نتایج جستجو برای: nucleophile
تعداد نتایج: 1574 فیلتر نتایج به سال:
What does the term "nucleophilic substitution" imply? • A nucleophile is an the electron rich species that will react with an electron poor species • A substitution implies that one group replaces another. Nucleophilic substitution reactions occur when an electron rich species, the nucleophile, reacts at an electrophilic saturated C atom attached to an electronegative group (important), the lea...
The activation of F-BODIPYs with boron trihalides, followed by treatment with a nucleophile, effects facile substitution at boron; using water as the nucleophile promotes deprotective removal of the -BF2 moiety and thereby production of the corresponding parent dipyrrin salt in quantitative yield under extremely mild conditions.
A combination of spectroscopic, chromatographic and computational approaches was employed to investigate the reaction several diselenides with a thiolate nucleophile, leading breaking selenium–selenium (Se–Se) bond.
We herein report on the usefulness of the reactivity indices profiles along a reaction coordinate. The model is tested to fully describe the reaction mechanism of the title reactions. Group nucleophilicity and electrophilicity profiles help describe the bond-breaking/bond-formation processes and the intramolecular electron density reorganization. The reactivity indices' profile analysis is cons...
An enantioselective β-carbon amination for enals is disclosed. The nitrogen atom from a protected hydrazine with suitable electronic properties readily behaves as a nucleophile. Addition of the nitrogen nucleophile to a catalytically generated N-heterocyclic-carbene-bound α,β-unsaturated acyl azolium intermediate constructs a new carbon-nitrogen bond asymmetrically. The pyrazolidinone products ...
[figure: see text] A conceptually new palladium-catalyzed amidation reaction is described for the synthesis of beta-amido ketones based on derailing the Wacker oxidation of enones. This reaction generates a new carbon-nitrogen bond via a palladium-catalyzed conjugate addition of a carbamate nucleophile to an enone. The regiocontrol, mild and neutral conditions, lack of preactivation of the nucl...
Stereoselective synthesis of vinylsilanes by a gold(I)-catalyzed acetylenic sila-cope rearrangement.
Cationic tri-tert-butylphosphinegold(I) serves as a catalyst in the sila-Cope rearrangement of acetylenic allylsilanes. When phenol is employed as a nucleophile, the reaction allows for the stereoselective synthesis of vinylsilanes. Alternatively, use of methanol as a nucleophile leads to cyclic vinylsilanes, which can be viewed as latent vinylsilanes that are revealed on treatment with a mild ...
The Ntn (N terminal nucleophile) hydrolases are a new family of hydrolytic enzymes with a characteristic fold in their catalytic domain. These enzymes act on a range of substrates, cleaving amide or ester bonds by a nucleophilic reaction. The catalytic nucleophile is the oxygen in serine or threonine side chains, or sulphur in the cysteine side chain. The active site is often created by autocat...
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