仲丁基锂
仲丁基锂 | |
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IUPAC名 sec-Butyllithium | |
系统名 Butan-2-yllithium | |
英文名 | sec-Butyllithium |
识别 | |
CAS号 | 598-30-1 ![]() |
PubChem | 102446 |
ChemSpider | 10254345 |
SMILES |
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InChI |
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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。 |
仲丁基锂,化学式 CH
3CHLiCH
2CH
3,简称sec-BuLi或s-BuLi,是一种有机锂化合物,为正丁基锂和叔丁基锂的异构体。这种有手性的有机锂试剂是有机合成中仲丁基碳阴离子的来源。[2]
制备
性质
![](http://images.weserv.nl/?url=//upload.wikimedia.org/wikipedia/commons/thumb/5/51/Sec-butyllithium-2D-skeletal.png/100px-Sec-butyllithium-2D-skeletal.png)
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]在苯、环己烷和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]
用处
碳-锂键是高度极性的,所以其中的碳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、丁二烯和苯乙烯的聚合反应。[1]
参考资料
- ^ 1.0 1.1 1.2 Entry on Butyllithium. at: Römpp Online. Georg Thieme Verlag, retrieved 2013-12-06.
- ^ 2.0 2.1 Ovaska, T. V. "s-Butyllithium" in Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons: New York. doi:10.1002/047084289X.rb397.
- ^ 来源:Sigma-Aldrich Co., product no. 195596 (2011-04-23查阅).
- ^ 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.
- ^ 5.0 5.1 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
- ^ 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.
- ^ S. Bywater, D. J. Worsfold: Alkyllithium anionic polymerization initiators in hydrocarbon solvents. In: J. Organomet. Chem. 10, 1967, S. 1–6.
- ^ 8.0 8.1 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.
- ^ 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.
- ^ 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.
- ^ 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.
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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.