9-Borabicyclo(3.3.1)nonane

The correct title of this article is 9-Borabicyclo[3.3.1]nonane. The substitution of any brackets is due to technical restrictions.

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. The compound exists as a hydride-bridged dimer, which easily cleaves in the presence of reducible substrates.^[1] 9-BBN is also known by its nickname 'banana borane'.^[2] This is because rather than drawing out the full structure, chemists often simply draw a banana shape with the bridging boron.^{[3][better source needed]}

9-Borabicyclo[3.3.1]nonane

Names
IUPAC name 9-Borabicyclo[3.3.1]nonane
Other names Borabicyclononane Banana borane
Identifiers
CAS Number	280-64-8 N
3D model (JSmol)	Interactive image
Abbreviations	9-BBN
ChemSpider	71299 Y
ECHA InfoCard	100.005.456
EC Number	206-000-9
PubChem CID	6327450
UNII	4K4J8L1OG9
CompTox Dashboard (EPA)	DTXSID3074781
InChI InChI=1S/C8H15B/c1-3-7-5-2-6-8(4-1)9-7/h7-9H,1-6H2 Y Key: FEJUGLKDZJDVFY-UHFFFAOYSA-N Y InChI=1/C8H15B/c1-3-7-5-2-6-8(4-1)9-7/h7-9H,1-6H2 Key: FEJUGLKDZJDVFY-UHFFFAOYAE
SMILES B1([H]3)(C2CCCC1CCC2)[H]B34C2CCCC4CCC2
Properties
Chemical formula	C16H30B2
Molar mass	244.04 g·mol−1
Density	0.894 g/cm3
Melting point	153 to 155 °C (307 to 311 °F; 426 to 428 K)
Solubility in water	Reacts
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H250, H260, H314
Precautionary statements	P210, P222, P223, P231+P232, P260, P264, P280, P301+P330+P331, P302+P334, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P335+P334, P363, P370+P378, P402+P404, P405, P422, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Preparation

9-BBN is prepared by the reaction of 1,5-cyclooctadiene and borane usually in ethereal solvents, for example:^[4][5]

The compound is commercially available as a solution in tetrahydrofuran and as a solid. 9-BBN is especially useful in Suzuki reactions.^[6][7][8]

Its highly regioselective addition on alkenes allows the preparation of terminal alcohols by subsequent oxidative cleavage with H₂O₂ in aqueous KOH. The steric demand of 9-BBN greatly suppresses the formation of the 2-substituted isomer compared to the use of borane.

See also

• Organoboron chemistry
• Boron

References

1. Brown, H. C. (1975). Organic Syntheses via Boranes. New York: John Wiley & Sons. ISBN 0-471-11280-1.
2. Stix, Gary. "The Straight Dope: A Q&A with the Prof behind the Good Science in Breaking Bad". Scientific American Blog Network. Nature America, Inc. Retrieved 18 June 2017.
3. Yale (2016-03-14). "Yale educational material: Hydroboration". Hydroboration Mechanics. Archived from the original on 13 August 2024.
4. Soderquist, John A.; Brown, Herbert C. (1981). "Simple, remarkably efficient route to high purity, crystalline 9-borabicyclo[3.3.1]nonane (9-BBN) dimer". J. Org. Chem. 46 (22): 4599–4600. doi:10.1021/jo00335a067.
5. Soderquist, John A.; Alvin, Negron (1982). "9-Borabicyclo[3.3.1]nonane Dimer". Organic Syntheses. 70: 169. doi:10.15227/orgsyn.070.0169.
6. Ishiyama, Tatsuo; Miyaura, Norio; Suzuki, Akira. "Palladium(0)-catalyzed reaction of 9-alkyl-9-borabicyclo[3.3.1]nonane with 1-bromo-1-phenylthioethene: 4-(3-cyclohexenyl)-2-phenylthio-1-butene". Organic Syntheses; Collected Volumes, vol. 9, p. 107.
7. Balog, A.; Meng, D.; Kamenecka, T.; Bertinato, P.; Su, D.-S.; Sorensen, E. J.; Danishefsky, S. J. (1996). "Total Synthesis of (−)-Epothilone A". Angew. Chem. Int. Ed. Engl. 35 (2324): 2801. doi:10.1002/anie.199628011.
8. Liu, J.; Lotesta, S. D.; Sorensen, E. J. (2011). "A concise synthesis of the molecular framework of pleuromutilin". Chem. Commun. 47 (5): 1500–1502. doi:10.1039/C0CC04077K. PMC 3156455. PMID 21079876.