Borane–tetrahydrofuran

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Borane–tetrahydrofuran
Bh3-thf-complex.png
Borane-THF-adduct-3D-balls.png
Identifiers
3D model (JSmol)
EC Number 237-881-8
UNII
Properties
C4H11BO
Molar mass 85.94 g·mol−1
Appearance White solid
Melting point 66 °C (151 °F; 339 K)
Hazards
GHS pictograms The flame pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The corrosion pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H225, H260, H302, H315, H318, H319, H335
P210, P223, P231+232, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+312, P302+352, P303+361+353, P304+340, P305+351+338, P310, P312, P321, P330, P332+313, P335+334, P337+313
Flash point −17 °C (1 °F; 256 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Borane–tetrahydrofuran is a dipolar bond complex composed of borane and tetrahydrofuran (THF). These solutions are used for reductions and hydroboration, reactions that are useful in synthesis of organic compounds.[1]

Preparation and uses[edit]

The complex is commercially available but can also be generated by the dissolution of diborane in THF. A practical route to this is the oxidation of sodium borohydride with iodine in THF.[2]

The complex can reduce carboxylic acids to alcohols and is a common route for the reduction of amino acids to amino alcohols[3] (e.g. valinol). It adds across alkenes to give organoboron compounds that are useful intermediates,[4] the following organoboron reagents are prepared from borane-THF: 9-borabicyclo[3.3.1]nonane, Alpine borane, diisopinocampheylborane. It is also used as a source of borane (BH3) for the formation of adducts.[5]

Safety[edit]

The solution is highly sensitive to air, requiring the use of air-free techniques.[1]

See also[edit]

References[edit]

  1. ^ a b Marek Zaidlewicz, Herbert C. Brown, Santhosh F. Neelamkavil, "Borane–Tetrahydrofuran" Encyclopedia of Reagents for Organic Synthesis, 2008 John Wiley & Sons. doi:10.1002/047084289X.rb241.pub2
  2. ^ Kanth, J. V. Bhaskar; Periasamy, Mariappan (1 September 1991). "Selective reduction of carboxylic acids into alcohols using sodium borohydride and iodine". The Journal of Organic Chemistry. 56 (20): 5964–5965. doi:10.1021/jo00020a052. 
  3. ^ McKennon, Marc J.; Meyers, A. I.; Drauz, Karlheinz; Schwarm, Michael (June 1993). "A convenient reduction of amino acids and their derivatives". The Journal of Organic Chemistry. 58 (13): 3568–3571. doi:10.1021/jo00065a020. 
  4. ^ George W. Kabalka, John T. Maddox, Timothy Shoup, and Karla R. Bowers "A Simple And Convenient Method For The Oxidation Of Organoboranes Using Sodium Perborate: (+)-isopinocampheol" Org. Synth. 1996, vol. 73, p. 116. doi:10.15227/orgsyn.073.0116
  5. ^ Karen V. L. Crépy and Tsuneo Imamoto "Preparation Of (S,S)-1,2-Bis-(tert-butylmethylphosphino)ethane ((s,s)-t-Bu-bisp*) As A Rhodium Complex" Org. Synth. 2005, vol. 82, 22. doi:10.15227/orgsyn.082.0022