9-Borabicyclononane

The correct title of this article is 9-Borabicyclo[3.3.1]nonane. The substitution or omission of any < > [ ] { } is due to technical restrictions.

9-Borabicyclo[3.3.1]nonane IUPAC name 9-Borabicyclo[3.3.1]nonane Other names Borabicyclononane Identifiers Abbreviations 9-BBN InChI InChI=1/C8H15B/c1-3-7-5-2-6-8(4-1)9-7/h7-9H,1-6H2 InChIKey FEJUGLKDZJDVFY-UHFFFAOYAE Standard InChI InChI=1S/C8H15B/c1-3-7-5-2-6-8(4-1)9-7/h7-9H,1-6H2 Standard InChIKey FEJUGLKDZJDVFY-UHFFFAOYSA-N CAS number [280-64-8] EC number 206-000-9 ChemSpider 71299 SMILES   C1(B2)CCCC2CCC1 Properties Chemical formula C8H15B Molar mass 122.02 g/mol Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

9-Borabicyclo[3.3.1]nonane dimer Identifiers Abbreviations 9-BBN InChI InChI=1/C16H30B2/c1-5-13-7-2-8 -14(6-1)17(13)19-18(20-17)15-9 -3-10-16(18)12-4-11-15/h13-16H ,1-12H2 InChIKey QQDDHBYRUTZKSX-UHFFFAOYAH Standard InChI InChI=1S/C16H30B2/c1-5-13-7-2- 8-14(6-1)17(13)19-18(20-17)15- 9-3-10-16(18)12-4-11-15/h13-16 H,1-12H2 Standard InChIKey QQDDHBYRUTZKSX-UHFFFAOYSA-N CAS number [21205-91-4] ChemSpider 21241191 SMILES   [H]1[B@]5([H][B@@]13C2CCCC3CCC2)C4CCCC5CCC4 Properties Chemical formula C16H26B2 Molar mass 244.04 g/mol Appearance white solid Density 0.894 g/cm3 Melting point 153–155 °C Solubility in water reacts Hazards EU index number not listed Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

9-Borabicyclo[3.3.1]nonane—tetrahydrofuran Identifiers InChI InChI=1/C12H23BO/c1-2-10-14(9-1)13-11-5-3-6-12(13)8-4-7-11/h11-13H,1-10H2 Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

9-Borabicyclo[3.3.1]nonane or 9-BBN is an organoborane compound. This colourless solid is used in organic chemistry as a hydroboration reagent.

9-BBN was first prepared by the thermal redistribution of 9-propyl-9-BBN, but it is more usually prepared by the reaction of 1,5-cyclooctadiene and borane adducts, usually in etherial solvents. The compound is commercially available as a solution in tetrahydrofuran and as a solid.

The solid is a hydride-bridged dimer: solutions in THF and other donor solvents contain monomeric adducts with a solvent molecule, eg 9-BBN·THF, although dimer (without solvent molecules) can be recrystallized from 1,2-dimethoxyethane (DME). The solid is relatively stable to air compared with other dialkylboranes, although it should be stored under an inert atmosphere. It may be handled for short periods in air, and a sample stored in air for one month showed only limited decomposition. Solutions of 9-BBN are handled using normal air-free techniques, eg Schlenk line and cannulas.

9-BBN is especially useful in Suzuki reactions. Its highly stereoselective addition on olefins allows the preparation of terminal alcohols by subsequent oxidative cleavage with hydrogen peroxide in aqueous potassium hydroxide. The steric demand of 9-BBN greatly suppresses the formation of the 2-substituted isomer compared to the use of borane.

Spectroscopic data

From Soderquist & Negron (1992):

• ¹H-NMR (300 MHz, C₆D₆): δ_H = 1.44–1.57 (m, 4H), 1.58–1.74 (m, 12H), 1.83–2.07 (m, 12H). A HETCOR experiment revealed that resonances from protons on each of the methylene carbons were superimposed upon one another.
• ¹³C-NMR (75 MHz, C₆D₆): δ_C = 20.2 (br, C-1,5), 24.3 (C-3,7), 33.6 (C-2,4,6,8)
• ¹¹B-NMR (96 MHz, C₆D₆): δ_B = 28

External links

• BASF brochure