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Topic Review
Thiosugars of Biological Significance
Thiosugars are important compounds because of their structural complexity and crucial biological activities. Therefore, a series of methods are developed for their synthesis using new methods. Unlike, oxygen sugars, thiosugars are more stable and therefore, much scope exists to alter their structures by chemical manipulations. Notably, thiosugars can act as glycosyl donors as well as acceptors.  Many functionalized thiosugars occur naturally and are potential targets for therapeutics. Synthesis of thiosugars following convergent route is a challenge.  Over the years, scientists have explored thiosugars through numerous green and sustainable methods. These studies are highly significant and timely since it opens the door towards carbohydrate-based drugs.
  • 2.5K
  • 25 Nov 2020
Topic Review
Paan
Paan (from Sanskrit: पर्ण, romanized: parṇá, lit. leaf, cognate with English fern) is a preparation combining betel leaf with areca nut widely consumed throughout South Asia and East Asia (mainly Taiwan). It is chewed for its stimulant effects. After chewing, it is either spat out or swallowed. Paan has many variations. Slaked lime (chuna) paste is commonly added to bind the leaves. Some preparations in the Indian subcontinent include katha paste or mukhwas to freshen the breath. Magahi paan is an expensive variety of betel which is grown in Aurangabad, Gaya and Nalanda districts of central Bihar. It is non-fibrous, sweeter, tastier and the softest of the lot. The origin and diffusion of betel chewing originates from and is closely tied to the Neolithic expansion of the Austronesian peoples. It was spread to the Indo-Pacific during prehistoric times, reaching Near Oceania at 3,400 to 3,000 BP; South India and Sri Lanka by 3,500 BP; Mainland Southeast Asia by 3,000 to 2,500 BP; Northern India by 1500 BP; and Madagascar by 600 BP. From India, it was also spread westwards to Persia and the Mediterranean. Paan (under a variety of names) is also consumed in many other Asian countries and elsewhere in the world by some Asian emigrants, with or without tobacco. It can be an addictive and stimulating formulation with adverse health effects, both with and without tobacco. The spit from chewing betel nuts, known as "buai pekpek" in Papua New Guinea, is often considered an eyesore. Because of this, many places have banned selling and chewing "buai".
  • 2.4K
  • 30 Sep 2022
Topic Review
Furfuryl Alcohol
Furfuryl alcohol (FuOH, C4H3OCH2OH, 2-furylmethanol, 2-furancarbinol) has applications in the fabrication of foundry resins, the ingredient production of P-series fuels, in liquid alkanes and in food production. It is also a very important intermediate in fine chemical synthesis and the polymer industry, and it is used as a chemical intermediate for the synthesis of lysine, vitamin C and levulinic acid and employed as a lubricant and as a dispersing agent.
  • 2.4K
  • 10 Oct 2020
Topic Review
Principles of the Suzuki Coupling Reaction
The Suzuki coupling is a transition metal-catalyzed, cross-coupling carbon–carbon (C–C) bond forming reaction between organic boron compounds and organic halides. As an operationally simple and versatilely applicable procedure, the Suzuki coupling reaction has found immense applications in drug discovery and development in the pharmaceutical industry. 
  • 2.4K
  • 06 Jan 2023
Topic Review
Structure and Chemistry of 3(5)-Substituted Pyrazoles
Pyrazoles are known as versatile scaffolds in organic synthesis and medicinal chemistry, often used as starting materials for the preparation of more complex heterocyclic systems with relevance in the pharmaceutical field. Pyrazoles are also interesting compounds from a structural viewpoint, mainly because they exhibit tautomerism. This phenomenon may influence their reactivity, with possible impact on the synthetic strategies where pyrazoles take part, as well as on the biological activities of targets bearing a pyrazole moiety, since a change in structure translates into changes in properties. Investigations of the structure of pyrazoles that unravel the tautomeric and conformational preferences are therefore of upmost relevance. 3(5)-Aminopyrazoles are largely explored as precursors in the synthesis of condensed heterocyclic systems, namely pyrazolo[1,5-a]pyrimidines.
