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Topic Review
Wittig Reactions under Sonication Conditions
Carbonyl olefinations are among the most important organic syntheses that form C=C bonds, as they usually have high yields and in addition offer excellent stereoselectivity. Due to these advantages, carbonyl olefinations have important pharmaceutical and industrial applications. These reactions contain an additional step of an α-functionalized carbanion to an aldehyde or ketone to produce alkenes, but syntheses performed using metal carbene complexes are also known. The Wittig reaction is an example of carbonyl olefination, one of the best ways to synthesize alkenes.
  • 2.8K
  • 28 Jun 2023
Topic Review
Heterogeneous Catalysis for Selective Hydrogenation of Oximes
The synthesis of many biologically active compounds is not complete without transforming the carbonyl group into an amino group, carried out by the reaction of nucleophilic substitution with hydroxylamine at the carbonyl carbon atom and further reduction of the C–N and N–O bonds. This method eliminates nitrating agents that exhibit oxidizing properties and may cause undesirable effects on other structural fragments of complex molecules. Selective hydrogenation of oximes over heterogeneous catalysts is still one of the most useful and challenging reactions in synthetic organic chemistry to obtain amines and hydroxylamines since the 1920s when the Adam’s catalyst was first used for this reaction. 
  • 2.7K
  • 28 Dec 2022
Topic Review
Gold(I)-Catalyzed Approaches with Arylalkyne Activation
Gold catalysts possess the advantages of water and oxygen resistance, with the possibility of catalyzing many novel chemical transformations, especially in the syntheses of small-molecule skeletons, in addition to achieving the rapid construction of multiple chemical bonds and ring systems in one step.
  • 2.7K
  • 14 Feb 2023
Topic Review
Corey-Seebach Reagent in the 21st Century
The Corey-Seebach reagent plays an important role in organic synthesis because of its broad synthetic applications. The Corey-Seebach reagent is formed by the reaction of an aldehyde or a ketone with 1,3-propane-dithiol under acidic conditions, followed by deprotonation with n-butyllithium. A large variety of natural products (alkaloids, terpenoids, and polyketides) can be accessed successfully by utilizing this reagent.
  • 2.7K
  • 30 May 2023
Topic Review
Egyptian Honeybee
The Egyptian honeybee (Apis mellifera lamarckii) is one of the honeybee subspecies known for centuries since the ancient Egypt civilization. The subspecies of the Egyptian honeybee is distinguished by certain traits of appearance and behavior that were well-adapted to the environment and unique in a way that it is resistant to bee diseases, such as the Varroa disease. The subspecies is different than those found in Europe and is native to southern Egypt.
  • 2.7K
  • 21 Oct 2022
Topic Review
Synthesis of the Coumarin Core
Coumarin compounds are attractive organic compounds with many practical applications. Among them there are compounds with biological activity, pharmaceuticals, agrochemicals, dyes, and optoelectronic materials. For this reason, enormous and continuous attempts were made to develop new synthetic pathways and protocols to facilitate the key cyclization reaction of heterocyclic ring and its regioselective functionalization. Of the numerous proposed reactions for the preparation of coumarins, those based on transition metal catalysts have been frequently used recently. Such processes as intramolecular and intermolecular hydroarylation of alkenes or alkynes can be mentioned among the most effective reactions proceeding via the activation of the C–H bond. Knowledge about the mechanistic foundations of catalytic processes seems to be of significant importance in order to improve them and simplify the conditions. Direct functionalization of the coumarin skeleton seems to be one of the more difficult tasks in recent times.
  • 2.6K
  • 23 Mar 2022
Topic Review
Stereoselective Synthesis of Chiral Molecules
Metal/lipase-combo catalyzed dynamic kinetic resolution (DKR) of racemic chiral alcohols is a general and practical process to obtain the corresponding enantiopure esters R with quantitative conversion. The use of known Ru-catalysts as well as newly developed homogeneous and heterogeneous metal catalysts (Fe, V) contributed to make the DKR process more sustainable and to expand the substrate scope of the reaction. In addition to classical substrates, challenging allylic alcohols, tertiary alcohols, C1-and C2-symmetric biaryl diols turned out to be competent substrates. Synthetic utility further emerged from the integration of this methodology into cascade reactions leading to linear/cyclic chiral molecules with high ee through the formation of multiple bonds, in a one-pot procedure. 
  • 2.6K
  • 08 Oct 2021
Topic Review
Acridine
Acridine, an alkaloid from anthracene, also known by the names of 10-azaanthracene, dibenzopyridine, 2,3,5,6-dibenzopyridine, and its derivatives or analogs, have a great potential to be an efficient class of excellent inhibitor. The phenomenon of corrosion threatens metallic components, human safety, and the economy. Despite being eco-friendly and promising as a corrosion inhibitor, acridine has not been explored to its full potential. 
  • 2.6K
  • 09 Nov 2022
Topic Review
1,3-Butadiene
1,3-Butadiene is the organic compound with the formula (CH2=CH)2. It is a colorless gas that is easily condensed to a liquid. It is important industrially as a monomer in the production of synthetic rubber. The molecule can be viewed as the union of two vinyl groups. It is the simplest conjugated diene. Although butadiene breaks down quickly in the atmosphere, it is nevertheless found in ambient air in urban and suburban areas as a consequence of its constant emission from motor vehicles. The name butadiene can also refer to the isomer, 1,2-butadiene, which is a cumulated diene with structure H2C=C=CH−CH3. This allene has no industrial significance.
