2-Biphenylboronic acid

233g (1.0mol) of 2-bromobiphenyl and 1400ml of THF were added to a 5000ml four-necked flask. Butyllithium solution (1.2mol) was added dropwise between -50℃ and -65℃. After the addition was complete, the temperature was maintained for 1 hour, and the reaction was monitored by gas chromatography until the reactants were fully reacted. 244.5g (1.3mol) of triisopropyl borate was added dropwise at -50℃, maintaining the temperature below -5℃. After the addition was complete, the temperature was maintained at this level for 1 hour, then allowed to rise naturally to room temperature. Hydrochloric acid was added to adjust the pH to 1, causing the mixture to separate into layers. The THF was removed under reduced pressure, and water was added to form a slurry. The mixture was then filtered, and the filter cake was further slurried with toluene and dried to obtain 169g of 2-biphenylboronic acid. The HPLC purity was 99.3%, and the yield was 85.5%.

Off-white powder

2-Biphenylboronic acid can undergo oxidation reactions and also can undergo a variety of cross-coupling reactions under the catalysis of metal palladium.

Reactant involved in:

• Suzuki-Miyaura cross-coupling reactions with arylhalides, dibromovinyl precursors, alkenyl tosylates and mesylates, and quinoline carboxylates
• Intramolecular Friedel-Crafts alkylation for synthesis of chiral tetralins
• Hydroxylation to phenols
• Oxidative coupling iwth alkynes

2-Biphenylboronic acid is a substrate used in a palladium-catalyzed cross-coupling with benzylic acetates providing diarylmethanes.