9-phenanthrenylboronic acid

5419-55-6

573-17-1

68572-87-2

The general procedure for the synthesis of 9-phenanthrenylboronic acid from triisopropyl borate and 9-bromophenanthrene is as follows: Step a: Preparation of 9-phenanthracenylboronic acid Under argon protection, 9-bromophenanthrene (1 g, 3.9 mmol) and triisopropyl borate (1.35 ml, 1.1 g, 5.85 mmol) were dissolved in anhydrous THF (30 ml) and the solution was cooled to -78 °C. Subsequently, n-BuLi (1.6 M hexane solution, 2.9 ml, 4.68 mmol) was added slowly dropwise over 1 h. The reaction temperature was maintained at -78 °C and stirring was continued for 1 h. The reaction mixture was then cooled to -78 °C. The reaction temperature was then adjusted to -78 °C. After that, the reaction mixture was slowly warmed up to -20°C, 2M HCl (20 ml) was added, and the temperature was continued to 18°C and stirring was continued for 1 hour. After completion of the reaction, ether (300 ml) was added for extraction, the organic phase was dried with MgSO4, filtered and concentrated under reduced pressure to afford the crude product 9-phenanthrenylboronic acid (770 mg, 89% yield) as a white solid, which can be used in subsequent reactions without further purification.