Grignard reagent


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Grignard reagent

(grēnyärd` rēā`jənt), any of an important class of extremely reactive chemical compounds used in the synthesis of hydrocarbons, alcohols, carboxylic acids, and other compounds. Chemically, a Grignard reagent is an organic magnesium halide dissolved in a nonreactive solvent (typically dry ethyl ether). The substance is made up of an organic group, e.g., an alkyl or aryl group, joined by a highly polar covalent bond (see chemical bondchemical bond,
mechanism whereby atoms combine to form molecules. There is a chemical bond between two atoms or groups of atoms when the forces acting between them are strong enough to lead to the formation of an aggregate with sufficient stability to be regarded as an
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) to magnesium, while the magnesium is joined by an ionic bond to a halogen ion, e.g., bromide or iodide. A Grignard reagent will react with water, oxygen, carbon dioxide, or almost any electrophilic organic compound. The reaction of Grignard reagents with aldehydes to form alcohols is of particular importance in the laboratory. Because Grignard reagents are so unstable, they are generally prepared just before use by reacting an organic halide, e.g., methyl iodide, with magnesium metal in a completely dry solvent; air is usually excluded from the reaction vessel, e.g., by flushing it with nitrogen. Grignard reagents are named after Victor GrignardGrignard, Victor
, 1871–1935, French chemist. He shared the 1912 Nobel Prize in Chemistry with Paul Sabatier for his work in organic synthesis based on his discovery (1900) of the Grignard reagent. He taught at the Univ. of Nancy (1909–19) and at the Univ. of Lyons (from 1919).
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, a French chemist, who received a Nobel Prize (1912) for their discovery.

Grignard reagent

[grin′yär rē‚ā·jənt]
(organic chemistry)
RMgX The organometallic halide formed in the Grignard reaction; an example is C2H5MgCl; it is useful in organic synthesis.
References in periodicals archive ?
The substitution of fluorine with an ethynyl anion can be accomplished by using a lithium organometallic reagent, Scheme 2, or a Grignard reagent, Scheme 3.
2006; Goze & Ziessel 2007), ethynyl nucleophiles reveal that only the disubstituted product can be produced when using a lithium reagent (Scheme 2), while either the monosubstituted or disubstituted product can be produced when using a Grignard reagent (Scheme 3).
Thus, the formation of the monosubstituted product prevails when using a Grignard reagent at 0[degrees]C.
For a monosolvated Grignard reagent in toluene under pseudo-first-order conditions, the concentration of the free ether is negligible and the reaction can be rewritten as
After the reaction mixture had cooled down the concentration of the Grignard reagent was determined.
The Specialty Chemicals group will be focusing on their Grignard reagents used as homogenous catalysis and coupling chemistry.
Since the area of organomagnesium chemistry continues to grow far beyond the classical Grignard Reagents, this is an essential resource to help the reader keep abreast of the latest developments.
Catalytic enantioselective conjugate addition and allylic alkylation reactions using Grignard reagents
ECAs of Organolithium Reagents, Grignard Reagents, and Examples of Cu-Catalyzed ECAs