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{{DISPLAYTITLE:''n''-Butyllithium}} |
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{{chembox |
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{{chembox |
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| verifiedrevid = 444019527 |
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| verifiedrevid = 445283361 |
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| Name = ''n''-Butyllithium |
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| Name = 2-Furoic Acid |
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| ImageFile = Butyllithium-hexamer-from-xtal-3D-balls-A.png |
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| ImageFile = File:Furan-2-carboxylic acid 200.svg |
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| ImageSize = 200px |
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| ImageSize = |
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| PIN = Furan-2-carboxylic acid<ref name=iupac2013>{{cite book | title = Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book) | publisher = ] | date = 2014 | location = Cambridge | page = 746 | doi = 10.1039/9781849733069-FP001 | isbn = 978-0-85404-182-4| chapter = Front Matter }}</ref> |
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| ImageCaption = ''n''-Butyllithium hexamer |
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| OtherNames = {{unbulleted list|2-Furoic acid| Pyromucic acid| 2-Furancarboxylic acid| α-Furancarboxylic acid| α-Furoic acid| 2-Carboxyfuran}} |
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| ImageName = 3D ball-and-stick model of ''n''-butyllithium |
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|Section1={{Chembox Identifiers |
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| IUPACName = butyllithium, tetra-μ<sub>3</sub>-butyl-tetralithium |
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| Beilstein = 110149 |
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| OtherNames = NBL, BuLi,<br />1-lithiobutane |
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| ChEBI_Ref = {{ebicite|correct|EBI}} |
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| Section1 = {{Chembox Identifiers |
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| ChEBI = 30845 |
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| ChEBI_Ref = {{ebicite|correct|EBI}} |
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| SMILES = OC(=O)C1=CC=CO1 |
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| ChEBI = 51469 |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| SMILES = CCCC |
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| ChemSpiderID = 10251740 |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| Gmelin = 3056 |
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| ChemSpiderID = 10254339 |
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| KEGG = C01546 |
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| InChI = 1/C4H9.Li/c1-3-4-2;/h1,3-4H2,2H3;/rC4H9Li/c1-2-3-4-5/h2-4H2,1H3 |
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| InChI = 1/C4H9.Li/c1-3-4-2;/h1,3-4H2,2H3;/rC4H9Li/c1-2-3-4-5/h2-4H2,1H3 |
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| InChIKey = MZRVEZGGRBJDDB-NESCHKHYAE |
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| InChIKey = MZRVEZGGRBJDDB-NESCHKHYAE |
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| StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
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| StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
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| StdInChI = 1S/C4H9.Li/c1-3-4-2;/h1,3-4H2,2H3; |
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| StdInChI = 1S/C5H4O3/c6-5(7)4-2-1-3-8-4/h1-3H,(H,6,7) |
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| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
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| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
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| StdInChIKey = MZRVEZGGRBJDDB-UHFFFAOYSA-N |
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| StdInChIKey = SMNDYUVBFMFKNZ-UHFFFAOYSA-N |
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| CASNo_Ref = {{cascite|correct|CAS}} |
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| CASNo_Ref = {{cascite|correct|CAS}} |
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| CASNo = 109-72-8 |
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| CASNo = 88-14-2 |
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| UNII_Ref = {{fdacite|correct|FDA}} |
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| PubChem = 61028 |
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| UNII = P577F6494A |
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}} |
