Reacción #1833250

Ecuación de reacción

Benzo[d][1,3]dioxole

sec-Butyllithium

2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

→

title compound

Rendimiento 34.5%

2-(Benzo[d][1,3]dioxol-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Rendimiento 34.5%

Disolventes

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   Otrothe temperature below −100° C
2. 2
   Otrothe temperature below −100° C
3. 3
   Temperaturato warm to room temperature
4. 4
   Otropartitioned between diethyl ether and water
5. 5
   ExtracciónThe organic phase was extracted with water once again
6. 6
   ExtracciónThe product was extracted with diethyl ether
7. 7
   Otrothe organic phase was dried
8. 8
   Concentraciónconcentrated under vacuum
9. 9
   OtroThe product was purified by flash chromatography (silica gel)

Procedimiento

Benzo[d][1,3]dioxole (3.05 g, 25 mmol) was dissolved in tetrahydrofuran (50 mL) and cooled to −108° C. utilizing a tetrahydrofuran/liquid nitrogen bath. sec-Butyllithium (1.4 M in cyclohexane; 19.64 mL, 27.5 mmol) was added dropwise, keeping the temperature below −100° C. The reaction mixture was then stirred at temperatures between −100° C. and −108° C. for 2 h to ensure complete deprotonation. 2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (4.65 g, 25.00 mmol) was then added to the reaction mixture dropwise, keeping the temperature below −100° C. The reaction mixture was then allowed to warm to room temperature and partitioned between diethyl ether and water. The organic phase was extracted with water once again and the aqueous phases combined and acidified to pH 4 with HCl. The product was extracted with diethyl ether and the organic phase was dried and concentrated under vacuum. The product was purified by flash chromatography (silica gel) to provide the title compound as a white solid (2.14 g, 34.5%): 1H NMR (300 MHz, CDCl3) δ 7.21 (dd, J=7.6, 1.4 Hz, 1H), 6.90 (dd, J=7.7, 1.5 Hz, 1H), 6.82 (t, J=7.6 Hz, 1H), 6.02 (s, 2H), 1.36 (s, 12H); EIMS m/z 248.

Fuente