Solid-state supercapacitor with impressive performance characteristics,assembled using redox-mediated gel polymer electrolyte

Journal of Solid State Electrochemistry - A solid-state supercapacitor is assembled using redox-mediated gel polymer as the electrolyte and separator and coconut shell–derived,...     

Facile and efficient sulfenylation method using quinone mono-O,S-acetals under mild conditions

A novel sulfenylation method induced by aromatization of quinone mono-O,S-acetals is described. These sulfenylation reagents readily react with silyl enolethers or electron rich aromatic compounds to give sulfenylation products under mild conditions. In particular, O,S-acetal 2j, which possesses a pentafluorophenylthio function, is the most effective reagent from the standpoint of the adaptability for various substrates.     

An efficient dehyrohalogenation method for the synthesis of α,β,β-trifluorostyrenes, α-chloro-β,β-difluorostyrenes and E-1-arylperfluoroalkenes

Dehydrofluorination of 1-aryl-1,2,2,2-tetrafluoroethanes (ArCHFCF₃) and 1-aryl-1-chloro-2,2,2-trifluoroethane (ArCHClCF₃) using lithiumhexamethyldisilazide (LHMDS) in tetrahydrofuran (THF) at room temperature produced 1,2,2-trifluorostyrene and 1-chloro-2,2-difluorostyrene, respectively, in very good isolated yields. Dehydrofluorination of 1,2,2,3,3,3-hexafluoro-1-phenyl-propane (PhCHFCF₂CF₃) and 1,2,2,3,3,4,4,4-octafluoro-1-phenyl-butane (PhCHFCF₂CF₂CF₃) using LHMDS produced the corresponding substituted olefins (1-phenyl-1,2,3,3,3-pentafluoroprop-1-ene and 1-phenyl-1,2,3,3,4,4,4-pentafluorobut-1-ene) in good yield and high E-selectivity. Dehydrofluorination of 1-chloro-1-phenyl-2,2,3,3,3-pentafluoropropane (PhCHClCF₂CF₃) and 1-chloro-1-phenyl-2,2,3,3,4,4,4-heptafluorobutane (PhCHClCF₂CF₂CF₃) produced a mixture of the corresponding E and Z olefins (PhCClCFCF₃ and PhCClCFCF₂CF₃) in good yield.     

Association of Molybdenum Ionic Species with Alumina Surface

The adsorption isotherms at 25, 45, and 65 degrees C of molybdenum solutions of concentration ranges between 10(-3) and 3x10(-2) M(Mo) (pH 4-5) on different alumina samples are investigated. The analysis is conducted using a modified Frumkin isotherm which takes a more realistic account of the lateral interaction between adsorbed species and considers that the adsorption takes place on the most basic OH groups on the surface of alumina. The results are discussed in view of the difference in solutions speciation, and the changes in the pH of the remaining supernatant solutions. The solution temperature, PZC of the used aluminas, the configuration of the basic OH groups on their surface, and the pore structure have been shown to intervene effectively. Copyright 2000 Academic Press.     

Development of a General and Efficient Iron‐Catalyzed Epoxidation with Hydrogen Peroxide as Oxidant

The development of inexpensive and practical iron catalysts for the environmentally benign epoxidation of olefins with hydrogen peroxide as terminal oxidant is described. By systematic variation of ligands, metal sources, and reaction conditions, it was discovered that FeCl₃?6H₂O in combination with pyridine‐2,6‐dicarboxylic acid and different amines shows high reactivity and excellent selectivity towards the epoxidation of aromatic olefins and moderate reactivity towards that of aliphatic olefins.     

An overview of palladium-catalyzed synthesis of seven-membered heterocycles

Heterocyclic compounds are the ones that have always remained in the limelight owing to their superior contributions toward various disciplines such as biology, medicine, material science, pharmaceutical science, industry and so on. They form the building blocks of DNA and RNA macromolecules. Suitable tuning of these heterocyclic compounds can result in chemotherapeutic moieties with superlative efficiency. Seven-membered heterocyclic compounds are an important class of heterocyclic chemistry. Some of them are azepine, oxepine, thiepine, diazepine, thiazepine and so on. Transition metal-catalyzed synthesis of heterocycles has been the most explored in the recent past. Palladium is known as the best suitable catalyst for the same and that is the result of its excellent functional group tolerance and catalytic potency. Here, we intend to summarize the various investigations made on the palladium-catalyzed synthesis of seven-membered heterocycles. To the best of our knowledge, this is the first review in this topic and covers literature up to 2020.     

Recent advances in the iron-catalysed multicomponent reactions

Iron-catalysed reactions are widely used in organic synthesis owing to its benefits over other metals. Among the important organic reactions, multicomponent reactions play a significant role due to its greener aspects like high atom economy, minimal amount of by-product, economic feasibility etc. For the past few years, iron-catalysed multicomponent reactions have attracted the attention of several chemists which lead to the invention of some fine chemistry. The majority of iron-catalysed multicomponent reactions results in the synthesis of heterocyclic compounds having biologically active natural products, pharmaceutical etc. These developments in the iron-catalysed multicomponent reactions are the focus of this review. This is the first review in this topic which covers the literature up to 2020, and it encompasses the different methods for the synthesis of acyclic, carbocyclic and heterocyclic compounds.     

Solid-phase synthesis of new ribo and deoxyribo BrdU probes for labeling and detection of nucleic acids

A facile and efficient solid-phase synthesis of BrdU-14-UTP and BrdU-14-dUTP is reported. The method involves a nucleophilic addition of CPG-supported Br-dU with a 5′-carboxy modifier amidite, followed by the coupling with AA-UTP or AA-dUTP and finally the solid-support is cleaved under basic conditions. The newly prepared non-radioactive probes may have important applications in immunocytochemistry spatially in labeling and detection assays. BrdU moiety is coupled with nucleotides like dUTP and UTP and incorporated into nucleic acids using generally available polymerase like Taq polymerase or RNA polymerase. The probes thus generated can be used in standard blotting and hybridization procedures including in situ hybridization and detection with anti-BrdU conjugates.     

Direct estimation of 90Sr in water samples of spent fuel storage bay using partial counting rate technique

The direct estimation of ⁹⁰Sr by β counting from a mixture of other β and γ emitter is often difficult due to the efficiency variation among the β-emitters and the unknown nature of the sample. This paper deals with use of a combination of β and γ spectrometry measurements in estimating the activity of ⁹⁰Sr, pure β emitter from a mixture of other β–γ emitters in water samples. This procedure offers a simple, easy to use, rapid and a reliable method for ⁹⁰Sr estimation as an alternative to the tedious radiochemical separation procedure in this specific case.     

Efficient Synthesis of New Peptidyl Chloromethyl Ketones for the Application of Proteinase K Inhibitors

The synthesis of a new series of peptidyl chloromethyl ketones such as MeOSuc-Ala-Ala-Pro-Ile-CH₂Cl (AAPI) and MeOSuc-Ala-Ala-Ala-Pro-Ile-CH₂Cl (AAAPI) is described.