Synthesis Of Grignard Reagents Research Articles

Process hazard evaluation and exothermic mechanism for the synthesis of n-butylmagnesium bromide Grignard reagent in different solvents

The synthesis of Grignard reagents, which are formed by the reaction of magnesium and organic halides (RX), is hazardous because of the highly exothermic nature of this reaction. In this work, calorimetry and infrared (IR) spectroscopy were used to identify the exothermic mechanism and process hazards for the synthesis of n-butylmagnesium bromide Grignard reagent (n-BuMgBr) in diethyl ether (DE), tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), cyclopentylmethyl ether (CPME), and diethylene glycol butyl ether (DGBE). The latter three solvents were chosen by the substitution principle of the “inherent safety” design concept, which aims to reduce the risk of the target reaction in a fundamental manner. An EasyMax102 calorimeter was used to characterize the exothermic behavior of the reactions using isothermal and isoperibolic experiments carried out in a semi-batch glass reactor coupled with an IR probe to monitor changes in the species and concentrations during the reaction process. An adiabatic TAC-500A calorimeter was also used to understand the adiabatic decomposition behavior of the products obtained in the isothermal experiments under the worst-case (cooling failure and thermal runaway) scenario. Meanwhile, density functional theory calculations were performed to understand the reaction pathway and associated energies based on the experimental data. Further, the risk assessment of thermal runaway was analyzed using a risk matrix and a Stoessel criticality diagram. The results indicate that the risk of the reactions when using 2-MeTHF, CPME, and DGBE are all class 1, making reactions in these solvents inherently safer than those using DE or THF, which were both class-3 risks. These findings provide further evidence that 2-MeTHF, CPME, and DGBE are safer than the typical solvents used for the industrial production of Grignard reagents.

Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel-Hauser amides, and magnesium alkoxides.

Magnesium organometallic reagents occupy a central position in organic synthesis. The freshness of these compounds is the key for achieving a high conversion and reproducible results. Common methods for the synthesis of Grignard reagents from metallic magnesium present safety issues and exhibit a batch-to-batch variability. Tubular reactors of solid reagents combined with solution-phase reagents enable the continuous-flow preparation of organomagnesium reagents. The use of stratified packed-bed columns of magnesium metal and lithium chloride for the synthesis of highly concentrated turbo Grignards is reported. A low-cost pod-style synthesizer prototype, which incorporates single-use prepacked perfluorinated cartridges and bags of reagents for the automated on-demand lab-scale synthesis of carbon, nitrogen, and oxygen turbo magnesium bases is presented. This concept will provide access to fresh organomagnesium reagents on a discovery scale and will do so independent from the operator’s experience in flow and/or organometallic chemistry.

Scalable Continuous Synthesis of Grignard Reagents from in Situ-Activated Magnesium Metal

The continuous synthesis of Grignard reagents has been investigated under continuous processing conditions using Mg turnings at variable liquid throughputs and concentrations. A novel process windo...

Single‐step oxidative homocoupling of aryl Grignard reagents via Co(II), Ni(II) and Cu(II) Complexes under air

A simple catalytic system of direct synthesis for the symmetrical biaryls using catalytic amounts of Co(II), Ni(II) and Cu(II) complexes has been developed. The reaction system involves in situ synthesis of Grignard reagents. The complexes, containing bidentate Schiff base and dmit (2‐thioxo‐1,3‐dithiole‐4,5‐dithiolate) ligands, were compatible with diverse functionalities and afford a high yield of biaryls in a single step, proving to be promising catalysts in homocoupling reactions. Atmospheric oxygen is used as an oxidant which renders a green, simple and economical catalytic route. Copyright © 2014 John Wiley & Sons, Ltd.

ChemInform Abstract: Main Group Conjugated Organic Anion Chemistry. Part 3. Application of Magnesium‐Anthracene Compounds in the Synthesis of Grignard Reagents.

