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Topic Review
Phosphorus-Substituted Pyridines
Phosphorus(V)-substituted pyridine was first synthesized by Plazek’s research group in 1936 by a reaction of 2-dimethylaminopyridine with phosphorus trichloride under oxidative conditions. Later, related compounds were obtained by reactions of metalated pyridines with phosphorus-halogen compounds, of pyridinediazonium tetrafluoroborate with phosphorus trichloride, of N-alkoxypyridines with sodium diethyl phosphite and phosphines, and of N-pyridylpyridines with phosphonic acid, by the Michaelis–Arbuzov reaction, Pd(II)-catalyzed phosphorylation of halopyridines, cyclization of phosphorus-containing 3-azatrienes, and the Diels–Alder reaction involving 3-phosphoryl-1-azadienes.
  • 2.2K
  • 20 Mar 2023
Topic Review
Hydrosilylation Reactions Catalyzed by Rhenium
Hydrosilylation is a very versatile transformation consisting of the addition of a hydrosilane (H-SiR3) to an unsaturated bond. Organosilicon compounds have found widespread applications in our daily lives in silicon-based materials such as silicon rubbers, adhesives, paper release coating, and so forth. In addition, hydrosilylation is an atom economic reaction to access valuable organosilane intermediates for fine chemical synthesis
  • 2.2K
  • 20 May 2021
Topic Review
Organic-Photovoltaics with Efficiency over 17%
When narrow band gap, non fullerene material Y6 or its derivatives are used as electron acceptors, the power conversion efficiency (PCE) of organic photovoltaic (OPV) has exceeded 18%. The PCE improvement of OPV is due to strong photon collection and low energy loss in the near-infrared range. At the same time, the ternary strategy is generally considered to be a convenient and effective means to improve the PCE of OPVs.
  • 2.2K
  • 26 Aug 2021
Topic Review
Diels–Alder Cycloaddition Reactions
Diels–Alder cycloaddition reaction is one of the most powerful strategies for the construction of six-membered carbocyclic and heterocyclic systems, in most cases with high regio- and stereoselectivity. An insight into the most relevant advances on sustainable Diels–Alder reactions since 2010 is provided. Various environmentally benign solvent systems are discussed, namely bio-based derived solvents, polyethylene glycol, deep eutectic solvents, supercritical carbon dioxide, water and water-based aqueous systems.
  • 2.1K
  • 25 Mar 2022
Topic Review
Hydrogen Sources in Catalytic Transfer Hydrogenation
Catalytic transfer hydrogenation has emerged as a pivotal chemical process with transformative potential in various industries. Unlike conventional direct hydrogenation, catalytic transfer hydrogenation offers numerous advantages, such as enhanced safety, cost-effective hydrogen donors, byproduct recyclability, catalyst accessibility, and the potential for catalytic asymmetric transfer hydrogenation, particularly with chiral ligands. Alcohols such as methanol and isopropanol are prominent hydrogen donors, demonstrating remarkable efficacy in various reductions. Formic acid offers irreversible hydrogenation, preventing the occurrence of reverse reactions, and is extensively utilized in chiral compound synthesis. Unconventional donors such as 1,4-cyclohexadiene and glycerol have shown a good efficiency in reducing unsaturated compounds, with glycerol additionally serving as a green solvent in some transformations. 
  • 2.1K
  • 14 Nov 2023
Topic Review
Palladium-Catalyzed Carboxylation Reactions
The efficient incorporation of carbon dioxide into an organic substrate (carboxylation) under catalytic conditions to give high value added molecules is one of the most important and fascinating areas of current organic synthesis. Carbon dioxide is a nonflammable, inexpensive and largely available C-1 feedstock. In fact, it allows converting an important waste (it is well known that carbon dioxide is produced in enormous amounts from the combustion of fossil fuels for the production of energy) into a variety of useful compounds, which can find application as fuels or in the pharmaceutical or material fields.