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| PubChem = 6919 |
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| Section2 = {{Chembox Properties |
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}} |
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|C=4|H=9|Li=1 |
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|Section2={{Chembox Properties |
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| Appearance = colorless liquid<br />unstable<br />usually obtained<br />as solution |
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| C=5 | H=4 | O=3 |
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| Density = 0.68 g/cm³, solvent defined |
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| Appearance = White/ Off-White (Beige) Crystalline Powder |
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| Solubility = reacts violently |
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| Density = 0.55 g/cm<sup>3</sup> |
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| Solvent = ] |
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| Solubility = Easily soluble in cold and hot water, 27.1 g/L |
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| SolubleOther = soluble |
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| MeltingPtC = 128 to 132 |
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| Solvent = ] |
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| BoilingPtC = 230 to 232 |
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| SolubleOther = soluble |
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| MeltingPt = -76 °C (<273 K) |
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| pKa = 3.12 at 25 °C |
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}} |
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| BoilingPt = decomposes |
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|Section7={{Chembox Hazards |
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| pKa = >35 (need source) |
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| ExternalSDS = |
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}} |
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| MainHazards = Irritating to eyes, respiratory system and skin. |
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| Section3 = {{Chembox Structure |
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| NFPA-H = 2 |
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| MolShape = tetrameric in solution |
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| NFPA-F = 1 |
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| Dipole = 0 ] |
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| NFPA-R = 0 |
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}} |
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| NFPA-S = |
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| Section7 = {{Chembox Hazards |
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| GHSPictograms = {{GHS07}} |
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| ExternalMSDS = |
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| GHSSignalWord = Warning |
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| MainHazards = inflames in air,<br /> decomposes to<br />corrosive LiOH |
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| HPhrases = {{H-phrases|315|319|335}} |
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}} |
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| PPhrases = {{P-phrases|261|264|271|280|302+352|304+340|305+351+338|312|321|332+313|337+313|362|403+233|405|501}} |
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| Section8 = {{Chembox Related |
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}} |
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| OtherCations = |
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|Section8={{Chembox Related |
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| Function = ] |
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| OtherCompounds = 2-Thiophenecarboxylic acid, <br/>3-Furoic acid, Furfuryl alcohol, <br/>2,5-Furandicarboxylic acid, <br/>Furfurylamine |
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| OtherFunctn = ]<br />]<br />]<br />] |
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}} |
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| OtherCpds = ] |
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] |
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'''''n''-Butyllithium''' (abbreviated '''''n''-BuLi''') is an ]. It is widely used as a ] initiator in the production of ]s such as ] or ]. Also, it is broadly employed as a strong ] (]) in organic synthesis, both industrially and in the laboratory. |
