反应详情

温度

25 °C

The following procedure for the preparation of allylpinacolboronate ester is representative. A 25-mL round-bottom flask equipped with a magnetic stir bar was charged with magnesium turnings (0.04 g, 1.65 mmol) and fitted with a rubber septum. The flask was purged with argon and charged with dry THF (2.3 mL) followed by PinBH (0.199 mL, 1.37 mmol). To the reaction mixture allylbromide (0.116 mL, 1.37 mmol) was added drop wise with constant stirring over five minutes at 25° C. After stirring for 30 min at 25° C., a second equivalent of allylbromide (0.116 mL, 1.37 mmol) was added. After 90 min of stirring at 25° C. the magnesium turnings were fully consumed and 11B NMR analysis confirmed the complete formation of allylpinacolboronate. Benzaldehyde (0.138 mL, 1.37 mmol) was then added and the reaction mixture was stirred for addition 12 h at 25° C. The reaction mixture was then diluted with hexane (5 mL), quenched with aqueous 1 M HCl (5 mL) and transferred to a separatory funnel. The organic layer was washed with aqueous 1 M NaOH (2×5 mL) and DI water (2×3 mL). The combined organic layers were dried over anhydrous MgSO4, filtered, and dried under vacuo (25° C., 1 Torr) to afford 1-phenyl-3-buten-1-ol as a clear colorless oil; 94.5% (0.190 g). The results for the other allylpinacolborane esters prepared by this method are summarized in Table 3.

1. customA 25-mL round-bottom flask equipped with a magnetic stir bar
2. customfitted with a rubber septum
3. customThe flask was purged with argon
4. additioncharged with dry THF (2.3 mL)
5. stirringAfter stirring for 30 min at 25° C.
6. customwere fully consumed
7. stirringthe reaction mixture was stirred for addition 12 h at 25° C
8. customquenched with aqueous 1 M HCl (5 mL)
9. customtransferred to a separatory funnel
10. washThe organic layer was washed with aqueous 1 M NaOH (2×5 mL) and DI water (2×3 mL)
11. dry with materialThe combined organic layers were dried over anhydrous MgSO4
12. filtrationfiltered
13. customdried under vacuo (25° C., 1 Torr)