3-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)pyridine

626-60-8

73183-34-3

329214-79-1

In a nitrogen-protected glove box, a benzene solution of silica-3p-TPP ([P] content 0.11 mmol/g, 45.5 mg, 0.005 mmol P, 1 mol% P), anhydrous degassed benzene (0.8 mL), and [PdCl(η3-cinnamyl)]2 (0.65 mg, 0.00125 mmol, 0.5 mol% Pd) (0.2 mL) was added sequentially to an oven-dried 10 mL glass tube pre-fitted with a magnetic stirrer. After stirring for 5 min, KOAc (147 mg, 1.5 mmol), bis(pinacolato)diboron (2,140 mg, 0.55 mmol) and 3-chloropyridine (63.3 mg, 0.50 mmol) were added sequentially. The reaction tube was sealed with a screw cap and then removed from the glove box, and the reaction was stirred at 25°C for 10 hours. After completion of the reaction, the reaction mixture was filtered through a diatomaceous earth pad (eluting with Et2O) and the filtrate was concentrated under reduced pressure. To the residue was added the internal standard 1,1,2,2-tetrachloroethane, and the yield of the product 3-pyridineboronic acid pinacol ester was 95% as determined by 1H NMR. The crude product was purified by silica gel column chromatography to afford the target compound 3-pyridineboronic acid pinacol ester (87.0 mg, 0.40 mmol, 80% yield).