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'''2-Furoic acid''' is an ], consisting of a ] ring and a ] side-group. Along with other furans, its name is derived from the Latin word ''furfur'', meaning bran, from which these compounds were first produced.<ref name="Furan">{{cite book|first=Alexander|last=Senning|title=Elsevier's Dictionary of Chemoetymology|publisher=Elsevier|date=2006|isbn=0-444-52239-5}}</ref> The ] and ]s of furoic acids are known as '''furoates'''. 2-Furoic acid is most widely encountered in food products as a preservative and a flavouring agent, where it imparts a sweet, earthy flavour.<ref name=flavour /> |
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Butyllithium is commercially available as solutions (15%, 25%, 2 M, 2.5 M, 10 M, etc.) in ]s such as ], ]s, and ]s. Solutions in ] and ] can be prepared, but are not stable enough for storage. Annual worldwide production and consumption of butyllithium and other organolithium compounds is estimated at 1800 tonnes.{{Citation needed|date=May 2008}} |
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==History== |
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Although it is a colourless liquid, ''n-''butyllithium is usually encountered as a pale yellow solution in alkanes. Such solutions are stable indefinitely if properly stored,<ref name=Brandsma>{{cite book | author = Brandsma, L.; Verkraijsse, H. D. | title = Preparative Polar Organometallic Chemistry I | publisher = ] | location = Berlin | year = 1987 | isbn = 3-540-16916-4}}</ref> but in practice, they degrade upon aging. Fine white precipitate (]) is deposited and the color changes to orange. |
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The compound was first described by ] in 1780, who obtained it by the dry distillation of ]. For this reason it was initially known as pyromucic acid. This was the first known synthesis of a ] compound, the second being ] in 1821.<ref>{{cite journal| title = Ueber die medicinische und chemische Anwendung und die vortheilhafte Darstellung der Ameisensäure |trans-title = On the medical and chemical application and the profitable preparation of formic acid| pages = 141–146| author = J. W. Döbereiner| volume = 3| issue = 2| year = 1832| journal = Annalen der Pharmacie| doi = 10.1002/jlac.18320030206| url = https://zenodo.org/record/1426896 |language=de }} From p. 141: ''"Ich verbinde mit diese Bitte noch die Bemerkung, … Bittermandelöl riechende Materie enthält, … "'' (I join to this request also the observation that the formic acid which is formed by the simultaneous reaction of sulfuric acid and manganese peroxide with sugar and which contains a volatile material that appears oily in an isolated condition and that smells like a mixture of cassia and bitter almond oil … )</ref><ref name=Stenhouse1>{{cite journal| title = On the Oils Produced by the Action of Sulphuric Acid upon Various Classes of Vegetables. | pages = 939–941| author = John Stenhouse| volume = 5| year = 1843| journal = Abstracts of the Papers Communicated to the Royal Society of London| jstor = 111080| doi=10.1098/rspl.1843.0234| url = https://zenodo.org/record/1432029| doi-access = free}} |
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* See also: {{cite journal |last1=Stenhouse |first1=John |title=On the oils produced by the action of sulphuric acid upon various classes of vegetables |journal=Philosophical Transactions of the Royal Society of London |date=1850 |volume=140 |pages=467–480 |doi=10.1098/rstl.1850.0024 |s2cid=186214485 |doi-access=free }}</ref> |
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Despite this, it was furfural which came to set naming conventions for later furans. |
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==Structure and bonding== |
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==Preparation and synthesis== |
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] (R = CH<sub>2</sub>OH) or ] (R = CHO) to 2-furoic acid by ''Nocardia corallina'']] |
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{{main|Organolithium reagent}} |
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''n''-BuLi exists as a cluster both in the solid state and in a solution. The tendency to aggregate is common for organolithium compounds. The aggregates are held together by delocalized covalent bonds between lithium and the terminal carbon of the butyl chain.<ref>Elschenbroich, C. ”Organometallics” (2006) Wiley-VCH: Weinheim. ISBN 978-3-29390-6</ref> In the case of ''n''-BuLi, the clusters are tetrameric (in ether) or hexameric (in ]). The cluster is a distorted ] structure with Li and ''C''H<sub>2</sub>R groups at alternating vertices. An equivalent description describes the tetramer as a Li<sub>4</sub> ] interpenetrated with a tetrahedron <sub>4</sub>. Bonding within the cluster is related to that used to describe diborane, but more complex since eight atoms are involved. Reflecting its "electron-deficient character," ''n''-butyllithium is highly reactive toward ]s. |
