仲丁基锂

仲丁基锂,化学式 CH
3
CHLiCH
2
CH
3
,简称sec-BuLi或s-BuLi,是一种有机锂化合物,为正丁基锂叔丁基锂异构体。这种有手性有机锂试剂有机合成中仲丁基碳阴离子的来源。[2]

仲丁基锂
IUPAC名
sec-Butyllithium
系统名
Butan-2-yllithium
英文名
识别
CAS号 598-30-1  checkY
PubChem 102446
ChemSpider 10254345
SMILES
 
  • [Li]C(C)CC
InChI
 
  • 1/C4H9.Li/c1-3-4-2;/h3H,4H2,1-2H3;/rC4H9Li/c1-3-4(2)5/h4H,3H2,1-2H3
InChIKey VATDYQWILMGLEW-MHILWDCKAX
Beilstein 3587206
EINECS 209-927-7
性质
化学式 C4H9Li
摩尔质量 64.06 g·mol−1
外观 无色液体[1]
沸点 90℃ (0.05 Torr)[2]
溶解性 可溶于环己烷[3]
pKa 51
相关物质
相关化学品 正丁基锂
叔丁基锂
若非注明,所有数据均出自标准状态(25 ℃,100 kPa)下。

制备

仲丁基锂可以由2-氯丁烷单质反应而成。[4]

Herstellung von sec.-Butyllithium

性质

物理性质

仲丁基锂是一种无色粘稠液体。[5]通过质谱法,发现了仲丁基锂的四聚体结构。[6]环己烷环戊烷等非极性溶剂中,它就是以四聚体存在的。[5][7][8]在 −41 °C的环戊烷溶液中使用6Li-NMR,可以探测到六聚体。[8]在具有配体性质的溶剂(如四氢呋喃)里,二聚体和单体之间存在平衡。[9]

化学性质

相较于正丁基锂,仲丁基锂在室温下和乙醚THF的反应更快。它会分解成氢化锂和各种丁烯(1-丁烯、顺式和反式的2-丁烯)[10][11]

仲丁基锂的分解

仲丁基锂可自燃[1],并产生红色的火焰

用处

碳-锂键是高度极性的,所以其中的原子的亲核性和碱性很强。位阻更多的仲丁基锂的碱性比正丁基锂还强。这些性质可用于各种用途。举个例子,当有机化合物的C-H键酸性很弱,正丁基锂不能使用时,可以使用仲丁基锂。它也用于催化异戊二烯丁二烯苯乙烯聚合反应。[1]

参考资料

  1. Entry on Butyllithium. at: Römpp Online. Georg Thieme Verlag, retrieved 2013-12-06.
  2. Ovaska, T. V. "s-Butyllithium" in Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons: New York. doi:10.1002/047084289X.rb397.
  3. 来源:Sigma-Aldrich Co., product no. 195596 (2011-04-23查阅).
  4. H. Gilman, F. W. Moore, O. Baine: Secondary and Tertiary Alkyllithium Compounds and Some Interconversion Reactions with Them. In: J. Am. Chem. Soc. 63, 1941, S. 2479–2482, doi:10.1021/ja01854a046.
  5. U. Wietelmann, R. J. Bauer: Lithium and Lithium Compounds. In: Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH Verlag, Weinheim 2005, doi:10.1002/14356007.a15_393
  6. D. Plavsic, D. Srzic, L. Klasinc: Mass spectrometric investigations of alkyllithium compounds in the gas phase. In: J. Phys. Chem. 90, 1986, S. 2075–2080, doi:10.1021/j100401a020.
  7. S. Bywater, D. J. Worsfold: Alkyllithium anionic polymerization initiators in hydrocarbon solvents. In: J. Organomet. Chem. 10, 1967, S. 1–6.
  8. G. Fraenkel, M. Henrichs, M. Hewitt, B. M. Su: Structure and dynamic behavior of a chiral alkyllithium compound: 13C and 6Li NMR of sec-butyllithium. In: J. Am. Chem. Soc. 106, 1984, S. 255–256.
  9. W. Bauer, W. R. Winchester, P. von Schleyer: Monomeric organolithium compounds in tetrahydrofuran: tert-butyllithium, sec-butyllithium, supermesityllithium, mesityllithium, and phenyllithium. Carbon-lithium coupling constants and the nature of carbon-lithium bonding. In: Organometallics. 6, 1987, S. 2371–2379, doi:10.1021/om00154a017.
  10. W. H. Glaze, J. Lin, E. G. Felton: The Thermal Decomposition of sec.-Butyllithium. In: J. Org. Chem. 30, 1965, S. 1258–1259, doi:10.1021/jo01015a514.
  11. W. H. Glaze, J. Lin, E. G. Felton: The Pyrolysis of Unsolvated Alkyllithium Compounds. In: J. Org. Chem. 31, 1966, S. 2643–2645, doi:10.1021/jo01346a044.

扩展阅读

  • Heinz G. O. Becker u. a.: Organikum. 21. Auflage. Wiley-VCH, Weinheim 2001, ISBN 3-527-29985-8.
  • Christoph Elschenbroich: Organometallchemie. 5. Auflage. Teubner, Wiesbaden 2005, ISBN 3-519-53501-7.
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