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	AllRefer.com - Grignard reagent (Organic Chemistry) - Encyclopedia
		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 Grignard, a French chemist, who received a Nobel Prize (1912) for their discovery.
	reference.allrefer.com /encyclopedia/G/Grignard-r.html (294 words)

	Grignard reaction - Wikipedia, the free encyclopedia
		Victor Grignard (University Of Lyons, France) was awarded the 1912 Nobel Prize in Chemistry for the discovery of such reagents.
		The disadvantage of the Grignard reagent is that they readily react with protic solvents (such as water), or functional groups with protons, such as alcohols and amines.
		Grignard reagents are formed by reacting the appropriate alkyl or aryl halide with magnesium metal.
	en.wikipedia.org /wiki/Grignard_reagent (826 words)

	Preparation of Phenylmagnesium Bromide
		The Grignard reagent is prepared by reacting magnesium metal with an alkyl or aryl halide, using an ether as solvent, equation 1.
		Grignard reagents exist in a rapid equilibrium with dialkyl- or diarylmagnesium and the corresponding magnesium halide, equation 2.
		The Grignard reagent is a strong base; it will remove protons from materials that are more acidic than alkanes or alkenes, i.e., water, alcohols, terminal alkynes, amines, etc. Thus, it is imperative that the bromobenzene and ether be rigorously dried (Na) prior to use.
	www.bradley.edu /las/chm/Course/351/Grignardweb2.htm (1190 words)

	Grignard Reaction (Site not responding. Last check: 2007-10-14)
		A Grignard reaction is prepared by adding an alkyl halide to a cold mixture of magnesium metal in an ether solvent (anhydrous, for water will react with the Grignard reagent and destroy it).
		The resulting reagent, "RMgX" is a very polar reagent and a very strong Lewis base and therefore will be easily protonated by water, which acts as a strong acid in contact with a Grignard reagent.
		A carboxylic acid was synthesized by the addition of dry ice (CO) to the reagent and subsequent protonation of the adduct.
	www.chemistry.emory.edu /mccormick/reports/grignard.htm (1094 words)

	Grignard Victor
		Grignard was the son of a sail maker.
		1.Synthesis of the Grignard reagent: an organomagnesium compound (the Grignard reagent) is made reacting an organohalide (R-X, where R stands for some alkyl, acyl, or aryl radical and X is a halogen such as usually bromine or iodine) with magnesium metal dissolved in diethyl ether.
		The resulting compound, named a Grignard reagent, has the general chemical formula R-Mg-X. 2.Attack on the carbonyl: A ketone or an aldehyde (both contain a carbonyl group) is added to the solution containing the Grignard reagent.
	www.thebestedu.com /bookmarks/chem/grignard-victor.htm (288 words)

	INTRODUCTION (Site not responding. Last check: 2007-10-14)
		Grignard reagents cannot be isolated without a solvent present, such as ether, and hace the general formula RMgX.
		Reaction of Grignard with a formaldehyde produces a primary alcohol, with an aldehyde produces a seconadey alcohol, and with a ketone produces a tertiary alcohol.
		In the Grignard reagent the Carbon is very basic and water can donate a proton to the carbon, destroying the nucleophilic character of the Grignard.
	www.neiu.edu /~jhramire/Grignard/introduction.htm (211 words)

	Chemical Reactivity
		Grignard reagents require an ether solvent for their formation, and have been crystallized as monomeric and dimeric ether complexes.
		The 2-butenyl-1- magnesium bromide (crotyl Grignard) on the left in equation 23 is in equilibrium with a smaller amount of its 1-butenyl-3-magnesium bromide isomer.
		The initial adduct of this Grignard reagent is a stable salt, which may eliminated by treatment with acid or by exchange of magnesium with an alkali metal cation.
	www.cem.msu.edu /~reusch/VirtualText/orgmetal.htm (6204 words)

	Highbeam Encyclopedia - Search Results for Grignard,
		Grignard reagent GRIGNARD REAGENT [Grignard reagent], 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
		Victor Grignard Ancestor of Organic Synthesis: Victor Grignard was a brilliant French chemist who became famous at age 29 for the discovery of the organomagnesium halides and their versatility in chemical synthesis.
	www.encyclopedia.com /SearchResults.aspx?Q=Grignard, (448 words)

