New Solvents (new + solvent)

Distribution by Scientific Domains

Selected Abstracts

ChemInform Abstract: An Efficient, Rapid, and Regioselective Bromination of Anilines and Phenols with 1-Butyl-3-methylpyridinium Tribromide as a New Reagent/Solvent under Mild Conditions.

CHEMINFORM, Issue 23 2009
Sanjay P. Borikar
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Solvent effects on chemical processes: new solvents designed on the basis of the molecular,microscopic properties of (molecular solvent,+,1,3-dialkylimidazolium) binary mixtures

P. M. Mancini
Abstract The purpose of this work was to analyze the microscopic feature of binary solvent systems formed by a molecular solvent (acetonitrile or dimethylformamide or methanol) and an ionic liquid (IL) cosolvent [1-(1-butyl)-3-methylimidazolium tetrafluoroborate or 1-(1-butyl)-3-methylimidazolium hexafluorophosphate]. The empirical solvatochromic solvent parameters ET(30), ,*, ,, and , were determined from the solvatochromic shifts of adequate indicators. The behavior of the solvent systems was analyzed according to their deviation from ideality. The study focused on the identification of solvent mixtures with relevant solvating properties in order to select mixed solvents with particular characteristics. The comparison of the molecular,microscopic solvent parameters corresponding to the selected binary mixtures with both ILs considered at similar mixed-solvent composition revealed that the difference is centered on the basic character of them. A kinetic study of a nucleophilic aromatic substitution reaction between 1-fluoro-2,4-dinitrobenzene (FDNB) and 1-butylamine (BU) developed in (acetonitrile or dimethylformamide,+,IL) solvent mixtures is presented in order to investigate and compare the solvent effects on a chemical process. For the explored reactive systems the solvation behavior is dominated by both the dipolarity/polarizability and the basicity of the media, contributing these solvent properties to accelerating the chemical process. Copyright 2007 John Wiley & Sons, Ltd. [source]

Ionic liquids: solvent properties and organic reactivity

Cinzia Chiappe
Abstract Ionic liquids are a fascinating class of novel solvents, which are attracting attention as possible ,green' alternative to volatile molecular organic solvents to be applied in catalytic and organic reactions and electrochemical and separation processes. Over 200 room temperature ionic liquids are known but for most of them physico-chemical data are incomplete or lacking. Furthermore, despite the incredible number of potential ionic liquids (evaluated as ,>,1014), generally only a few imidazolium-based salts are used in synthesis. Moreover, most of the data reported to date were focused on the effect that these new solvents have on chemical reaction products; only a few reports evidence the effect on reaction mechanisms or rate or equilibrium constants. In this review, the physico-chemical properties of the most used ionic liquids, that are relevant to synthesis, are discussed and a decided emphasis is placed on those properties that most clearly illuminate the ability of ionic liquids to affect the mechanistic aspects of some organic reactions. Copyright 2004 John Wiley & Sons, Ltd. [source]

Combining Enabling Techniques in Organic Synthesis: Continuous Flow Processes with Heterogenized Catalysts

Andreas Kirschning Prof. Dr.
Abstract The concepts article describes enabling techniques (solid-phase assisted synthesis, new reactor design, microwave irradiation and new solvents) in organic chemistry and emphasizes the combination of several of them for creating new synthetic technology platforms. Particular focus is put on the combination of immobilized catalysts as well as biocatalysts with continuous flow processes. In this context, the PASSflow continuous flow technique fulfils both chemical as well as chemical engineering requirements. It combines reactor design with optimized, monolithic solid phases as well as reversible immobilization techniques for performing small as well as large scale synthesis with heterogenized catalysts under continuous flow conditions. [source]