Ethylmagnesium bromide

Chemical Properties

Ethylmagnesium bromide is generally sold as a dark brown solution and can be dissolved in diethyl ether, butyl ether, isopropyl ether, THF and anisole.

Uses

Ethylmagnesium Bromide is a useful reagent in preparation of zirconium complexes having two phenoxy-imine chelate ligands for olefin polymerization.

Preparation

Ethylmagnesium bromide is commercially available, usually as a solution in diethyl ether or tetrahydrofuran. It may be prepared in the normal manner of Grignard reagents — by reacting bromoethane with magnesium in diethyl ether:
EtBr + Mg → EtMgBr

Application

Ethylmagnesium bromide is a Grignard reagent widely used in organic chemical synthesis. It can be employed in the following chemical reactions:
(1) The cleavage effect on pentafluorophenylphosphine bonds and sulphur bonds: Reactions between tri(pentafluorophenyl)phosphine and bis(pentafluorophenyl)sulphide with ethylmagnesium bromide yield products indicating the pentafluorophenyl group detaches from both phosphorus and sulphur^[1].
(2) Reaction with unsaturated organotin compounds to form saturated compounds: Its reaction with tri-n-butylstannylacetylene in diethyl ether removes ethane, ethylene, acetylene, and ethylacetylene, yielding ethyl tri-n-butylstannyl and bis-1,2-tri-n-butylstannyl ethane^[2].
(3) Facilitating selective transformation of cyclopropyl groups: In the case of the tetrahydrofuran-protected racemic diethyl malonate 1, selective conversion of the cyclopropyl group is achieved via a reductive cyclopropanation reaction using ethylmagnesium bromide in the presence of tetrahydrofuran. This ultimately enables the isolation of the ethoxycarbonyl group from diethyl malonate^[3].

Reactions

Ethylmagnesium bromide reacts with water to produce ethane.
CH3CH2MgBr+H2O→CH3-CH3+Mg(OH)Br
Reaction of ethylmagnesium bromide with ethyl acetate in the presence of styrene and titanium(IV) isopropoxide as a catalyst leads to (Z)-1-methyl-2-phenylcyclopropanol in 42% yield.

General Description

Ethylmagnesium bromide, an organomagnesium compound, is commonly known as Grignard reagent. It is a powerful carbon nucleophile mainly used for C-C bond formation. Ethylmagnesium bromide solution (3.0 M in diethyl ether) can be used for copper(I)-catalyzed allylic substitution reaction.
Grignard reagents are organometallic compounds discovered by a French chemist, Victor Grignard in 1900. These compounds can be obtained as a formula “RMgX” by the reaction of halogenated hydrocarbons with magnesium metal in anhydrous solvents such as diethyl ether,1) and have been widely used in organic synthesis.

Hazard

Flammable, dangerous fire risk.

reaction suitability

reaction type: Grignard Reaction

References

[1] STEPHEN A. SICREE Christ T. Cleavage of pentafluorophenyl-phosphorus and -sulfur bonds by ethylmagnesium bromide[J]. Journal of Fluorine Chemistry, 1992, 59 2: Pages 269-273. https://doi.org/10.1016/S0022-1139(00)82419-7.
[2] A. N. NESMEYANOV I. S S A E BORISOV. ChemInform Abstract: REACTIONS OF ETHYLMAGNESIUM BROMIDE WITH SOME UNSATURATED ORGANOTIN COMPOUNDS[J]. ChemInform, 1976, 7 4. https://doi.org/10.1002/chin.197604258.
[3] ANDREI V. BEKISH Oleg G K. Differentiation between the ethoxycarbonyl groups in diethyl malate via their titanium-catalyzed reductive cyclopropanation with ethylmagnesium bromide and subsequent site-selective three-carbon ring cleavage[J]. Tetrahedron Letters, 2005, 46 41: Pages 6975-6978. https://doi.org/10.1016/j.tetlet.2005.08.076.