  • 2.1K
  • 06 Jan 2022
Topic Review
Polyester-Based Coatings for Corrosion Protection
Polyesters are synthetic resins formed by an esterification chemical reaction with some occurring naturally. In addition, there are different orientations of polyesters and, hence, different classifications. The classifications aid in determining the processing, curing kinetics, and overall applications of the resin. Saturated, unsaturated polyesters (UPs) and alkyd resins are the main classifications of polyesters; however, vinyl esters are also classified as polyesters since they have a di-ester group. Vinyl esters are based on the combination of an epoxy resin with an unsaturated polymer; they have excellent properties when compared to saturated, unsaturated-type polyesters and alkyd resins. Developments of non-toxic polyester-based coatings have the potential to address a wide range of pollution problems, such as air pollution and water pollution, generated during the production of conventional polyester coatings. The anticorrosion properties of polyester resin modified by nanocomposites intended for steel are of interest. The goal is to produce a bio-based polyester coating with minimal cost by implementing natural products as well as modifying with nanomaterials. 
  • 2.1K
  • 04 Nov 2022
Topic Review
Molecular Iodine-Catalyzed Reactions
Department of Mathematics and Natural Sciences, College of Sciences and Human Studies, Deanship of Research, Prince Mohammad Bin Fahd University, Al Khobar 31952, KSA; Email: bimalbanik10@gmail.com; bbanik@pmu.edu.sa In continuation of our research on the synthesis of diverse organic molecules, we report here molecular iodine-catalyzed diverse synthetic processes. These methods are efficient and produce products in high yield. The success of molecular iodine-catalyzed reactions depends on the release of hydroiodic acid in the reaction media.
  • 2.1K
  • 01 Jun 2020
Topic Review
Synthesis of Ilamycins/Rufomycins and Cyclomarins
Ilamycins/rufomycins and cyclomarins are marine cycloheptapeptides containing unusual amino acids. Produced by Streptomyces sp., these compounds show potent activity against a range of mycobacteria, including multidrug-resistant strains of Mycobacterium tuberculosis. The cyclomarins are also very potent inhibitors of Plasmodium falciparum. Biosynthetically the cyclopeptides are obtained via a heptamodular nonribosomal peptide synthetase (NRPS) that directly incorporates some of the nonproteinogenic amino acids. A wide range of derivatives can be obtained by fermentation, while bioengineering also allows the mutasynthesis of derivatives, especially cyclomarins. Other derivatives are accessible by semisynthesis or total synthesis, reported for both natural product classes.
  • 2.1K
  • 03 Sep 2021
Topic Review
Aromatic Hydrocarbon
An aromatic hydrocarbon or arene (or sometimes aryl hydrocarbon) is a hydrocarbon with sigma bonds and delocalized pi electrons between carbon atoms forming a circle. In contrast, aliphatic hydrocarbons lack this delocalization. The term "aromatic" was assigned before the physical mechanism determining aromaticity was discovered, and referred simply to the fact that many such compounds have a sweet or pleasant odour; however, not all aromatic compounds have a sweet odour, and not all compounds with a sweet odour are aromatic. The configuration of six carbon atoms in aromatic compounds is called a "benzene ring", after the simplest possible such hydrocarbon, benzene. Aromatic hydrocarbons can be monocyclic (MAH) or polycyclic (PAH). Not all aromatic compounds are benzene-based; aromaticity can also manifest in heteroarenes, which follow Hückel's rule (for monocyclic rings: when the number of its π electrons equals 4n + 2, where n = 0, 1, 2, 3, ...). In these compounds, at least one carbon atom is replaced by one of the heteroatoms oxygen, nitrogen, or sulfur. Examples of non-benzene compounds with aromatic properties are furan, a heterocyclic compound with a five-membered ring that includes a single oxygen atom, and pyridine, a heterocyclic compound with a six-membered ring containing one nitrogen atom.
  • 2.1K
  • 25 Nov 2022
Topic Review
Bio-catalysis in Multicomponent Reactions
Enzyme catalysis is a very active research area in organic chemistry, because biocatalysts are compatible with and can be adjusted to many reaction conditions, as well as substrates. Their integration in multicomponent reactions (MCRs) allows for simple protocols to be implemented in the diversity-oriented synthesis of complex molecules in chemo-, regio-, stereoselective or even specific modes without the need for the protection/deprotection of functional groups.
