反应详情

Methyl 4-benzyloxy-3-bromobenzoate (1.61 g, 5.0 mmol), caesium carbonate (4.89 g, 15.0 mmol), (E)-2-buten-2-yl boronic acid (600 mg, 6.0 mmol) and [1,1′-bis(diphenylphosphino)ferrocenyl]palladium (II) chloride (204 mg, 0.25 mmol) were dissolved in anhydrous tetrahydrofuran (100 ml), water (10 ml) was added and the mixture was stirred and held at reflux under an atmosphere of nitrogen for 16 hours. Upon cooling the solvent was removed in vacuo and the mixture partitioned between dichloromethane and water. The organic layer was separated, the solvent removed in vacuo and the residue subjected to column chromatography on silica. Elution with 5% ethyl acetate in petroleum ether afforded methyl (Z)-4-benzyloxy-3-(1-methyl-propenyl)-benzoate (600 mg, 41%) as a colourless solid. 1H NMR (DMSO-d6) 7.88 (1H, dd), 7.59 (1H, d), 7.40 (4H, m), 7.34 (1H, m), 7.23 (1H, d), 5.57 (1H, q), 5.21 (2H, s), 3.82 (3H, s), 1.94 (3H, s), 1.38 (3H, d).

1. temperatureat reflux under an atmosphere of nitrogen for 16 hours
2. temperatureUpon cooling the solvent
3. customwas removed in vacuo
4. customthe mixture partitioned between dichloromethane and water
5. customThe organic layer was separated
6. customthe solvent removed in vacuo
7. washElution with 5% ethyl acetate in petroleum ether