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{{chembox |
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{{Chembox |
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|Watchedfields = changed |
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| verifiedrevid = 396342334 |
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|verifiedrevid = 435111382 |
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| ImageFile = DIBAH.png |
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|ImageFile = DIBAL-H-dimer.svg |
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| ImageSize = 300px |
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| ImageFile1 = DIBAL-3D-balls.png |
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|ImageSize = 250px |
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|ImageFile1 = DIBAL-3D-balls.png |
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| IUPACName = Diisobutylaluminum hydride |
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|IUPACName = Diisobutylaluminium hydride |
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| OtherNames = DIBAH; DIBAL; DiBAlH; DIBAL-H; DIBALH |
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|OtherNames = DIBAH; DIBAL; DiBAlH; DIBAL-H; DIBALH |
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| Section1 = {{Chembox Identifiers |
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|Section1={{Chembox Identifiers |
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| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}} |
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| ChemSpiderID = 10430352 |
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|ChemSpiderID = 10430352 |
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| InChI = 1/2C4H9.Al.H/c2*1-4(2)3;;/h2*4H,1H2,2-3H3;;/rC8H19Al/c1-7(2)5-9-6-8(3)4/h7-9H,5-6H2,1-4H3 |
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|InChI = 1/2C4H9.Al.H/c2*1-4(2)3;;/h2*4H,1H2,2-3H3;;/rC8H19Al/c1-7(2)5-9-6-8(3)4/h7-9H,5-6H2,1-4H3 |
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| InChIKey = AZWXAPCAJCYGIA-DFAADSFOAF |
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|InChIKey = AZWXAPCAJCYGIA-DFAADSFOAF |
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| StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
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|StdInChI_Ref = {{stdinchicite|correct|chemspider}} |
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| StdInChI = 1S/2C4H9.Al.H/c2*1-4(2)3;;/h2*4H,1H2,2-3H3;; |
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|StdInChI = 1S/2C4H9.Al.H/c2*1-4(2)3;;/h2*4H,1H2,2-3H3;; |
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| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
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|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}} |
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| StdInChIKey = AZWXAPCAJCYGIA-UHFFFAOYSA-N |
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|StdInChIKey = AZWXAPCAJCYGIA-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 = 1191-15-7 |
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|CASNo = 1191-15-7 |
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| PubChem = |
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|PubChem = 16682954 |
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|PubChem_Comment = (monomer) |
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| SMILES = CC(C)CCC(C)C |
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|PubChem1 = 131737379 |
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|PubChem1_Comment = (dimer) |
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|EC_number = 214-729-9 |
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|UNII = H2EJ47H11A |
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|SMILES = CC(C)CCC(C)C |
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| Section2 = {{Chembox Properties |
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|Section2={{Chembox Properties |
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| Formula = C<sub>16</sub>H<sub>38</sub>Al<sub>2</sub> (dimer) |
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|Formula = C<sub>8</sub>H<sub>19</sub>Al (monomer)<br>C<sub>16</sub>H<sub>38</sub>Al<sub>2</sub> (dimer) |
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| MolarMass = 142.22 (monomer) |
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|MolarMass = 142.22 g/mol (monomer)<br>284.44 g/mol (dimer) |
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| Appearance = colorless liquid |
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|Appearance = Colorless liquid |
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| Density = 0.798 g/cm<sup>3</sup> |
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|Density = 0.798 g/cm<sup>3</sup> |
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|MeltingPtC = -80 |
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| MeltingPt = –18 °C |
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|BoilingPtC = 116 to 118 |
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| BoilingPt = 116–118 °C/1 mmHg |
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|BoilingPt_notes = at 1 mmHg |
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| Solubility = hydrocarbon solvents |
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|Solubility = Reacts with water |
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}} |