	Grignard Experiment
		The Grignard reaction if an example of a class of reactions in which the carbon skeleton of a molecule is modified through the formation of a new carbon-carbon bond.
		The Grignard reaction is typical of a large class of "Organometallic" reactions in that the Grignard reagent acts as a source of nucleophilic carbon which forms a new carbon-carbon bond by attacking a relatively electron deficient or electropositive carbon of a second reactant.
		You can stop the Grignard procedure at this point, but if you decided to continue you must go on through the completion of the extraction to the point where the product is over a drying agent.
	www.sonoma.edu /users/t/trowbrda/336/grignard.html (1005 words)

	Grignard Synthesis
		In the early part of the 20th century, Victor Grignard, a French organic chemist (the French pronunciation of his name can be approximated as "greenyard") studied the reactions of bromoalkanes with magnesium metal.
		If we look at the product of our shorthand description and remember that the addition of a Grignard reagent makes a new carbon-carbon bond in which one of the carbons is attached to an OH group, we can see that there are two such bonds (thicker and longer in the drawing) in our product molecule.
		We remember that the bond came from an unshared electron pair on the Grignard reagent, and that the carbonyl carbon is electrophilic, so we show the appropriate charges.
	chemistry2.csudh.edu /rpendarvis/grignard.html (1716 words)

	grignard reagents
		This page takes an introductory look at how Grignard reagents are made from halogenoalkanes (haloalkanes or alkyl halides), and introduces some of their reactions.
		The reactions between the various sorts of carbonyl compounds and Grignard reagents can look quite complicated, but in fact they all react in the same way - all that changes are the groups attached to the carbon-oxygen double bond.
		The Grignard reagent can therefore serve as a nucleophile because of the attraction between the slight negativeness of the carbon atom in the Grignard reagent and the positiveness of the carbon in the carbonyl compound.
	www.chemguide.co.uk /organicprops/haloalkanes/grignard.html (1297 words)

	Grignard Reagents (Site not responding. Last check: 2007-10-14)
		Grignard noted that alkyl halides react with magnesium metal in diethyl ether (Et O) to form compounds that contain a metal-carbon bond.
		Grignard reagents such as CH MgBr are best thought of as hybrids of ionic and covalent Lewis structures.
		Perhaps the most important aspect of the chemistry of Grignard reagents is the ease with which this reaction allows us to couple alkyl chains.
	chemed.chem.purdue.edu /genchem/topicreview/bp/2organic/grignard.html (373 words)

	aldehydes and ketones with grignard reagents
		It is mainly a duplication of the information on these same reactions from a page on Grignard reagents in the section on properties of halogenoalkanes.
		A Grignard reagent has a formula RMgX where X is a halogen, and R is an alkyl or aryl (based on a benzene ring) group.
		Grignard reagents are made by adding the halogenoalkane to small bits of magnesium in a flask containing ethoxyethane (commonly called diethyl ether or just "ether").
	www.chemguide.co.uk /organicprops/carbonyls/grignard.html (826 words)

	Alkyl Halide Reactivity
		A useful application of these reagents is their ability to couple with alkyl, vinyl and aryl iodides, as shown in the second equation.
		The solution structure of the Simmons-Smith reagent is less well understood than that of the Grignard reagent, but the formula given here is as useful as any that have been proposed.
		The stability and usefulness of the Simmons-Smith reagent may be attributed in part to the higher covalency of the carbon-zinc bond together with solvation and internal coordination of the zinc.
	www.cem.msu.edu /~reusch/VirtualText/alhalrx4.htm (1426 words)

	Week 8 (Grignard Reaction)
		The amount of Grignard reagent is 11.2 mmol (8 mL*1.4 M), while only 2.4 mmol (500 mg/212 g/mol) of benzoin is added.
		Theoretically, 4.8 mmol of Grignard reagent are needed because each benzoin molecule uses up two equivalents (see mechanism in reader).
		The additional Grignard is used to compensate for some moisture in the system and the side reaction with the dichloromethane.
	www.chem.ucla.edu /~bacher/General/30BL/problems/key/key8Sp06.html (634 words)

	Process for producing 1-(p-prenylphenyl)ethanol - Patent 4436939
		As a result, we hit upon an idea of reacting a Grignard reagent, obtained by the reaction of p-chloroprenylbenzene reagent with metallic magnesium, with acetaldehyde, and experimentally performed this reaction.
		The reaction of the Grignard reagent with acetaldehyde is carried out at a temperature of generally between about -40.degree.
		Under these conditions, the reaction between the Grignard reagent and acetaldehyde proceeds very rapidly, and so long as temperature control is possible, the reaction can be terminated almost instantaneously, for example, in less than several minutes.
	www.freepatentsonline.com /4436939.html (2846 words)

