Isopropylmagnesium chloride

Last updated
Isopropylmagnesium chloride
IPrMgCl.png
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.012.680 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 213-947-1
PubChem CID
UNII
  • InChI=1S/C3H7.ClH.Mg/c1-3-2;;/h3H,1-2H3;1H;/q-1;;+2/p-1
    Key: IUYHWZFSGMZEOG-UHFFFAOYSA-M
  • C[CH-]C.[Mg+2].[Cl-]
Properties
C3H7ClMg
Molar mass 102.84 g·mol−1
Solubility Ethyl ether
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg
Danger
H225, H260, H314
P210, P223, P231+P232, P233, P240, P241, P242, P243, P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P335+P334, P363, P370+P378, P402+P404, P403+P235, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Isopropylmagnesium chloride is an organometallic compound with the general formula (CH3)2HCMgCl. This highly flammable, colorless, and moisture sensitive material is the Grignard reagent derived from isopropyl chloride. It is commercially available, usually as a solution in tetrahydrofuran.

Contents

Synthesis and reactivity

Solutions of isopropylmagnesium chloride by treating isopropyl chloride with magnesium metal in refluxing ether: [1]

(CH3)2HCCl + Mg → (CH3)2HCMgCl

This reagent is used to prepare other Grignard reagents by transmetalation. [2] An illustrative reaction involves the generation of the Grignard reagent derived from bromo-3,5-bis(trifluoromethyl)benzene: [3]

(CH3)2HCMgCl + (CF3)2C6H3Br → (CH3)2HCCl + (CF3)2C6H3MgBr

Addition of one equivalent of LiCl to isopropylmagnesium chloride gives "Turbo Grignard" solutions, named so due to the increased rate and efficiency for transmetallation reactions. [4] [5]

Isopropylmagnesium chloride is also used to prepare isopropyl compounds, such as chlorodiisopropylphosphine: [6]

PCl3 + 2 (CH3)2CHMgCl → [(CH3)2CH]2PCl + 2 MgCl2

This reaction exploits the bulky nature of the isopropyl substituent.

Turbo-Grignard reagents

As initially reported by Knochel et al., [7] lithium chloride, isopropylmagnesium chloride enhances the ability of isopropylmagnesium chloride toward transmetalation reactions. The more reactive species, a LiCl-iPrMgCl complex, is called a Turbo-Grignard reagent. These species are related to Turbo-Hauser bases, a family of magnesium amido compounds containing also LiCl. [8] "Turbo-Grignards", as they are often called, are aggregates with the formula [i-PrMgCl·LiCl]2. These species promote formation of aryl and heteroaryl Grignard reagents by halogen-magnesium exchange: [9]

fast, homogeneous: XC6H4Br + i−PrMgCl·LiCl → XC6H4MgCl·LiCl + i−PrCl + MgBrCl

The traditional method for generating the aryl Grignard reagent proceeds less predicably:

slow, heterogeneous: XC6H4Br + Mg → XC6H4MgBr

Furthermore, traditional routes to Grignard reagents has limited functional group compatibility, whereas Turbo-Grignard method tolerates other halides, some ester groups, and nitriles.

Related Research Articles

<span class="mw-page-title-main">Grignard reaction</span> Organometallic coupling reaction

The Grignard reaction is an organometallic chemical reaction in which, according to the classical definition, carbon alkyl, allyl, vinyl, or aryl magnesium halides are added to the carbonyl groups of either an aldehyde or ketone under anhydrous conditions. This reaction is important for the formation of carbon-carbon bonds.

In organic chemistry, an aryl halide is an aromatic compound in which one or more hydrogen atoms, directly bonded to an aromatic ring are replaced by a halide. The haloarene are different from haloalkanes because they exhibit many differences in methods of preparation and properties. The most important members are the aryl chlorides, but the class of compounds is so broad that there are many derivatives and applications.

Metalation is a chemical reaction that forms a bond to a metal. This reaction usually refers to the replacement of a halogen atom in an organic molecule with a metal atom, resulting in an organometallic compound. In the laboratory, metalation is commonly used to activate organic molecules during the formation of C—X bonds, which are necessary for the synthesis of many organic molecules.

The Hiyama coupling is a palladium-catalyzed cross-coupling reaction of organosilanes with organic halides used in organic chemistry to form carbon–carbon bonds. This reaction was discovered in 1988 by Tamejiro Hiyama and Yasuo Hatanaka as a method to form carbon-carbon bonds synthetically with chemo- and regioselectivity. The Hiyama coupling has been applied to the synthesis of various natural products.

The Corey–House synthesis (also called the Corey–Posner–Whitesides–House reaction and other permutations) is an organic reaction that involves the reaction of a lithium diorganylcuprate () with an organic halide or pseudohalide () to form a new alkane, as well as an ill-defined organocopper species and lithium (pseudo)halide as byproducts.

<span class="mw-page-title-main">Grignard reagent</span> Organometallic compounds used in organic synthesis

Grignard reagents or Grignard compounds are chemical compounds with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH3 and phenylmagnesium bromide (C6H5)−Mg−Br. They are a subclass of the organomagnesium compounds.

<span class="mw-page-title-main">Organozinc chemistry</span>

Organozinc chemistry is the study of the physical properties, synthesis, and reactions of organozinc compounds, which are organometallic compounds that contain carbon (C) to zinc (Zn) chemical bonds.

