2-Thiophenecarboxaldehyde is prepared by the reaction of 2-Iodothiophene and carbon monoxide. The specific synthesis steps are as follows:
General procedure: A flask was charged with aryl iodide 1 (0.5 mmol), Pd(OAc)2 (2.4 mg, 0.01mmol), Na2CO3 (53.1 mg. 0.5 mmol), NaHCO3 (42.0 mg, 0.5 mmol), and PEG-400 (2 g) beforestandard cycles evacuation and backfilling with dry and pure carbon monoxide. Triethylsilane(162.8 μl, 1.0 mmol) was added successively. Then, the mixture was stirred at room temperaturefor the indicated time. At the end of the reaction, the reaction mixture was extracted with diethylether (3 × 10 mL). The organic phases were combined, and the volatile components wereevaporated under reduced pressure. The crude product was purified by column chromatography onsilica gel (petroleum ether / diethyl ether).