338998-93-9

534-22-5

25015-63-8

338998-93-9

The general procedure for the synthesis of 2-methylfuran-5-boronic acid pinacol ester from 2-methylfuran and pinacolborane is as follows: according to the reaction scheme for the boronation of Example 9-aromatic five-membered heterocyclic rings (Fig. 2a), to a scintillation vial fitted with a magnetic stirring bar were added a cobalt complex of 1-4,2-methylfuran (0.01 mmol), 2-methylfuran (1 mmol) and pinacolborane ( 1 mmol). The reaction process was monitored by analyzing an aliquot of the mixture by GC-FID. The reaction mixture was stirred at room temperature until the reaction was complete and subsequently quenched by exposure to air. The resulting solid was dissolved in CDCl3 and filtered through a Pasteur pipette fitted with a silicone plug, followed by 1H and 13C NMR spectroscopy without further purification. If the reaction conditions need to be adjusted, the above reaction can be carried out in 2 ml of tetrahydrofuran (THF). Figure 2(a) demonstrates the percentage conversion of cobalt complexes 1-4, and the values in parentheses are the isolated yields. In addition, Figure 2(b) describes in detail the other boronation products achieved using cobalt complexes 2 and 3 according to the aforementioned reaction parameters.