  • 2.4K
  • 04 Jul 2022
Topic Review
Amadori Rearrangement Products
Flavor is one of the most important factors in attracting consumers and maximizing food quality, and the Maillard reaction (MR) is highly-involved in flavor formation. However, Maillard reaction products have a big drawback in their relatively low stability in thermal treatment and storage. Amadori rearrangement products (ARPs), MR intermediates, can alternatively act as potential flavor additives for their better stability and fresh flavor formation ability.
  • 2.2K
  • 18 Jan 2023
Topic Review
Tropylium Ion
The tropylium ion is a non-benzenoid aromatic species that works as a catalyst. This chemical entity brings about a large number of organic transformations, such as hydroboration reactions, ring contraction, the trapping of enolates, oxidative functionalization, metathesis, insertion, acetalization, and trans-acetalization reactions. The tropylium ion also functions as a coupling reagent in synthetic reactions. This cation’s versatility can be seen in its role in the synthesis of macrocyclic compounds and cage structures.
  • 2.2K
  • 01 Jun 2023
Topic Review
The Phosphorus Bond
The phosphorus bond in chemical systems, which is an inter- or intramolecular noncovalent interaction, occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a covalently or coordinately bonded phosphorus atom in a molecular entity and a nucleophile in another, or the same, molecular entity. It is the second member of the family of pnictogen bonds, formed by the second member of the pnictogen family of the periodic table. 
  • 2.2K
  • 07 Mar 2022
Topic Review
Thiazoles and Bisthiazoles
Thiazole, a five-membered heteroaromatic ring, is an important scaffold of a large number of synthetic compounds. Its diverse pharmacological activity is reflected in many clinically approved thiazole-containing molecules, with an extensive range of biological activities, such as antibacterial, antifungal, antiviral, antiparasitic, antitumor, antiparkinsonian, and anti-inflammatory effects.
  • 2.2K
  • 29 Mar 2021
Topic Review
Michael Addition of Carbonyl Compounds to α,β-Unsaturated Nitroalkenes
The proline-catalyzed asymmetric Michael addition reaction of acetaldehyde with α,β-unsaturated nitroalkenes as synthetically useful routes to β-substituted derivatives of γ-Aminobutyric acid (GABA).
  • 2.2K
  • 01 Jul 2022
Topic Review
Alcohol
In chemistry, alcohol is an organic compound that carries at least one hydroxyl functional group (−OH) bound to a saturated carbon atom. The term alcohol originally referred to the primary alcohol ethanol (ethyl alcohol), which is used as a drug and is the main alcohol present in alcoholic drinks. An important class of alcohols, of which methanol and ethanol are the simplest members, includes all compounds for which the general formula is CnH2n+1OH. Simple monoalcohols that are the subject of this article include primary (RCH2OH), secondary (R2CHOH) and tertiary (R3COH) alcohols. The suffix -ol appears in the IUPAC chemical name of all substances where the hydroxyl group is the functional group with the highest priority. When a higher priority group is present in the compound, the prefix hydroxy- is used in its IUPAC name. The suffix -ol in non-IUPAC names (such as paracetamol or cholesterol) also typically indicates that the substance is an alcohol. However, many substances that contain hydroxyl functional groups (particularly sugars, such as glucose and sucrose) have names which include neither the suffix -ol, nor the prefix hydroxy-.
  • 2.1K
  • 27 Oct 2022
Topic Review
Amino Acid
α-Amino acids find widespread applications in various areas of life and physical sciences. Their syntheses are carried out by a multitude of protocols, of which Petasis and Strecker reactions have emerged as the most straightforward and most widely used.
  • 2.0K
  • 04 Feb 2022
Topic Review
Multicomponent Bargellini Reaction
The multicomponent reaction between phenol, chloroform and acetone is known as Bargellini reaction. In this  article we collected and discussed all the Bargellini and Bargellini-like reactions carried out over the years. The main goal is that this knowledge-sharing will help chemists to properly use this transformation and imagine novel reactivities based on it.