	Untitled Document
		The reaction of a Grignard Reagent with an aldehyde or ketone results in a secondary or tertiary alcohol that has a chiral centre.
		[25] Current approaches to optically pure alcohols are by the following methods: (a) the reduction of ketones with chiral aluminium alkoxides, magnesium alkoxides or Grignard reagents (b) the reduction of ketones with chiral metal hydride reagents (c) the hydrogenation of ketones using a rhodium(I) complex as a catalyst.
		The TADDOL reagent 1.28 was the Fluka reagent of the year in 1995 for its unparalleled stereocontrol on the addition of allyl nucleophiles to aldehydes.
	www.chem.ox.ac.uk /ectoc-3/grignard2.html (542 words)

	[No title]
		Summary of the Theory behind the Grignard reagent: The Grignard reagent is an organomagnesium halide that is nucleophilic and it possesses a highly polarized bond between a carbon and a metal.
		Carbonyl groups are the most widespread group in organic chemistry and because of the high polarization of the Grignard reagent, it readily attacks at their electrophilic carbon forming a carbon-carbon bond.
		A Grignard reagent can be seen as follows: The oxidation-reduction reaction of the Grignard reagent occurs on the surface of the metal and it occurs in 2 phases (heterogeneous).
	www.gpc.edu /~lstrange/2642lab/samplelabs/Grignard.doc (912 words)

	Grignard Reaction With an Aldehyde (Site not responding. Last check: 2007-10-14)
		In this experiment, the addition of a nucleophilic Grignard reagent (1-methylbutylmagnesium bromide), to the electrophilic carbonyl carbon of an aldehyde (propanal) is described.
		Because it is possible to vary the structure of both the Grignard reagent and the aldehyde, a wide variety of 2° alcohols is prepared by this route.
		The procedure says (preparation of Grignard reagent, section 4): "The evolution of tiny bubbles from the surface of the magnesium is evidence of reaction.
	www.owlnet.rice.edu /~chem215/Grignard.html (1529 words)

	Grignard Reactions of Nitriles in Benzene
		In the present communication, we describe the first results of our performed reasearch of nitriles at ambient temperature, with the Grignard reagent, prepared in benzene in the presence of one equivalent of diethyl ether (table 1).
		The formation of the complex supposes the coordination of the magnesium of the organomagnesium reagent with the nitrile and consequently, the displacement of one equivalent of solvent, in the case of diethyl ether, that play a role determining in the sequence of the reaction.
		The new method, that is the focus of this work, rest on the preparation of the organomagnesium reagent in hydrocarbon solvents and their subsequent usage with the nitriles is of important value both from an academic or practical viewpoint.
	www.erowid.org /archive/rhodium/chemistry/grignardnitrile.html (742 words)

	[No title]
		Conversion of an organic halide into a Grignard reagent completely transforms the reactive character of the organic compound.
		The Grignard reagent is a very reactive nucleophile and base.
		In this experiment you will make the Grignard reagent phenyl magnesium bromide; this reagent will then be treated with carbon dioxide to form benzoic acid.
	wwwchem.csustan.edu /CHEM3022/GRIGNARD.HTM (1226 words)

	Chemistry 211 Experiment 2
		The organic portion of the Grignard reagent functions as a carbanion nucleophile.
		The Grignard reagent must be used the day it is prepared, and the Day 1 section for each experiment must be performed the same day you made the Grignard reagent.
		When the phenylmagnesium bromide has cooled to room temperature, transfer about half of the Grignard reagent (keep the remaining half in the reaction vessel for reaction in Part B) as quickly as possible to a beaker containing about 5 g of crushed dry ice (excess dry ice is not a problem, as it will sublime).
	www.miracosta.edu /home/dlr/211exp2.htm (2523 words)

	Aldehydes from Grignard reagents with formic acid
		Recently, a striking solvent effect of THF on Grignard reactions with acid chlorides was observed.
		In the preliminary investigation, the reaction of two moles of hexylmagnesium bromide with a mole of formic acid in THF was carried out, and a satisfactory yield (72%) of heptanal was obtained.
		Thus, pure (E)-cinnamaldehyde was prepared from the Grignard reagent from either (E) or (Z)-beta-bromostyrene by hydrolysis with 2N HCl after the reaction.
	www.erowid.org /archive/rhodium/chemistry/grignard.formic.html (1303 words)

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