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Several modifications of alkynylation reactions are known: In the Arens–van Dorp synthesis the compound ethoxyacetylene [7] is converted to a Grignard reagent and reacted with a ketone, the reaction product is a propargyl alcohol.
This alkynylation reaction is enantioselective and involves an alkynylzinc reagent [1] rather than the sodium acetylide used by John Ulric Nef in his 1899 report of the synthetic approach. [ 2 ] [ 3 ] Propargyl alcohols are versatile precursors for the chirally-selective synthesis of natural products and pharmaceutical agents , making this ...
A 3D model of ethyne (), the simplest alkyneIn organic chemistry, an alkyne is an unsaturated hydrocarbon containing at least one carbon—carbon triple bond. [1] The simplest acyclic alkynes with only one triple bond and no other functional groups form a homologous series with the general chemical formula C n H 2n−2.
English: Diagram showing the chemical reaction involving Sonogashira reaction of a phenylalanine derivative with an alkyne. Modified from File:Alkynylation.gif to correct chemical errors. Date
The reaction medium must be basic to neutralize the hydrogen halide produced as the byproduct of this coupling reaction, so alkylamine compounds such as triethylamine and diethylamine are sometimes used as solvents, but also DMF or ether can be used as solvent. Other bases such as potassium carbonate or cesium carbonate are occasionally used.
The Seyferth–Gilbert homologation is a chemical reaction of an aryl ketone 1 (or aldehyde) with dimethyl (diazomethyl)phosphonate 2 and potassium tert-butoxide to give substituted alkynes 3. [ 1 ] [ 2 ] Dimethyl (diazomethyl)phosphonate 2 is often called the Seyferth–Gilbert reagent .
An alkyne trimerisation is a [2+2+2] cycloaddition reaction in which three alkyne units (C≡C) react to form a benzene ring. The reaction requires a metal catalyst. The process is of historic interest as well as being applicable to organic synthesis. [1] Being a cycloaddition reaction, it has high atom economy.
The Corey–Fuchs reaction, also known as the Ramirez–Corey–Fuchs reaction, is a series of chemical reactions designed to transform an aldehyde into an alkyne. [1] [2] [3] The formation of the 1,1-dibromoolefins via phosphine-dibromomethylenes was originally discovered by Desai, McKelvie and Ramirez. [4]