural and synthetic products. Furthermore, quinoline-pyrimidine-inspired hybrids are known to have several biological properties. In addition, many pyrimido[4,5-b]quinolinone ring systems, specifically concerning medicinal chemistry, have been reported over the past decade. This review depicts the synthesis of pyrimido[4, 5-b] quinolones (PyQs4,5-b) through 6-aminopyrimidin-4-(thi)one derivatives. The preparation of PyQs4,5-b was clarified through the following chemical reactions: Vilsmeier-Haack formylation, Hantzsch-like reaction, and one-pot three-component reaction.

Pathogenic microorganisms cause serious and lethal infectious diseases. Numerous antimicrobial agents have been developed during the last few decades to treat these infectious diseases, but these are still expanding worldwide. Moreover, microorganisms are developing resistance against commercially available medicines. So, antimicrobial resistance is expanding as the most serious health threat particularly in developing countries, due to the easier availability of anti-microbial drugs. Therefore, the scarcity of effective antibiotics suggests the pressing demand for new anti-microbial agents. Modern drug discovery regarded heterocyclic compounds as its core due to their striking structural characteristics. Pyrazole is considered as a significant heterocyclic nucleus in modern drug development. This review brings a considerable summary regarding derivatives of pyrazole developed over the last decade for their anti-microbial action, along with docking studies carrying an expectation that it will be beneficial for medicinal chemists working in anti-microbial drug development.

Among various emerging organofluorine molecules, gem-difluorovinyl sulfonates are attractive building blocks and less used in organic reactions. This review article is concerned with recent advances in organic reactions using gem-difluorovinyl sulfonates in recent years. We discussed the reactions of gem-difluorovinyl sulfonates with aldehydes, amines, imines, amides, boronic acids, aryl halides, etc. or addition, reduction, substitution and intramolecular 1,3-sulfonyl migration of gemdifluorovinyl sulfonates in nine approaches. The synthetic strategies described in this review provided diversely substituted fluorinated molecules.

: Nitriles are employed in many academic and industrial fields, especially organic synthesis. They are crucial precursors to synthesize aldehydes, amines, amides, carboxylic acids, and tetrazoles. There are many routes to synthesize nitriles from various species such as aldehydes, alcohols and amines. This review summarized the recently developed direct conversion of aldehydes to nitriles, focusing on the simple and efficient reaction.

Among the several heterocyclic compounds containing aza- and oxa-heterocycles are predominant due to their abundant biological importance. The nanoparticles have demonstrated excellent catalytic activity under optimum conditions with higher reusability or recyclability and higher yields of synthetic heterocyclic targets. Previously we reviewed the synthesis of aza- and oxa-heterocycles catalyzed by metal nanoparticles (MNPs) during 2009-2019 and published an update of such reports of 2020 on the same subject. With anticipations to the next, the present comprehensive work highlights the synthesis of aza- and oxa-heterocycles catalyzed by MNPs reported during the year 2021 to update the reader of the present work with the most recent trends in selection of MNPs in the synthesis of desired heterocyclic scaffolds.

Quinone diazides are a class of diazo compounds, having a planar six-membered ring system with diazo, carbonyl, and alkene groups in conjugation. It has been used in optical, electronic, and polymer materials. In the last few years, these diazo compounds explored various rearrangements reactions and insertion reactions via the formation of metallo-carbenoids. Recently, it has been used to incorporate phenol moieties into hydrocarbons or arene/heteroarenes systems via transition metalcatalyzed C-H bond activation. The reactions proceed via C-H bond insertion or migratory insertion of metal-carbenes. In many cases, the site-selectivities were obtained by the guidance of various directing groups (removable or non-removable). At the same time, several asymmetric approaches were also studied to incorporate phenol derivatives to arenes/heteroarenes furnishing compounds showing axial chirality with high stereoselectivity. This review will mainly focus on directed regioselective arylation with quinone diazides under transition metal catalysis through C-H bond activation.

This mini-review summarizes the methods available for the synthesis of transition metalsulfur complexes, which have been used as models of metalloprotein active sites, desulfurization catalysts, and organometallic functional materials. All the methods use silicon-sulfur compounds as starting materials, exploiting the selective cleavage of Si—S bond and the subsequent incorporation of sulfur fragments into the metal complex. Mechanistic considerations are also provided. Period covered: 1968 to date.

1-Deoxysphingolipids are a class of sphingolipids which lacks the primary hydroxyl group (C1-OH). Hence, it does not get converted/degraded to complex corresponding products like sphingosine- 1-phosphate (SIP), a pro-mitotic. Enigmol, an orally bioavailable 1-deoxyphingolipid has shown potential against various different types of cancer cells along with impressive cytotoxic/ antiproliferative properties. Due to its unique structural properties, Enigmol and its analogs have attracted considerable attention from synthetic organic chemists. This review provides an overview of all the synthetic approaches being followed for the synthesis of Enigmol and its structural analogs.