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2-Furoic acid can be synthesized by the oxidation of either ] or ]. This can be achieved either chemically or ]. |
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Due to the large difference between the ] of ] (]) and ] (]), the C-Li bond is highly polarized. The charge separation has been estimated to be 55-95%. For practical purposes, n-BuLi can often be considered to react as the butyl ], ''n''-Bu<sup>−</sup>, and a lithium ], Li<sup>+</sup>. |
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The current industrial route involves the ] of furfural in an aqueous NaOH solution. This is a ] reaction and produces a 1:1 ratio of 2-furoic acid and furfuryl alcohol (a 50% yield of each).<ref name="MariscalMaireles-Torres2016">{{cite journal|last1=Mariscal|first1=R.|last2=Maireles-Torres|first2=P.|last3=Ojeda|first3=M.|last4=Sádaba|first4=I.|last5=López Granados|first5=M.|title=Furfural: a renewable and versatile platform molecule for the synthesis of chemicals and fuels|journal=Energy Environ. Sci.|volume=9|issue=4|year=2016|pages=1144–1189|issn=1754-5692|doi=10.1039/C5EE02666K|url=https://digital.csic.es/bitstream/10261/184700/1/Mariscal_Furfural-A%20renewable_versatile_2016_postprint.pdf|hdl=10261/184700|s2cid=101343477 |hdl-access=free}}</ref> It remains economical because both products have commercial value. The bio-catalytic route involves the microorganism ''] corallina''. This produces 2-furoic acid in higher yields: 98% from 2-furfuryl alcohol and 88% from 2-furfural,<ref>{{cite journal | title = Microbial biocatalytic preparation of 2-furoic acid by oxidation of 2-furfuryl alcohol and 2-furanaldehyde with Nocardia corallina | first = Herminia | last = Pérez | volume = 8 | issue = 10 | year = 2009 | journal = African Journal of Biotechnology}}</ref> but has yet to be commercialised. |
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==Preparation== |
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The standard preparation for ''n''-BuLi is reaction of ] or ] with Li metal:<ref name=Brandsma/> |
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: 2 Li + C<sub>4</sub>H<sub>9</sub>X → C<sub>4</sub>H<sub>9</sub>Li + LiX |
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: where X = Cl, Br |
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The lithium for this reaction contains 1-3% ]. Solvents used for this preparation include ], cyclohexane, and diethyl ether. When BuBr is the precursor, the product is a homogeneous solution, consisting of a mixed cluster containing both LiBr and BuLi, together with a small amount of ]. BuLi forms a weaker complex with LiCl, so that the reaction of BuCl with Li produces a precipitate of ]. |
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==Applications== |
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==Applications and occurrences== |
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], an ] derived from 2-feroic acid,<ref name=Nat2006rev>{{cite journal|last1=Farthing|first1=Michael JG|title=Treatment options for the eradication of intestinal protozoa|journal=Nature Clinical Practice Gastroenterology & Hepatology|date=August 2006|volume=3|issue=8|pages=436–445|doi=10.1038/ncpgasthep0557|pmid=16883348|s2cid=19657328}}</ref> is on the ].<ref name="WHO21st">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 21st list 2019 | year = 2019 | hdl = 10665/325771 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO | hdl-access=free }}</ref>]] |
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Butyllithium is principally valued as an initiator for the anionic ] of ]s, such as ].<ref>Ulrich Wietelmann and Richard J. Bauer “Lithium and Lithium Compounds” in Ullmann's Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. {{DOI|10.1002/14356007.a15_393}}</ref> The reaction is called "carbolithiation": |
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In terms of commercial uses, 2-furoic acid is often used in the production of furoate esters, some of which are drugs and pesticides.<ref>{{cite journal |last1=Zitt |first1=Myron |last2=Kosoglou |first2=Teddy |last3=Hubbell |first3=James |title=Mometasone Furoate Nasal Spray: A Review of Safety and Systemic Effects |journal=Drug Safety |date=2007 |volume=30 |issue=4 |pages=317–326 |doi=10.2165/00002018-200730040-00004|pmid=17408308 |s2cid=42398133 }}</ref> |
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: C<sub>4</sub>H<sub>9</sub>Li + CH<sub>2</sub>=CH-CH=CH<sub>2</sub> → C<sub>4</sub>H<sub>9</sub>-CH<sub>2</sub>-CH=CH-CH<sub>2</sub>Li |
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] can be polymerized stereospecifically in this way. Also of commercially importance is the use of butyllithium for the production of ] polymers. Even ] will insert into BuLi.{{Citation needed|date=September 2009}} |
