9-(4-Bromophenyl)-3,6-dimethoxycarbazole (1.00 g, 2.62 mmol, 1.00 equiv), 4,4,5,5-tetramethyl-2-thiophen-2-yl-1,3,2-dioxaborolane (605 mg, 2.88 mmol, 1.10 equiv), Pd(dppf)Cl2 (95.7 mg, 131 μmol, 0.0500 equiv) and K2CO3 (2.17 g, 15.7 mmol, 6.00 equiv) were added to a 50 mL crimp cap vial and refilled with argon three times. 30 mL of degassed dimethylsulfoxide were added and the reaction mixture was heated to 90 °C. The reaction progress was monitored via TLC and after 1 h the product mixture was cooled to 22 °C. The mixture was poured into 100 mL water and extracted with ethyl acetate (3x 100 mL). The combined organic phases were washed with water (3x 200 mL) and brine (3x 200 mL), dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The crude product was purified via column chromatography on silica gel (eluent cyclohexane/ethyl acetate 20:1 --> 10:1) to yield 9-(4-thienylphenyl)-3,6-dimethoxycarbazole (940 mg, 2.44 mmol, 93% yield) as an off-white solid.