  • 2.0K
  • 08 Mar 2021
Topic Review
CO2 Hydroboration
The use of CO2 as C1 building block for chemical synthesis is receiving growing attention, due to the potential of this simple molecule as abundant and cheap renewable feedstock. Among the possible reductants used in the literature to bring about CO2 reduction to C1 derivatives, hydroboranes have found various applications, in the presence of suitable homogenous catalysts. The main results obtained since 2016 in the synthetic design of main group, first and second row transition metals for use as catalysts for CO2 hydroboration are summarized.
  • 2.0K
  • 04 Jun 2024
Topic Review
Catalytic Synthesis of Glycerol Carbonate
Glycerol carbonate (GC) belongs to the family of organic carbonates that are regarded as very typical “green chemistry” products for their unique advantages in many fields, such as high boiling point solvents, pharmaceutical intermediates, and material intermediates.
  • 2.0K
  • 10 Feb 2022
Topic Review
Synthesis and Properties of Pyrazoles
Pyrazole derivatives are a special class of N-heterocyclic compounds (NHCps) bearing a heteroaromatic five-membered ring with two adjacent nitrogen atoms in the annular structure, one pyrrole-type (proton donor) and one pyridine-type (proton acceptor). Pyrazoles can act as weak bases or acids, with possible strength highly dependent on the nature of their substituent groups. The other three positions in the ring permit structural variants starting from the appropriate precursors or using post-functionalization reactions once the pyrazole ring is formed; these variations give the pyrazoles diverse and valuable synthetical, biological, and photophysical properties; indeed, more complex structures with various relevant examples can be formed from them.
  • 2.0K
  • 09 Sep 2022
Topic Review
Betulinic Acid
Betulinic acid (BA, 3β-hydroxy-lup-20(29)-en-28-oic acid) is a pentacyclic triterpene acid present predominantly in Betula ssp. (Betulaceae) and is also widely spread in many species belonging to different plant families. BA presents a wide spectrum of remarkable pharmacological properties, such as cytotoxic, anti-HIV, anti-inflammatory, antidiabetic and antimicrobial activities, including antiprotozoal effects.
  • 1.9K
  • 24 May 2021
Topic Review
Synthesis of β-Lactams
Stereoselective synthesis of cis and trans β-lactams under diverse conditions is performed.  Numerous conditions are used for this study. The formation of β-lactam depends on the conditions of the experiments, structures of the imines and acid chlorides, order of addition of the reagents, reaction temperature, and solvents. A few mathematical graphs are plotted to explain the results.   
  • 1.9K
  • 25 Nov 2020
Topic Review
Phosphorus fire retardants for polystyrene
Polystyrene, despite its high flammability, is widely used as a thermal insulation material for buildings, for food packaging, in electrical and automotive industries, etc. A number of modification routes have been explored to improve the fire retardance and boost the thermal stability of commercially important styrene-based polymeric products. The earlier strategies mostly involved the use of halogenated fire retardants. Nowadays, these compounds are considered to be persistent pollutants that are hazardous to public and environmental health. Many well-known halogen-based fire retardants, regardless of their chemical structures and modes of action, have been withdrawn from built environments in the European Union, USA, and Canada. This had triggered a growing research interest in, and an industrial demand for, halogen-free alternatives, which not only will reduce the flammability but also address toxicity and bioaccumulation issues. Among the possible options, phosphorus-containing compounds have received greater attention due to their excellent fire-retarding efficiencies and environmentally friendly attributes. Numerous reports were also published on reactive and additive modifications of polystyrene in different forms, particularly in the last decade; hence, the current article aims to provide a critical review of these publications. The authors mainly intend to focus on the chemistries of phosphorous compounds, with the P atom being in different chemical environments, used either as reactive, or additive, fire retardants in styrene-based materials. The chemical pathways and possible mechanisms behind the fire retardance are discussed in this review.
  • 1.8K
  • 26 Aug 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.
  • 1.7K
  • 22 Oct 2020
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