The general procedure for the synthesis of 3-bromobenzothiophene from 2,3-dibromothiophene was as follows: first, the halogenated heterocycle (0.66 mmol) was dissolved in anhydrous THF (13.2 mL) and degassed by drumming in argon for a few minutes. Subsequently, PdCl2 (dppf) (27.0 mg, 0.033 mmol, 5.0 mol%), TMEDA (0.130 g, 1.12 mmol, 1.7 equiv) and NaBH4 (42.4 mg, 1.12 mmol, 1.7 equiv) were added sequentially. The reaction mixture was stirred at room temperature for appropriate time under argon protection and finally post-treated according to standard methods.