<span class="mw-page-title-main">Group 2 organometallic chemistry</span>

Group 2 organometallic chemistry refers to the chemistry of compounds containing carbon bonded to any group 2 element. By far the most common group 2 organometallic compounds are the magnesium-containing Grignard reagents which are widely used in organic chemistry. Other organometallic group 2 compounds are rare and are typically limited to academic interests.

<span class="mw-page-title-main">Tetramethyltin</span> Chemical compound

Tetramethyltin is an organometallic compound with the formula (CH3)4Sn. This liquid, one of the simplest organotin compounds, is useful for transition-metal mediated conversion of acid chlorides to methyl ketones and aryl halides to aryl methyl ketones. It is volatile and toxic, so care should be taken when using it in the laboratory.

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<span class="mw-page-title-main">Organosilver chemistry</span> Study of chemical compounds containing carbon-silver chemical bonds

Organosilver chemistry is the study of organometallic compounds containing a carbon to silver chemical bond. The theme is less developed than organocopper chemistry.

<span class="mw-page-title-main">Organocerium chemistry</span>

Organocerium chemistry is the science of organometallic compounds that contain one or more chemical bond between carbon and cerium. These compounds comprise a subset of the organolanthanides. Most organocerium compounds feature Ce(III) but some Ce(IV) derivatives are known.

Hauser bases, also called magnesium amide bases, are magnesium compounds used in organic chemistry as bases for metalation reactions. These compounds were first described by Charles R. Hauser in 1947. Compared with organolithium reagents, the magnesium compounds have more covalent, and therefore less reactive, metal-ligand bonds. Consequently, they display a higher degree of functional group tolerance and a much greater chemoselectivity. Generally, Hauser bases are used at room temperature while reactions with organolithium reagents are performed at low temperatures, commonly at −78 °C.

<span class="mw-page-title-main">Phenylsodium</span> Chemical compound

Phenylsodium C6H5Na is an organosodium compound. Solid phenylsodium was first isolated by Nef in 1903. Although the behavior of phenylsodium and phenyl magnesium bromide are similar, the organosodium compound is very rarely used.

Radical fluorination is a type of fluorination reaction, complementary to nucleophilic and electrophilic approaches. It involves the reaction of an independently generated carbon-centered radical with an atomic fluorine source and yields an organofluorine compound.

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<span class="mw-page-title-main">Diethylphosphite</span> Chemical compound

Diethyl phosphite is the organophosphorus compound with the formula (C2H5O)2P(O)H. It is a popular reagent for generating other organophosphorus compounds, exploiting the high reactivity of the P-H bond. Diethyl phosphite is a colorless liquid. The molecule is tetrahedral.

Paul Knochel is a French chemist and a member of the French Academy of Sciences.

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References

  1. Seyferth, Dietmar (2009-03-23). "The Grignard Reagents". Organometallics. 28 (6): 1598–1605. doi:10.1021/om900088z. ISSN   0276-7333.
  2. Knochel, P.; Dohle, W.; Gommermann, N.; Kneisel, F. F.; Kopp, F.; Korn, T.; Sapountzis, I.; Vu, V. A. (2003). "Highly Functionalized Organomagnesium Reagents Prepared through Halogen–Metal Exchange". Angewandte Chemie International Edition. 42 (36): 4302–4320. doi:10.1002/anie.200300579. PMID   14502700.
  3. Johnnie L. Leazer Jr; Raymond Cvetovich (2005). "A Practical and Safe Preparation of 3,5-Bis(trifluoromethyl)acetophenone". Org. Synth. 82: 115. doi:10.15227/orgsyn.082.0115.
  4. Krasovskiy, Arkady; Knochel, Paul (2004-06-21). "A LiCl‐Mediated Br/Mg Exchange Reaction for the Preparation of Functionalized Aryl‐ and Heteroarylmagnesium Compounds from Organic Bromides". Angewandte Chemie International Edition. 43 (25): 3333–3336. doi:10.1002/anie.200454084. ISSN   1433-7851.
  5. Hermann, Andreas; Seymen, Rana; Brieger, Lukas; Kleinheider, Johannes; Grabe, Bastian; Hiller, Wolf; Strohmann, Carsten (2023-06-19). "Comprehensive Study of the Enhanced Reactivity of Turbo‐Grignard Reagents**". Angewandte Chemie International Edition. 62 (25). doi: 10.1002/anie.202302489 . ISSN   1433-7851.
  6. W. Voskuil; J. F. Arens (1968). "Chlorodiisopropylphosphine". Org. Synth. 48: 47. doi:10.15227/orgsyn.048.0047.
  7. Krasovskiy, A.; Knochel, P. (2004). "A LiCl-Mediated Br/Mg Exchange Reaction for the Preparation of Functionalized Aryl- and Heteroarylmagnesium Compounds from Organic Bromides". Angew. Chem. Int. Ed. 43 (25): 3333–3336. doi:10.1002/anie.200454084. PMID   15213967.
  8. Li-Yuan Bao, Robert; Zhao, Rong; Shi, Lei (2015). "Progress and Developments in the turbo Grignard Reagent i-PrMgCl·LiCl: A Ten-Year Journey". Chemical Communications. 51 (32): 6884–6900. doi:10.1039/c4cc10194d. PMID   25714498.
  9. Knochel, Paul; Gavryushin, Andrei (2010). "Lithium Dichloro(1-methylethyl)-magnesate". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn01161. ISBN   978-0-471-93623-7.