Catecholborane

Traditionally catecholborane is produced by treating catechol with borane (BH3) in a cooled solution of THF.

[1] In 2001, Herbert Brown and coworkers prepared catecholborane by treatment of tri-o-phenylene bis-borate with diborane.

This behavior is a consequence of the electronic influence of the aryloxy groups that diminish the Lewis acidity of the boron centre.

When catecholborane is treated with a terminal alkyne, a trans vinylborane is formed: The product is a precursor to the Suzuki reaction and is the only borane which stops at the alkene instead of reacting further to the alkane.

[3][4] Catecholborane may be used as a stereoselective reducing agent when converting β-hydroxy ketones to syn 1,3-diols.

Catecholborane molecule
NFPA 704 four-colored diamond Health 1: Exposure would cause irritation but only minor residual injury. E.g. turpentine Flammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propane Instability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorus Special hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid