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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.
  • 444
  • 12 Oct 2022
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.
  • 986
  • 25 Nov 2022
Topic Review
Ascorbic Acid-Induced Reactions
Ascorbic acid is the most well-known vitamin found in different types of food. It has tremendous medical applications in several different fields such as in pharmaceuticals, cosmetics, and in organic synthesis. Ascorbic acid can be used as a substrate or mediator in organic synthesis. In this review, we report ascorbic acid-catalyzed reactions in organic synthesis. Several examples are included in this review to demonstrate that ascorbic acid is a versatile catalyst for the synthesis of diverse organic compounds. Reactions catalyzed by ascorbic acid are performed in organic or aqueous media. The readily available and easy handling features of ascorbic acid make these procedures highly fascinating.
  • 2.7K
  • 25 Nov 2020
Topic Review
Ascorbic Acid-Mediated Reactions
Ascorbic acid is a vitamin found in different types of food. It has tremendous medical applications in several different fields such as in pharmaceuticals, cosmetics, and in organic synthesis. 
  • 4.2K
  • 25 Nov 2020
Topic Review
Asymmetric Catalytic Ketimine Mannich Reactions
These ketimines are less electrophilic and thus, arguably, more challenging substrates. 3-Aryl-3-hydroxyisoindolin-1-ones are often employed as stable precursors for the corresponding endocyclic N-carbonyl diaryl ketimines. This class of ketimines is useful synthons to access chiral isoindolin-1-ones that are an important motif found in numerous biologically relevant molecules and natural products.
  • 754
  • 05 Aug 2021
Topic Review
Asymmetric Synthesis of BINOL Derivatives
The chirality resulting from restricted rotation around a single bond is called atropisomerism (axial chirality). This phenomenon was first described by Christie and Kenner in 1922 when investigating the biaryl 6,6’-dinitro-2,2’-diphenic acid, and the term “atropisomer”, derived from the Greek where “a” means “not” and “tropes” means “turn”, was created by Kuhn. Atropisomers belong to the class of axially chiral compounds; however, here, the enantiomers exist due to restricted rotation around a single bond. Axial chirality has also been considered as an important structural element of many natural products and bioactive compounds, whose enantiomers generally exhibit different pharmacological activities and metabolic processes in vivo and in vitro.
  • 847
  • 10 Jan 2023
Topic Review
Atropisomers by Oxidative Aromatization
Atropisomers are fascinating objects of study by themselves for chemists but also find applications in various sub-fields of applied chemistry. Among these strategies, oxidative aromatization with central-to-axial conversion of chirality has gained increasing popularity. It consists of the oxidation of a cyclic non-aromatic precursors into the corresponding aromatic atropisomers.
  • 364
  • 18 Apr 2023
Topic Review
Aurilide Family
Aurilides are a class of depsipeptides occurring mainly in marine cyanobacteria. Members of the aurilide family have shown to exhibit strong cytotoxicity against various cancer cell lines. These compounds bear a pentapeptide, a polyketide, and an α-hydroxy ester subunit in their structure.
  • 628
  • 18 Mar 2021
Topic Review
Benzimidazole and Their Derivatives
Heterocyclic compounds are significant lead drug candidates based on their various structure–activity relationships (SAR), and their use in pharmaceutics is constantly developing. Benzimidazole (BnZ) is synthesized by a condensation reaction between benzene and imidazole. The BnZ structure consists of two nitrogen atoms embedded in a five-membered imide ring which is fused with a benzene ring. 
  • 326
  • 23 Oct 2023
Topic Review
Beta Lactams and Products
Discovery and synthesis of penicillin and other beta-lactam antibiotics have received sustained attention. The use of β-lactam antibiotics is extensively documented in several thousand of publications. In modern times, microwave-induced reactions are also used extensively for the synthesis and stereochemical studies of diverse β-lactams. In this paper, the author describes a few crucial reactions that are performed toward the synthesis of β-lactams and products obtained from them under classical conditions as well as by domestic or automated microwave oven.
  • 1.1K
  • 28 Oct 2020
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