9-BBN

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
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 B1C2CCCC1CCC2
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
R-phrases (outdated)	R11 R14/15 R36/37/38
S-phrases (outdated)	S7/9 S16 S33 S7/8 S26 S37/39
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

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. 9-BBN is also known by its nickname 'banana borane'. This is because rather than drawing out the full structure, chemists often simply draw a banana shape with the bridging boron.

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

The compound is commercially available as a solution in tetrahydrofuran and as a solid. 9-BBN is especially useful in Suzuki reactions.

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.