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|SolubleOther = Soluble in hydrocarbons, THF, and ether |
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| Section3 = {{Chembox Hazards |
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| MainHazards = ignites in air |
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| FlashPt = |
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| Autoignition = |
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|Section3={{Chembox Hazards |
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'''Diisobutylaluminium hydride''', DIBAL, DIBAL-H or DIBAH, is a ] with the ] (''i''-Bu<sub>2</sub>AlH)<sub>2</sub>, where ''i''-Bu represents ] (-CH<sub>2</sub>CH(CH<sub>3</sub>)<sub>2</sub>). This ] was investigated originally as a ] for the ] of ]s.<ref>{{cite journal | author = ], H. Martin and F. Krupp | title = Metallorganische Verbindungen, XXVII Aluminiumtrialkyle und Dialkyl-Aluminiumhydride Aus Aluminiumisobutyl-Verbindungen | year = 1960 | journal = ] | volume = 629 | issue = 1 | pages = 14–19 | doi = 10.1002/jlac.19606290103}}</ref> |
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|MainHazards = ignites in air |
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|GHSPictograms = {{GHS flame}}{{GHS corrosion}} |
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|GHSSignalWord = Danger |
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|HPhrases = {{H-phrases|220|225|250|260|314}} |
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|PPhrases = {{P-phrases|210|222|223|231+232|233|240|241|242|243|260|264|280|301+330+331|302+334|303+361+353|304+340|305+351+338|310|321|335+334|363|370+378|377|381|402+404|403|403+235|405|422|501}} |
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'''Diisobutylaluminium hydride''' ('''DIBALH''', '''DIBAL''', '''DIBAL-H''' or '''DIBAH''') is a ] with the ] (''i''-Bu<sub>2</sub>AlH)<sub>2</sub>, where ''i''-Bu represents ] (-CH<sub>2</sub>CH(CH<sub>3</sub>)<sub>2</sub>). This ] is a reagent in organic synthesis.<ref name=Galatsis/> |
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==Properties== |
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==Properties== |
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Like most organoaluminum compounds, the compound’s structure is probably more than that suggested by its ]. A variety of techniques, not including ], suggest that the compound exists as a ] and a trimer, consisting of tetrahedral aluminium centers sharing bridging ] ]s.<ref>{{cite journal | author = Mark F. Self, William T. Pennington and Gregory H. Robinson | title = Reaction of diisobutylaluminum hydride with a macrocyclic tetradentate secondary amine. Synthesis and molecular structure of <sub>2</sub><sub>2</sub>: evidence of an unusual disproportionation of (iso-Bu)2AlH | journal = ] | year = 1990 | volume = 175 | pages = 151–153 | doi = 10.1016/S0020-1693(00)84819-7 | issue = 2}}</ref> Hydrides are small and, for aluminium derivatives, are highly ], thus they bridge in preference to the ] groups. |
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Like most organoaluminum compounds, the compound's structure is most probably more than that suggested by its ]. A variety of techniques, not including ], suggest that the compound exists as a ] and a trimer, consisting of tetrahedral aluminium centers sharing bridging ] ]s.<ref>{{cite journal |author1=Self, M. F. |author2=Pennington, W. T. |author3=Robinson, G. H. |title=Reaction of Diisobutylaluminum Hydride with a Macrocyclic Tetradentate Secondary Amine. Synthesis and Molecular Structure of <sub>2</sub><sub>2</sub>: Evidence of an Unusual Disproportionation of (iso-Bu)<sub>2</sub>AlH |journal=] |year=1990 |volume=175 |issue=2 |pages=151–153 |doi=10.1016/S0020-1693(00)84819-7}}</ref> Hydrides are small and, for aluminium derivatives, are highly ], thus they bridge in preference to the ] groups. |
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DIBAH can be prepared by heating triisobutylaluminium (itself a dimer) to induce ]:<ref>Eisch, J. J. Organometallic Syntheses Volume 2, Academic Press: New York, 1981. ISBN 0-12-234950-4.</ref> |
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DIBAL can be prepared by heating ] (itself a dimer) to induce ]:<ref>{{cite book |author=Eisch, J. J. |title=Organometallic Syntheses |year=1981 |volume=2 |publisher=Academic Press |location=New York |isbn=0-12-234950-4 |url=https://archive.org/details/nontransitionmet0002eisc |url-access=registration}}</ref> |
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:(''i''-Bu<sub>3</sub>Al)<sub>2</sub> → (''i''-Bu<sub>2</sub>AlH)<sub>2</sub> + 2 ]</sub> |
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:(''i''-Bu<sub>3</sub>Al)<sub>2</sub> → (''i''-Bu<sub>2</sub>AlH)<sub>2</sub> + 2 ] |
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Although DIBAH can be purchased commercially as a colorless liquid, it is more commonly purchased and dispensed as a solution in organic solvents such as ]. |
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Although DIBAL can be purchased commercially as a colorless liquid, it is more commonly purchased and dispensed as a solution in an organic solvent such as ] or ]. |
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==Use in organic synthesis== |
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==Use in organic synthesis== |
