n-Propylmagnesium bromide

n-Propylmagnesium bromide
Identifiers
CAS Number	927-77-5;
3D model (JSmol)	Interactive image;
ChemSpider	10265325;
ECHA InfoCard	100.011.967
EC Number	213-162-4;
PubChem CID	101916;
CompTox Dashboard (EPA)	DTXSID00918999 ;
	InChI InChI=1S/C3H7.BrH.Mg/c1-3-2;;/h1,3H2,2H3;1H;/q-1;;+2/p-1 Key: UGVPKMAWLOMPRS-UHFFFAOYSA-M;
	SMILES CC[CH2-].[Mg+2].[Br-];
Properties
Chemical formula	C3H7BrMg
Molar mass	147.298 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

n-Propylmagneisum bromide, often referred to as simply propylmagnesium bromide, is an organomagnesium compound with the chemical formula C₃H₆MgBr. As the Grignard reagent derived from 1-bromopropane, it is used for the n-propylation of electrophiles in organic synthesis.^[1]

Properties

Like all Grignard reagents, propylmagnesium bromide is a strong electrophile, sensitive to both water and air.

The propylmagnesium halides are the simplest Grignard reagents to exhibit isomerism. Isopropylmagnesium chloride is the primary synthetic equivalent of the isopropyl group.^[1]

n-Propylmagnesium bromide is soluble in ether, tetrahydrofuran, and toluene.^[2]

Synthesis

Synthesis is analogous to other saturated alkyl Grignard reagents. A solution of 1-bromopropane in ether - typically diethyl ether or tetrahydrofuran - is treated with magnesium, which inserts itself into the organohalogen bond. As both the magnesium metal and the product are sensitive to water, the reaction must take place in anhydrous conditions.^[3]

C₃H₆−Br + Mg → C₃H₆−Mg−Br

While the product is often portrayed as simply C₃H₆MgBr, in reality it will quickly form a tetrahedral coordination complex with the Lewis basic solvent, centred on the magnesium atom:

C₃H₆MgBr + 2 (C₂H₅)₂O → C₃H₆Mg((C₂H₅)₂O)₂Br

C₃H₆MgBr + 2 (CH₂)₄O → C₃H₆Mg((CH₂)₄O)₂Br

Applications

Propylmagnesium bromide is used in the Grignard reaction to introduce propyl groups to nucleophiles.^[1]

References

^ ^a ^b ^c Maruyama, Kazuhiro; Matano, Yoshihiro; Katagiri, Toshimasa (August 1991). "Product-determining factors in the grignard reactions of benzophenones. The role of the structure of alkyl groups in grignard reagents". Journal of Physical Organic Chemistry. 4 (8): 501–515. doi:10.1002/poc.610040806.
^ Macintyre, Jane E. (10 November 1994). Dictionary of Organometallic Compounds. CRC Press. p. 2275. ISBN 978-0-412-43060-2.
^ Canonne, P.; Foscolos, G.; Caron, H.; Lemay, G. (January 1982). "Etude de l'influence du diluant hydrocarbone dans la reaction des organomagnesiens primaires sur les cetones encombrees". Tetrahedron. 38 (24): 3563–3568. doi:10.1016/0040-4020(82)80061-6.

[maru-1] Maruyama, Kazuhiro; Matano, Yoshihiro; Katagiri, Toshimasa (August 1991). "Product-determining factors in the grignard reactions of benzophenones. The role of the structure of alkyl groups in grignard reagents". Journal of Physical Organic Chemistry. 4 (8): 501–515. doi:10.1002/poc.610040806.

[2] Macintyre, Jane E. (10 November 1994). Dictionary of Organometallic Compounds. CRC Press. p. 2275. ISBN 978-0-412-43060-2.

[3] Canonne, P.; Foscolos, G.; Caron, H.; Lemay, G. (January 1982). "Etude de l'influence du diluant hydrocarbone dans la reaction des organomagnesiens primaires sur les cetones encombrees". Tetrahedron. 38 (24): 3563–3568. doi:10.1016/0040-4020(82)80061-6.

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