: Sensor arrays contain a group of sensors, improve observations with new dimensions, provide better estimations, and additional parameters in comparison to the individual selective sensor. The array-based sensing technique provides good performance to respond to various gaseous or liquid analytes. Room temperature ionic liquids (RTILs) (melting point <25oC) and Group of uniform materials based on organic salts (GUMBOS) (melting point =25-250oC) are organic ionic salts, composed of an oppositely charged pair of bulky organic cations and bulky organic/inorganic anion and shows interesting tunable physicochemical properties. In this review article, we will discuss the sensing performance of ILs- and GUMBOS-based sensor arrays. ILs-based sensor arrays have been used in electrochemical gas sensing, solvent discrimination, colorimetric gas sensing, sensing of organic compounds, optoelectronic sensing of vapors and solutions, and vapour sensing through IL/QCM systems. GUMBOS-based sensor arrays have been employed in vapour sensing through the GUMBOS/QCM method, detection, and discrimination of proteins.

: Diketopiperazines (DKPs) are mainly produced by microorganisms. In recent years, active natural products with DKPs structure have been isolated from marine bacteria, actinomycetes and fungi. The stable six-membered ring framework makes DKPs a vital pharmacophore in medicinal chemistry. Several recent studies have demonstrated that it has antibacterial, antifungal, antiviral, antitumor, immunosuppressive, neuroprotective, anti-malaria, anti-prion, and anti-hyperglycemia properties. Some DKPs are signaling molecules for intercellular communication, which can activate or inhibit bacterial Lux R-mediated quorum sensing. They are considered potential new anti-infective drugs that could control biofilm formation by interfering with information communication between microbes. DKPs possess excellent biological activities and have received extensive attention from medicinal chemistry workers. Bioactivity studies of DKPs have revealed that many highly active lead compounds exist in antibacterial, antitumor, and antiviral fields and in treating neurological disorders. This paper reviews the research progress of diketopiperazines in the past ten years.

Alkoxmethyl heterocycles play a significant role as bioactive compounds in pharmaceutical and bifunctional ligands in synthetic organic chemistry. N-Alkoxmethylation can lead toward multipurpose mixed acetals, natural product precursors, and task-specific functionalized ionic liquids. This report provides a comprehensive account of the synthesis and perspectives applications of alkoxymethyl azaheterocycles. The first part gives a detailed account of the different synthetic strategies employed to access N-alkoxy methyl heterocyclic compounds. The second part deals with their applications, owing to the unique reactivity of the alkoxymethyl group and the nature of heterocycle. Besides diverse biological and synthetic applications, alkoxymethyl benzotriazoles also provide substantial scope as a versatile anion stabilizer that can lead to diverse oxygen functionalities.

: Laccase (Benzenediol: oxygen oxidoreductase; E.C.1.10.3.2), a multicopper oxidase that is a known lignin-degrading enzyme, can catalyse an ample array of substrates, from phenolic, non-phenolic compounds, aromatic amines, diamines, heterocyclic compounds to organic/inorganic metal compounds etc., bestowed they have not too high redox potentials. Despite many laccase-producing organisms like bacteria, insects, plants, and animals, white rot filamentous fungi are the best producers of this enzyme. In the presence of laccase, pesticides (fungicides, herbicides, insecticides, etc.) of various chemical compositions (organophosphates, organochlorines, carbamates, pyrethrin & pyrethroids etc.) are oxidized into the water with collateral reduction of four electrons of molecular oxygen with various efficiencies. Bioremediation efficiency can be increased in the presence of various natural or synthetic mediators, viz. ABTS, violuric acid, 1- hydroxy benzotriazole, vanillin, syringaldehyde, PEG, etc. Immobilized laccase on various supporting materials increased the enzyme's stability, reliability, and reusability for continuous application, particularly for industrial processes. The present review discusses the structure, catalytic cycle, general mechanism of oxidation, and various scopes and challenges of pesticide degradation by this multifaceted biocatalyst which could lead to a green sustainable environment.

As one of the most efficient and cost-effective separation methods, Membrane technology has been mainly considered for different applications. But as with any method, there are some special drawbacks in membranes, such as fouling, concentration polarization, and durability, which can limit the membrane performance in terms of permeate flux and solute rejection. Superamphiphilic polymers have different applications in different fields, including liquid-liquid separation membranes, self-healing, antifouling, self-cleaning, and adsorbent coatings. Recently, these kinds of coatings were applied to different membrane systems, and the effects of coating on the membrane performance were evaluated. As a review, an overview of the most common methods for manufacturing membranes with a superamphiphilic surface, a general review of the explored practical applications of such coatings in membranes, conclusions about the current situation of research, and commercial applications of superamphiphilic membranes are presented in this study.