甲硫醚硼烷

甲硫醚硼烷
別名	BMS, Borane-dimethyl sulfide
識別
CAS號	13292-87-0
PubChem	12423031
SMILES	[BH3-][S+](C)C;
性質
化學式	(CH3)2SBH3
摩爾質量	75.96 g·mol⁻¹
外觀	無色液體
密度	0.801 g/mL
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

甲硫醚硼烷（BMS）是絡合硼烷試劑，用於硼氫化反應和還原反應，比四氫呋喃硼烷等硼烷試劑穩定和溶解度高，^[1]市售濃度比四氫呋喃硼烷（10摩）高得多，亦不需可能會導致副反應的硼氫化鈉作穩定劑；^[2]相反，四氫呋喃硼烷需要硼氫化鈉來抑制THF還原四氫呋喃硼烷硼烷為硼酸三丁酯。^[2]甲硫醚硼烷可溶於多數非質子溶劑。

合成和結構

雖然通常不會在實驗室合成，但可以甲硫醚吸收乙硼烷製成：^[3]

B₂H₆＋2SMe₂　→　2Me₂SBH₃

它可以燈泡到燈泡真空轉移（bulb to bulb vacuum transfer）來淨化。雖然其結構尚未以晶體學確定，但以X光晶體學檢驗甲硫醚五氟苯硼烷（Me₂SBH₂C₆F₅），^[4]硼中心構型為四面體。

反應

硼氫化反應

甲硫醚硼烷易用，常用於硼氫化反應，反應時就地解離，釋出乙硼烷，乙硼烷迅速加入不飽和鍵。所得有機硼烷化合物是有機合成的有用中間體。硼烷以反馬氏方式加到烯烴，並將炔烴轉為順烯。

還原

甲硫醚硼烷可還原多種官能團，醛、酮、環氧化物、酯和羧酸還原為相應的醇；內酯還原為二醇；腈還原為胺，但不會還原酰氯和硝基。

甲硫醚硼烷是高利－伊津野還原常用的本體還原劑。甲硫醚配體抑制硼烷的活性。以計量還原劑的手性惡唑硼烷催化劑的氮激活允許不對稱控制試劑。（按：Activation by the nitrogen of the chiral oxazoborolidine catalyst of the stoichiometric reducing agent allows for asymmetric control of the reagent.這句原文有點怪）甲硫醚硼烷的對映體選擇度通常不比四氫呋喃硼烷顯著，但在有水有氧環境較穩定，是首選還原劑。^[5]

安全

甲硫醚硼烷可燃，與水反應產生易燃氣體，氣味難聞。^[6]

參考資料

^ Hutchins, Robert O.; Cistone, Frank. Utility and Applications of Borane Dimethylsulfide in Organic Synthesis. A Review. Organic Preparations and Procedures International. 1981, 13 (3–4): 225. doi:10.1080/00304948109356130.
^ ^2.0 ^2.1 Kollonitisch, J. Reductive Ring Cleavage of Tetrahydrofurans by Diborane. J. Am. Chem. Soc. 1961, 83 (6): 1515. doi:10.1021/ja01467a056.
^ Braun, L. M.; Braun, R. A.; Crissman, R.; Opperman, M.; Adams, R. M. Dimethyl Sulfide-Borane. A Convenient Hydroborating Reagent. J. Org. Chem. 1971, 36 (16): 2388–2389. doi:10.1021/jo00815a047.
^ Fuller, Anna-Marie; Hughes, David L.; Lancaster, Simon J.; White, Callum M. Synthesis and Structure of the Dimethyl Sulfide Adducts of Mono- and Bis(pentafluorophenyl)borane. Organometallics. 2010, 29 (9): 2194. doi:10.1021/om100152v.
^ Corey, E.J.; Helal, C. J. Reduction of Carbonyl Compounds with Chiral Oxazoborolidine Catalysts: A New Paradigm for Enantioselective Catalysis and a Powerful New Synthetic Method. Angew. Chem. Int. Ed. 1998, 37 (15): 1986–2012. doi:10.1002/(SICI)1521-3773(19980817)37:15<1986::AID-ANIE1986>3.0.CO;2-Z.
^ Sigma-Aldrich Material Safety Data Sheet. www.sigmaaldrich.com/. [29 November 2014]. （原始內容存檔於2018-01-21）.

[1] Hutchins, Robert O.; Cistone, Frank. Utility and Applications of Borane Dimethylsulfide in Organic Synthesis. A Review. Organic Preparations and Procedures International. 1981, 13 (3–4): 225. doi:10.1080/00304948109356130.

[Kollonitisch_1961-2] 2.0 ^2.1 Kollonitisch, J. Reductive Ring Cleavage of Tetrahydrofurans by Diborane. J. Am. Chem. Soc. 1961, 83 (6): 1515. doi:10.1021/ja01467a056.

[3] Braun, L. M.; Braun, R. A.; Crissman, R.; Opperman, M.; Adams, R. M. Dimethyl Sulfide-Borane. A Convenient Hydroborating Reagent. J. Org. Chem. 1971, 36 (16): 2388–2389. doi:10.1021/jo00815a047.

[4] Fuller, Anna-Marie; Hughes, David L.; Lancaster, Simon J.; White, Callum M. Synthesis and Structure of the Dimethyl Sulfide Adducts of Mono- and Bis(pentafluorophenyl)borane. Organometallics. 2010, 29 (9): 2194. doi:10.1021/om100152v.

[5] Corey, E.J.; Helal, C. J. Reduction of Carbonyl Compounds with Chiral Oxazoborolidine Catalysts: A New Paradigm for Enantioselective Catalysis and a Powerful New Synthetic Method. Angew. Chem. Int. Ed. 1998, 37 (15): 1986–2012. doi:10.1002/(SICI)1521-3773(19980817)37:15<1986::AID-ANIE1986>3.0.CO;2-Z.

[6] Sigma-Aldrich Material Safety Data Sheet. www.sigmaaldrich.com/. [29 November 2014]. （原始內容存檔於2018-01-21）.

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