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==Reactions== |
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===In foods=== |
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It is a flavoring ingredient and achieved a ] (GRAS) status in 1995 by the ] (FEMA). 2-Furoic acid has a distinct odor described as sweet, oily, ], and earthy.<ref name=flavour>{{cite encyclopedia |last=Burdock |encyclopedia=Encyclopedia of Food and Color Additives |isbn=0-8493-9414-7 |first=George |publisher=Bob Stern |title=P–Z indexes |volume=3 |pages=2359 |year=1996 }}</ref> |
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Butyllithium is a strong base (pK<sub>a</sub> ≈ 40), but it is also a powerful ] and ], depending on the other reactants. Furthermore, in addition to being a strong nucleophile, n-BuLi binds to aprotic Lewis bases, such as ethers and tertiary ]s, which partially disaggregate the clusters by binding to the lithium centers. Its use as a strong ] is referred to as ]. Reactions are typically conducted in ] and ], which are good solvents for the resulting organolithium derivatives (see below). |
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2-Furoic acid helps sterilize and ] many foods. It forms in situ from 2-furfural.<ref>{{cite journal | last1 = Hucker | first1 = B. | last2 = Varelis | first2 = P. | year = 2011 | title = Thermal decarboxylation of 2-furoic acid and its implication for the formation of furan in foods | journal = Food Chemistry | volume = 126 | issue = 3| pages = 1512–1513 | doi = 10.1016/j.foodchem.2010.12.017 }}</ref> 2-Furoic acid is also formed during coffee roasting, with up to 205 mg/kg.<ref>{{cite journal |title= A novel UHPLC method for determining the degree of coffee roasting by analysis of furans|journal=Food Chemistry |volume=341|pages=128165 |doi=10.1016/j.foodchem.2020.128165|year=2021|last1=Macheiner |first1=Lukas |last2=Schmidt |first2=Anatol |last3=Karpf |first3=Franz |last4=Mayer |first4=Helmut K. |issue=Pt 1 |pmid=33038777 |s2cid=222280614 }}</ref> |
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===Metalation=== |
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{{main|Organolithium reagent}} |
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One of the most useful chemical properties of ''n''-BuLi is its ability to deprotonate a wide range of weak ]s. ''t''-Butyllithium and ''s''-butyllithium are more basic. ''n''-BuLi can deprotonate (that is, metalate) many types of C-H bonds, especially where the ] is stabilized by electron ] or one or more heteroatoms (non carbon atoms). Examples include acetylenes (''H''-CC-R), methyl sulfides (''H''-CH<sub>2</sub>SR), thioacetals (''H''-CH(SR)<sub>2</sub>, e.g. ]), methylphosphines (''H''-CH<sub>2</sub>PR<sub>2</sub>), ]s, ]s and ] (Fe(''H''-C<sub>5</sub>H<sub>4</sub>)(C<sub>5</sub>H<sub>5</sub>)).<ref>{{cite journal | author = Sanders, R.; Mueller-Westerhoff, U. T. | title = The Lithiation of Ferrocene and Ruthenocene — A Retraction and an Improvement | journal = ] | year = 1996 | volume = 512 | issue = 1-2 | pages = 219–224 | doi=10.1016/0022-328X(95)05914-B}}</ref> In addition to these, it will also deprotonate all more acidic compounds such as alcohols, amines, ]izable carbonyl compounds, and any overtly acidic compounds, to produce alkoxides, amides, enolates and other -ates of lithium, respectively. The stability and ] of the ] resulting from such ] reactions is convenient, but can also be a problem for large-scale reactions because of the volume of a flammable gas produced. |
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===Optic properties=== |
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: LiC<sub>4</sub>H<sub>9</sub> + R-H → C<sub>4</sub>H<sub>10</sub> + R-Li |
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2-Furoic acid crystals are highly transparent in the 200–2000 nm wavelength region, are stable up to 130 °C, and generally have low absorption in the ], visible, and ] ranges.<ref name="uma1">{{cite journal | last1 = Uma | first1 = B. | last2 = Das | first2 = S. Jerome | last3 = Krishnan | first3 = S. | last4 = Boaz | first4 = B. Milton | year = 2011 | title = Growth, optical and thermal studies on organic nonlinear optical crystal: 2-Furoic acid | journal = Physica B: Condensed Matter | volume = 406 | issue = 14| pages = 2834–2839 | doi = 10.1016/j.physb.2011.04.038 | bibcode = 2011PhyB..406.2834U }}</ref> In optical and ] studies, 2-furoic acid crystals may act as ] in the temperature range < 318 K and ] in temperature ranges > 318 K.<ref>{{cite journal|first1=B.|last1=Uma|first2=K. Sakthi|last2=Murugesan|first3=S.|last3=Krishnan|first4=S. Jerome|last4=Das|first5=B. Milton|last5=Boaz|title=Optical and dielectric studies on organic nonlinear optical 2-furoic acid single crystals|journal=Optik|volume=124|issue=17|pages=2754–2757|doi=10.1016/j.ijleo.2012.08.075|year=2013|bibcode=2013Optik.124.2754U}}</ref> |
