Nitrogen → 5-Isoxazolemethanol, 3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-, 5-acetate

Participants

Reaction Conditions

Reaction Steps

To a 500 mL flask (under N2 (g)) was added dichlorobis(acetonitrile)palladium(II) (0.551 g, 2.12 mmol) and dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (3.50 g, 8.53 mmol). To the solids was sequentially added a solution of (4-bromo-3-methylisoxazol-5-yl)methyl acetate (24.8 g, 106 mmol) in 1,4-dioxane (65 mL), Et3N (44.3 mL, 318 mmol), and 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (24 mL, 160 mmol). The flask was sequentially evacuated and purged under N2 and this process was repeated three times. The reaction mixture was heated to 110° C. (under a constant stream of N2 (g)) and allowed to stir for ˜4 h. LC-MS analysis at this point showed complete conversion of the starting bromo-isoxazole. The reaction mixture was cooled to room temperature and EtOAc (100 mL) was added. After 15 min of stirring, the suspension was filtered over a pad of Celite. The filter cake was washed with EtOAc (3×100 mL), concentrated in vacuo, and the solvent was switched using 1,4-Dioxane (2×50 mL). The borate ester with used without further purification.

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