ChemInform Abstract: Main Group Conjugated Organic Anion Chemistry. Part 3. Application of Magnesium‐Anthracene Compounds in the Synthesis of Grignard Reagents.

ChemInform Abstract: Carbanions as Intermediates in the Synthesis of Grignard Reagents.

ChemInformVolume 19, Issue 34 Preparative Organic Chemistry ChemInform Abstract: Carbanions as Intermediates in the Synthesis of Grignard Reagents. H. J. R. DE BOER, H. J. R. DE BOER Scheikd. Lab., Vrije Univ., NL-1081 HV Amsterdam, NiederlandeSearch for more papers by this authorO. S. AKKERMAN, O. S. AKKERMAN Scheikd. Lab., Vrije Univ., NL-1081 HV Amsterdam, NiederlandeSearch for more papers by this authorF. BICKELHAUPT, F. BICKELHAUPT Scheikd. Lab., Vrije Univ., NL-1081 HV Amsterdam, NiederlandeSearch for more papers by this author H. J. R. DE BOER, H. J. R. DE BOER Scheikd. Lab., Vrije Univ., NL-1081 HV Amsterdam, NiederlandeSearch for more papers by this authorO. S. AKKERMAN, O. S. AKKERMAN Scheikd. Lab., Vrije Univ., NL-1081 HV Amsterdam, NiederlandeSearch for more papers by this authorF. BICKELHAUPT, F. BICKELHAUPT Scheikd. Lab., Vrije Univ., NL-1081 HV Amsterdam, NiederlandeSearch for more papers by this author First published: August 23, 1988 https://doi.org/10.1002/chin.198834105Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue34August 23, 1988 RelatedInformation

Main group conjugated organic anion chemistry. 3. Application of magnesium-anthracene compounds in the synthesis of Grignard reagents

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMain group conjugated organic anion chemistry. 3. Application of magnesium-anthracene compounds in the synthesis of Grignard reagentsStephen Harvey, Peter C. Junk, Colin L. Raston, and Geoffrey SalemCite this: J. Org. Chem. 1988, 53, 14, 3134–3140Publication Date (Print):July 1, 1988Publication History Published online1 May 2002Published inissue 1 July 1988https://doi.org/10.1021/jo00249a002RIGHTS & PERMISSIONSArticle Views2871Altmetric-Citations66LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (955 KB) Get e-Alerts Get e-Alerts

Carbanions as Intermediates in the Synthesis of Grignard Reagents

Evidence for the occurrence of R⊖ in reaction (a) is provided by the isolation of compounds such as 2 in the reaction of 1 with Mg in THF after addition of Me3GeCl. On the basis of a series of comparative experiments it could be concluded that a carbanion intermediate is probably responsible for the stannyl migration.

ChemInform Abstract: A Novel, Continuous High-Yield Synthesis of Grignard Reagents.

Abstract A continuous process for the production of Grignard reagents, in particular, allylmagnesium chloride is described. The yield and purity of the Grignard reagent are both significantly higher than those normally obtained by use of conventional batch procedures. Disproportionation of the Grignard reagent to insoluble magnesium chloride presented the major technical problem in the process, though, of course, the yield of active “allyl” is unaffected.

A novel, continuous high-yield synthesis of Grignard reagents

A continuous process for the production of Grignard reagents, in particular, allylmagnesium chloride is described. The yield and purity of the Grignard reagent are both significantly higher than those normally obtained by use of conventional batch procedures. Disproportionation of the Grignard reagent to insoluble magnesium chloride presented the major technical problem in the process, though, of course, the yield of active “allyl” is unaffected.

Magnesium anthracene: an alternative to magnesium in the high yield synthesis of Grignard reagents

Benzylic type di-Grignard reagents (2)–(5) and the mono-Grignard reagent (6) have been prepared by treating the appropriate organic chloride, for (2)–(6), or bromide, for (3) and (4), with magnesium anthracene in tetrahydroguran in yields of, repectively, 92–96%, and 60 and 84%.