  • 2.6K
  • 17 Oct 2022
Topic Review Peer Reviewed
Tautomerism of β-Diketones and β-Thioxoketones
The present overview concentrates on recent developments of tautomerism of β-diketones and β-thioxoketones, both in solution and in the solid state. In particular, the latter has been a matter of debate and unresolved problems. Measurements of 13C, 17O, and 2H chemical shifts have been used. Deuterium isotope effects on chemical shifts are proposed as a tool in the study of this problem. Photoconversion of β-diketones and β-thioxoketones are discussed in detail, and the incorporation of β-diketones into molecules with fluorescent properties is assessed. Finally, docking studies of β-diketones are scrutinized with an emphasis on correct tautomeric structures and knowledge about barriers to interconversion of tautomers.
  • 2.6K
  • 13 Mar 2025
Topic Review
Application of Biobased Solvents in Asymmetric Catalysis
The application of the so-called green solvents has emerged as a useful alternative to the classical organic solvents. These solvents must present some properties, such as a low vapor pressure and toxicity, high boiling point and biodegradability, and must be obtained from renewable sources.
  • 2.6K
  • 12 Oct 2022
Topic Review
Coumarin Derivatives from Marine World
Coumarin and its derivatives have significantly attracted the attention of medicinal chemists and chemical biologists due to their huge range of biological, and in particular, pharmacological properties. Interesting families of coumarins have been found from marine sources, which has accelerated the drug discovery process by inspiring innovation or even by the identification of analogues with remarkable biological properties.
  • 2.6K
  • 13 Jan 2023
Topic Review
Coumarin(Benzopyrone)-Fused Five-Membered Aromatic Heterocycles
Coumarins are a family of benzopyrones (1,2-benzopyrones or 2H-[1]benzopyran-2-ones), which represent an important family of oxygen-containing heterocycles, widely distributed in nature. Since coumarins have versatile applications, the synthesis trials of different structures of the coumarin-based scaffold were attempted. Among all the heterocycles built on α-pyrone moiety of coumarin, the furan ring was the only available structure in nature. Thus, it has inspired a lot of researchers to replace the oxygen with other heteroatoms. Wide varieties of heterocycles were constructed by a synthetic pathway to introduced furans, pyrroles, thiophenes, and selenophenes as a fused ring that characterized by a single heteroatom to the α-pyrone moiety of coumarin. 
  • 2.6K
  • 05 Apr 2021
Topic Review
Synthetic methods of phosphonopeptides
Phosphonopeptides are phosphorus analogues of peptides and have been widely applied as enzyme inhibitors and antigens to induce catalytic antibodies. Phosphonopeptides generally contain one aminoalkylphosphonic acid residue and include phosphonopeptides with C-terminal aminoalkylphosphonic acids and phosphonopeptides with a phosphonamidate bond. The phosphonamidate bond in the phosphonopeptides is generally formed via phosphonylation with phosphonochloridates, condensation with coupling reagents and enzymes, and phosphinylation followed by oxidation. Pseudo four-component condensation reaction of amides, aldehydes, alkyl dichlorophosphites, and amino/peptide esters is an alternative, convergent, and efficient strategy for synthesis of phosphonopeptides through simultaneous construction of aminoalkylphosphonic acids and formation of the phosphonamidate bond.
  • 2.5K
  • 16 Dec 2020
Topic Review
The Molecular Electron Density Theory
The Molecular Electron Density Theory (MEDT) was proposed in 2016 as a  contemporary reactivity model in Organic Chemistry against the Frontier Molecular Orbital (FMO) theory.
  • 2.5K
  • 22 Oct 2020
Topic Review
Sharpless Asymmetric Dihydroxylation
Sharpless asymmetric dihydroxylation is an important reaction in the enantioselective synthesis of chiral vicinal diols that involves the treatment of alkene with osmium tetroxide along with optically active quinine ligand. Sharpless introduced this methodology after considering the importance of enantioselectivity in the total synthesis of medicinally important compounds.
  • 2.5K
  • 03 Apr 2023
Topic Review
Fluorinated BODIPY Dyes
The synthesis of fluorine-containing small molecules has had numerous benefits of improving the quality and efficiency of many applications of these compounds. Compounds such as derivatives of boron-dipyrromethene (BODIPY) typically demonstrate signal wavelengths around 500 nm and 600 nm; however, it is more favorable to see these signals closer to 700 nm to improve fluorophore applications. For this reason, recent studies described further in the text demonstrate the applications of adding fluorine-based substituents and phenyl rings to the chemical designs, thus redshifting absorption and fluorescence wavelengths.
  • 2.5K
  • 30 Mar 2021
Topic Review
Pincer Transition Metal Catalysts for Sustainability
Sustainable solutions are needed to avoid global warming and climate change. Homogeneous catalysis might play a fundamental role for this. Pincer-type complexes are promising in terms of stability, selectivity, efficiency and the use of mild reaction conditions. Pincer complexes have been used in many sustainable chemical reactions, for example hydrogen release and upconversion of CO2, N2, and biomass.
  • 2.5K
  • 08 Apr 2022
Topic Review
Three-Component Ring Transformation
The ring transformation is a synthetic method for cyclic products including transfer of the partial structure of a cyclic substrate to a reagent, constructing a new ring system. When one substrate and two reagents are used to form a cyclic structure, it is called three-component ring transformation.
  • 2.5K
  • 10 Mar 2021
Topic Review
Isoquinolone
Isoquinolones (isoquinolin-1(2H)-ones): the atom- and step-economic syntheses.
  • 2.5K
  • 14 Jul 2021
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