仲丁基鋰

仲丁基鋰
	IUPAC名; sec-Butyllithium
	系統名; Butan-2-yllithium
英文名	sec-Butyllithium
識別
CAS號	598-30-1
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
性質
化學式	C4H9Li
摩爾質量	64.06 g·mol−1
外觀	無色液體
沸點	90℃ (0.05 Torr)
溶解性	可溶於環己烷
pKa	51
相關物質
相關化學品	正丁基鋰; 叔丁基鋰
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

仲丁基鋰，化學式 CH
3CHLiCH
2CH
3，簡稱sec-BuLi或s-BuLi，是一種有機鋰化合物，為正丁基鋰和叔丁基鋰的異構體。這種有手性的有機鋰試劑是有機合成中仲丁基碳陰離子的來源。^[2]

製備[編輯]

仲丁基鋰可以由2-氯丁烷和單質鋰反應而成。^[4]

性質[編輯]

物理性質[編輯]

仲丁基鋰是一種無色粘稠液體。^[5]通過質譜法，發現了仲丁基鋰的四聚體結構。^[6]在苯、環己烷和環戊烷等非極性溶劑中，它就是以四聚體存在的。^[5]^[7]^[8]在 −41 °C的環戊烷溶液中使用⁶Li-NMR，可以探測到六聚體。^[8]在具有配體性質的溶劑（如四氫呋喃）里，二聚體和單體之間存在平衡。^[9]

化學性質[編輯]

相較於正丁基鋰，仲丁基鋰在室溫下和乙醚、THF的反應更快。它會分解成氫化鋰和各種丁烯（1-丁烯、順式和反式的2-丁烯）^[10]^[11]

仲丁基鋰可自燃^[1]，並產生紅色的火焰。

用處[編輯]

碳-鋰鍵是高度極性的，所以其中的碳原子的親核性和鹼性很強。位阻更多的仲丁基鋰的鹼性比正丁基鋰還強。這些性質可用於各種用途。舉個例子，當有機化合物的C-H鍵酸性（德語：C-H-Acidität）很弱，正丁基鋰不能使用時，可以使用仲丁基鋰。它也用於催化異戊二烯、丁二烯和苯乙烯的聚合反應。^[1]

參考資料[編輯]

^ ^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.
^ 來源：Sigma-Aldrich Co., product no. 195596 （2011-04-23查閱）.
^ 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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擴展閱讀[編輯]

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.

[roempp-1] 1.0 ^1.1 ^1.2 Entry on Butyllithium. at: Römpp Online. Georg Thieme Verlag, retrieved 2013-12-06.

[Ovaska-2] 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.

[Sigma-3] 來源：Sigma-Aldrich Co., product no. 195596 （2011-04-23查閱）.

[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.

[Ullmann-5] 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

[Plavsic-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.

[Fraenkel-8] 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.

[Bauer-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.

[Glaze-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.

[Glaze2-11] 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.

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