3D model (JSmol)
|Molar mass||119.92 g/mol|
|Density||1.125 g/cm3, liquid|
|Melting point||12 °C (54 °F; 285 K)|
|Boiling point||50 °C (122 °F; 323 K) at 50 mmHg|
|R-phrases (outdated)||R11, R14, R34|
|S-phrases (outdated)||S16, S26, S36/37/39, S43, S45|
|Flash point||2 °C (36 °F; 275 K)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis and structure
Traditionally catecholborane is produced by treating catechol with borane (BH3) in a cooled solution of THF. However, this method results in a loss of 2 mole equivalents of the hydride. Nöth and Männig devised a more economical method involves the reaction of alkali-metal boron hydride (LiBH4, NaBH4, of KBH4) with tris(catecholato)bisborane in an ethereal solvent such as diethyl ether. In 2001 Herbert Brown released an additional procedure for catecholborane synthesis. His method involves treating tri-O-phenylene bis-borate with diborane in a solution of either triglyme or tetraglyme. Brown claimed his method produces 85% yield of 97% pure product, catecholborane.
Unlike borane itself or alkylboranes, catechol borane exists as a monomer. This behavior is a consequence of the electronic influence of the alkoxy groups that diminish the Lewis acidity of the boron centre. Pinacolborane adopts a similar structure.
Catechol borane is less reactive than borane itself.
Preparation of an organoborane
Reduction of β-hydroxy ketones
- Process for producing catecholborane - Patent 4739096
- New Economical, Convenient Procedures for the Synthesis of Catecholborane
- Janice Gorzynski Smith. Organic Chemistry: Second Ed. 2008. pp 1007
- Norio Miyaura (1990). "Discussion Addendum for:PALLADIUM-CATALYZED REACTION OF 1-ALKENYLBORONATES WITH VINYLIC HALIDES: (1Z,3E)-1-PHENYL-1,3-OCTADIENE". Org. Synth.; Coll. Vol., 68, p. 130
- "Reduction of Hydroxy Ketones with Catecholborane. A Stereoselective Approach to the Synthesis of Syn 1,3-Diols" (PDF). Retrieved 25 April 2017.