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==Microbial metabolism== |
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The kinetic basicity of ''n''-BuLi is affected by the solvent or cosolvent. Ligands that complex Li<sup>+</sup> such as ] (THF), ] (TMEDA), ] (HMPA), and 1,4-diazabicyclooctane (]) further polarize the Li-C bond and accelerate the metalation. Such additives can also aid in the isolation of the lithiated product, a famous example of which is dilithioferrocene. |
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2-Furoic acid can be the sole source of carbon and energy for the organism '']''. The organism aerobically degrades the compound. |
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:Fe(C<sub>5</sub>H<sub>5</sub>)<sub>2</sub> + 2 LiC<sub>4</sub>H<sub>9</sub> + 2 TMEDA → 2 C<sub>4</sub>H<sub>10</sub> + Fe(C<sub>5</sub>H<sub>4</sub>Li)<sub>2</sub>(TMEDA)<sub>2</sub> |
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<ref>{{cite journal | title = Ueber das Tetraphenol C<sub>4</sub>H<sub>4</sub>O | trans-title = On tetraphenol C<sub>4</sub>H<sub>4</sub>O | pages = 90–91 | first = H. | last = Limpricht | volume = 3 | issue = 1 | year = 1870 | journal = Berichte der Deutschen Chemischen Gesellschaft | doi =10.1002/cber.18700030129| url = https://zenodo.org/record/1424994 }}</ref> |
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<ref>{{cite journal | title = Molybdenum Involvement in Aerobic Degradation of 2-Furoic Acid by ''Pseudomonas putida'' Ful. | first = KERSTIN | last = KOENIG | volume = 55 | issue = 7 | year = 1988 | journal = Applied and Environmental Microbiology | pmc=202958 | pmid=16347977 | pages=1829–34| doi = 10.1128/aem.55.7.1829-1834.1989 }}</ref> |
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==Hazards== |
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] is a ] produced by treating butyllithium with ]. It is kinetically more reactive than butyllithium and is often used to accomplish difficult ]s. The butoxide anion complexes the lithium and effectively produces butylpotassium, which is more reactive than the corresponding lithium reagent. |
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The LD50 is 100 mg/kg (oral, rats).<ref name=Ull>{{Ullmann|author1=H. E. Hoydonckx|author2=W. M. Van Rhijn|author3=W. Van Rhijn|author4=D. E. De Vos|author5=P. A. Jacobs |title=Furfural and Derivatives|year=2007|doi=10.1002/14356007.a12_119.pub2}}</ref> |
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An example of the use of n-butyllithium as a base is the addition of an amine to methyl carbonate to form a methyl ], where n-butyllithium serves to deprotonate the amine: |
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: n-BuLi + R<sub>2</sub>NH + (MeO)<sub>2</sub>CO → R<sub>2</sub>N-CO<sub>2</sub>Me + LiOMe + BuH |
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===Halogen-lithium exchange=== |
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Butyllithium reacts with some organic bromides and iodides in an exchange reaction to form the corresponding organolithium derivative. The reaction usually fails with organic chlorides and fluorides: |
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: C<sub>4</sub>H<sub>9</sub>Li + RX → C<sub>4</sub>H<sub>9</sub>X + RLi (X = Br, I) |
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This reaction is useful for preparation of several types of RLi compounds, particularly ]lithium and some ]lithium reagents. The utility of this method is significantly limited, however, by the presence in the reaction mixture of n-BuBr or n-BuI, which can react with the RLi reagent formed, and by competing ] reactions, in which n-BuLi serves as a base: |
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: 2 C<sub>4</sub>H<sub>9</sub>Br + RLi → 2 C<sub>4</sub>H<sub>9</sub>R + LiBr |
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: 2 C<sub>4</sub>H<sub>9</sub>Li + R'CH=CHBr → 2 C<sub>4</sub>H<sub>10</sub> + R'C≡CLi + LiBr |
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These side reaction are significantly less important for RI than for RBr, since the iodine-lithium exchange is several orders of magnitude faster than the bromine-lithium exchange. For these reasons, aryl, vinyl and primary alkyl iodides are the preferred substrates, and ] rather than n-BuLi is usually used, since the formed t-BuI is immediately destroyed by the t-BuLi in a dehydrohalogenation reaction (thus requiring 2 equiv of t-BuLi). Alternatively, vinyl lithium reagents can be generated by direct reaction of the vinyl halide (e.g. cyclohexenyl chloride) with lithium or by tin-lithium exchange (see next section).<ref name=Brandsma/> |