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DIBAH is useful in ] for a variety of reductions, including converting ]s and ]s to ]s. DIBAH efficiently reduces α-β unsaturated esters to the corresponding allylic alcohol.<ref>Galatsis, P. “Diisobutylaluminum Hydride” in Encyclopedia of Reagents for Organic Synthesis John Wiley & Sons: New York, 2001. {{doi|10.1002/047084289X.rd245}}</ref> By contrast, ] reduces esters and ]s to primary ]s, and ]s to primary ]s . DIBAH reacts slowly with electron-poor compounds, and more quickly with electron-rich compounds. Thus, it is an ] reducing agent whereas LiAlH<sub>4</sub> can be thought of as a ] reducing agent. |
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DIBAL reacts slowly with electron-poor compounds and more quickly with electron-rich compounds. Thus, it is an ] reducing agent whereas LiAlH<sub>4</sub> can be thought of as a ] reducing agent. |
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DIBAL is useful in ] for a variety of reductions, including converting ]s, their derivatives, and ]s to ]s. DIBAL efficiently reduces α-β unsaturated esters to the corresponding allylic alcohol.<ref name=Galatsis>{{cite book |chapter=Diisobutylaluminum Hydride |author=Galatsis, P. |title=Encyclopedia of Reagents for Organic Synthesis |publisher=John Wiley & Sons |location=New York |year=2001 |isbn=0471936235 |doi=10.1002/047084289X.rd245}}</ref> By contrast, ] reduces esters and ]s to primary ], and ]s to primary ]s . Similarly, DIBAL reduces ]s to ]s (the equivalent of an aldehyde).<ref>{{cite journal |doi=10.15227/orgsyn.100.0304 |title=Synthesis of a Furoindoline Scaffold via an Interrupted Fischer Indolization |date=2023 |last1=m. Scherer |first1=Georgia |first2=Jordan|last2=Gonzalez|first3=Laura G.|last3=Wonilowicz|first4=Neil K. |last4=Garg|journal=Organic Syntheses |volume=100 |pages=304–326 }}</ref> |
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Although DIBAL reliably reduces nitriles to aldehydes, the reduction of esters to aldehydes is infamous for often producing large quantities of alcohols. Nevertheless, it is possible to avoid these unwanted byproducts through careful control of the reaction conditions using continuous ].<ref>{{cite journal |last1=Webb |first1=Damien |last2=Jamison |first2=Timothy F. |date=2012-01-20 |title=Diisobutylaluminum Hydride Reductions Revitalized: A Fast, Robust, and Selective Continuous Flow System for Aldehyde Synthesis |journal=Organic Letters |volume=14 |issue=2 |pages=568–571 |issn=1523-7060 |pmid=22206502 |doi=10.1021/ol2031872 |hdl=1721.1/76286 |hdl-access=free}}</ref> |
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DIBALH was investigated originally as a ] for the ] of ]s.<ref>{{cite journal |author1=Ziegler, K. |authorlink1=Karl Ziegler |author2=Martin, H. |author3=Krupp, F. |title=Metallorganische Verbindungen, XXVII Aluminiumtrialkyle und Dialkyl-Aluminiumhydride aus Aluminiumisobutyl-Verbindungen |journal=] |year=1960 |volume=629 |issue=1 |pages=14–19 |doi=10.1002/jlac.19606290103}}</ref> |
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==Safety== |
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==Safety== |
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DIBAL, like most alkylaluminium compounds, reacts violently with air and water, potentially leading to explosion.<ref name=":0">{{cite web |last=Thermo Fisher Scientific |first=Regulatory Affairs |date=January 3, 2005 |title=Safety Data Sheet Diisobutylaluminum hydride |website=Thermo Fisher Scientific |url=https://www.fishersci.com/store/msds?partNumber=AC183791000&productDescription=DIISOBUTYLALUMINIUM+HYDRIDE&vendorId=VN00032119&countryCode=US&language=en |access-date=October 9, 2023}}</ref> |
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DIBAH, like most alkylaluminium compounds, reacts violently with air and water, potentially leading to fires. |
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==References== |
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==References== |
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{{Reflist}} |
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<references/> |
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==External links== |
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==External links== |
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*{{cite journal |author=Stockman, R. |title=Dibal reduction of an amino acid derived methyl ester; Garner's Aldehyde |year=2001 |journal=ChemSpider Synthetic Pages |id=SyntheticPage 161 |doi=10.1039/SP161 |url=https://cssp.chemspider.com/161}} |
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*{{cite web |title=Oxidation and Reduction Reactions in Organic Chemistry |url=https://s10.lite.msu.edu/res/msu/botonl/b_online/library/newton/Chy251_253/Lectures/OxidtionReduction/OxiationReduction.html |url-status=live|archive-url=https://web.archive.org/web/20110611104855/http://www.usm.maine.edu/~newton/Chy251_253/Lectures/OxidtionReduction/OxiationReduction.html |archive-date=2011-06-11}} |
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*{{cite web |title=Diisobutyl Aluminum hydride (DIBAL-H) and Other Isobutyl Aluminum Alkyls (DIBAL-BOT, TIBAL) as Specialty Organic Synthesis Reagents |publisher=Akzo-Nobel |url=http://www.akzonobel.com/polymer/system/images/AkzoNobel_Diisobutylaluminum_hydride_ma_row_eng_tb_tcm96-16226.pdf |access-date=2011-02-23 |url-status=dead |archive-url=https://web.archive.org/web/20110408211849/http://www.akzonobel.com/polymer/system/images/AkzoNobel_Diisobutylaluminum_hydride_ma_row_eng_tb_tcm96-16226.pdf |archive-date=2011-04-08}} |
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