  • 2.1K
  • 28 Dec 2020
Topic Review
Synthetic Applications of Aziridinium Ions
Aziridines are three-membered cyclic organic heterocyclic compounds with one nitrogen atom in the ring. 
  • 2.1K
  • 27 Apr 2021
Topic Review
Iridium-Catalyzed Difunctionalization of Alkenes
Alkenes and their related analogs are a class of ideal starting materials for the construction of complex molecules, because they are readily available in bulk quantities from renewable resources and petrochemical feedstocks. They are also considered to be the most cost-effective and widely used raw material for organic synthesis, and due to the diversity of functional groups, they are used very frequently in different chemical industries. As basic functionalities, the exploration of efficient methods for the selective functionalization of alkenes has been a continuous pursuit throughout the history of organic chemistry.
  • 2.0K
  • 12 Jul 2023
Topic Review
Yucca Saponins. Bioactivity and analytical methods
Yucca is one of the main sources of steroidal saponins, hence different extracts are commercialized for use as surfactant additives by beverage, animal feed, cosmetics or agricultural products. For a deeper understanding of the potential of the saponins that can be found in this genus, an exhaustive review of the structural characteristics, bioactivities and analytical methods that can be used with these compounds has been carried out, since there are no recent reviews on the matter. Thus, a total of 108 saponins from eight species of the genus Yucca have been described.
  • 2.0K
  • 08 Oct 2021
Topic Review
Heating's Influence Trans Fatty Acid in Oils
Consumption of trans fatty acids (TFA) is associated with adverse health outcomes and places a considerable burden on morbidity and mortality globally. TFA may be generated by common cooking practices and hence contribute to daily dietary intake. Heating edible oils to common cooking temperatures (≤200 °C) has minimal effect on TFA generation whereas heating to higher temperatures can increase TFA level. 
  • 2.0K
  • 24 May 2022
Topic Review
Copper Complexes as Topoisomerases Inhibitors
Organometallics, such as copper compounds, are cancer chemotherapeutics used alone or in combination with other drugs. A group of copper complexes exerts an effective inhibitory action on topoisomerases, which participate in the regulation of DNA topology. Copper complexes of topoisomerase inhibitors work by different molecular mechanisms that have repercussions on the cell cycle checkpoints and death effectors. 
  • 2.0K
  • 14 Oct 2020
Topic Review
Sesquiterpenoids Specially Produced by Fungi
Fungi are widely distributed in the terrestrial environment, freshwater, and marine habitat. Only approximately 100,000 of these have been classified although there are about 5.1 million characteristic fungi all over the world. These eukaryotic microbes produce specialized metabolites and participate in a variety of ecological functions, such as quorum detection, chemical defense, allelopathy, and maintenance of symbiosis. Fungi therefore remain an important resource for the screening and discovery of biologically active natural products. Sesquiterpenoids are arguably the richest natural products from plants and micro-organisms. The rearrangement of the 15 high-ductility carbons gave rise to a large number of different skeletons. At the same time, abundant structural variations lead to a diversification of biological activity. 
  • 1.9K
  • 06 Dec 2021
Topic Review
Methods of Lysergic Acid Synthesis
Ergot is the spore form of the fungus Claviceps purpurea. Ergot alkaloids are indole compounds that are biosynthetically derived from L-tryptophan and represent the largest group of fungal nitrogen metabolites found in nature. The common part of ergot alkaloids is lysergic acid. 
  • 1.9K
  • 01 Dec 2022
Topic Review
Synthesis of Squaraine Dyes
Squaraine dye is a popular class of contrast near-infrared (NIR) dyes. Squaraine dyes have shown the ability to be modified with various heterocycles. The indole moiety is the most notable heterocycle incorporated in squaraine dyes.
  • 1.9K
  • 26 Sep 2023
Topic Review
Antimicrobial Activity of Calixarenes/Related Macrocycles
Calixarenes have been shown to have antimicrobial effects since the 1950s. These properties are exemplified through their applications as prodrugs, drug delivery agents and biofilm inhibitors. A particularly important development in recent years has been their ability to engage in multivalent interactions with proteins, thus inhibiting cellular aggregation.
  • 1.9K
  • 12 Dec 2020
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