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===Transmetalations=== |
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A related family of reactions are the ]s, wherein two organometallic compounds exchange their metals. Many examples of such reactions involve Li exchange with ]: |
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: C<sub>4</sub>H<sub>9</sub>Li + Me<sub>3</sub>SnAr → C<sub>4</sub>H<sub>9</sub>SnMe<sub>3</sub> + LiAr |
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: where Ar is aryl and Me is methyl |
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The tin-lithium exchange reactions have one major advantage over the halogen-lithium exchanges for the preparation of organolithium reagents, in that the product tin compounds (C<sub>4</sub>H<sub>9</sub>SnMe<sub>3</sub> in the example above) are much less reactive towards lithium reagents than are the halide products of the corresponding halogen-lithium exchanges (C<sub>4</sub>H<sub>9</sub>Br or C<sub>4</sub>H<sub>9</sub>Cl). Other ]s and ]s which undergo such exchange reactions are organic compounds of ], ], and ]. |
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===Carbonyl additions=== |
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Organolithium reagents, including ''n''-BuLi are used in synthesis of specific ]s and ]s. One such synthetic pathway is the reaction of an organolithium reagent with disubstituted ]s: |
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: R<sup>1</sup>Li + R<sup>2</sup>CONMe<sub>2</sub> → LiNMe<sub>2</sub> + R<sup>2</sup>C(O)R<sup>1</sup> |
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===Degradation of THF=== |
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THF is deprotonated by butyllithium, especially in the presence of ], by loss of one of four protons adjacent to oxygen. This process, which consumes butyllithium to generate butane, induces a reverse ] to give enolate of ] and ]. Therefore, reactions of BuLi in THF are typically conducted at low temperatures, such as –78 °C, as is conveniently produced by a ] of ]/acetone. Higher temperatures (-25 °C or even -15 °C) are also used. |
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===Thermal decomposition=== |
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When heated, ''n''-BuLi, analogously to other alkyllithium reagents with "β-hydrogens", undergoes ] to produce ] and LiH: |
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: C<sub>4</sub>H<sub>9</sub>Li → LiH + CH<sub>3</sub>CH<sub>2</sub>CH=CH<sub>2</sub> |
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==Safety== |
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Alkyl-lithium compounds are stored under inert gas to prevent loss of activity and for reasons of safety. ''n''-BuLi reacts violently with water: |
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: C<sub>4</sub>H<sub>9</sub>Li + H<sub>2</sub>O → C<sub>4</sub>H<sub>10</sub> + ] |
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BuLi also reacts with CO<sub>2</sub> to give lithium pentanoate: |
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: C<sub>4</sub>H<sub>9</sub>Li + CO<sub>2</sub> → C<sub>4</sub>H<sub>9</sub>CO<sub>2</sub>Li |
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==References== |
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==References== |
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Line 91: |
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==Further reading== |
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==Further reading== |
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* {{Greenwood&Earnshaw2nd}} |
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* |
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* {{cite web|website=Sciencelab.com|date=October 9, 2005|title=2-Furoic Acid |url=http://www.sciencelab.com/msds.php?msdsId=9924109|access-date=March 15, 2013|archive-url=https://web.archive.org/web/20121017150124/http://www.sciencelab.com/msds.php?msdsId=9924109|archive-date=October 17, 2012|url-status=dead}} |
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* Weissenbacher, Anderson, Ishikawa, ''Organometallics'', July 1998, p681.7002, Chemicals Economics Handbook SRI International |
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* |
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* Ovaska, T. V. ''e-EROS ]'' "n-butyllithium." Wiley and sons. 2006. {{doi|10.1002/047084289X.rb395}} |
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* Greenwood, N. N.; Earnshaw, A. ''Chemistry of the Elements'', 2nd ed. 1997: Butterworth-Heinemann, Boston. |
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{{DEFAULTSORT:Butyllithium, N-}} |
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{{DEFAULTSORT:Furoic acid, 2-}} |
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