Reaction #2045083

Reaction equation

3-bromo-9H-carbazole

9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole

K3PO4

→

9H,9′H-3,3′-bicarbazole

Yield 73.1%

Solvents

toluene

water

Conditions

Workup

1. 1
   Extractionthe reaction mixture was extracted with dichloromethane
2. 2
   Washwashed with brine
3. 3
   DryingThe combined organic solutions were dried over Na2SO4
4. 4
   Filtrationfiltered
5. 5
   Otherthe solvent was evaporated
6. 6
   Otherto yield a crude product, which
7. 7
   Otherwas recrystallized from DCM/hexane (1/1, v/v, 1200 mL)

Procedure

A mixture solution of 3-bromo-9H-carbazole (6.75 g, 27.4 mmol), 9-phenyl-3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-9H-carbazole (12.15 g, 32.9 mmol), Pd2(dba)3 (0.251 g, 0.274 mmol), SPhos (0.450 g, 1.097 mmol) and K3PO4 (25.3 g, 110 mmol) in toluene (500 mL) and water (50 mL) was refluxed under nitrogen for 10 h. After cooling to room temperature, the reaction mixture was extracted with dichloromethane and washed with brine. The combined organic solutions were dried over Na2SO4, filtered, and the solvent was evaporated to yield a crude product, which was recrystallized from DCM/hexane (1/1, v/v, 1200 mL) to yield 9H,9′H-3,3′-bicarbazole (6.66 g, 59%) as a yellow solid.

Source