To a 10 mL Schlenk reaction tube (F891410 reaction tube, 10 mL capacity, mill 14/20) was added the photocatalyst palladium chloride (2 mol%, 0.7 mg), 4,5-bis(diphenylphosphino)-9,9-dimethyloxanthene (L1) (3 mol%, 3.5 mg), 2-(dicyclohexylphosphino)biphenyl (L2) (4 mol%. 2.8 mg) and active aliphatic NHPI ester (0.2 mmol, 80.2 mg). The air in the tube was completely displaced with argon three times, and then 2,4,6-trimethylpyridine (0.2 mmol, 24.2 mg), 2 mL of N,N-dimethylacetamide (DMA) were added under argon atmosphere. The reaction system was stirred continuously for 15 h at room temperature under the irradiation of a 36 W blue LED lamp (using an IKA magnetic stirrer, RCT basic model, with a stirring speed of 500 rpm). After the reaction was completed, the reaction was quenched with H2O and the reaction solution was extracted with ethyl acetate (3*10 mL), and then the combined organic phases were concentrated by rotary evaporation (BUCHI rotary evaporator R-3). The concentrated residue was chromatographically separated by a column (C383040C with sand plate storage ball chromatography column, 35/20, effective length: 500 mm) to obtain the product.
