Tri-o-tolylphosphine → HCID 22221607, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 66 (0.48 g, 0.9 mmol) in xylene was added tributyl vinyl tin (0.28 g, 0.9 mmol) and tri-(o-tolyl)phosphine (0.055 g, 0.18 mmol). This mixture was purged with nitrogen for 15 minutes. Then palladium (II) chloride was added and the reaction was heated at 130° C. for 2 hours. The reaction was filtered and the solvent removed in vacuo. The residue was used in the next step without further purification. To a solution of 5-(tert-butyl-dimethyl-silanyloxy)-2-[4-tert-butyl-dimethyl-silanyloxy)-phenyl]-7-vinyl-benzofuran (0.4 g, 0.9 mmol) in THF (10 mL) was added 1.0M tetrabutyl ammonium fluoride (1.8 mL, 1.8 mmol) and the reaction mixture was stirred at room temperature 20 minutes. The reaction was diluted with ethyl ether and washed twice with water. The organic layer was dried over MgSO4 and the solvent removed in vacuo. The product was purified via flash chromatography, eluting with 50% ethyl acetate in hexane, to give 0.19 g of 2-(4-hydroxy-phenyl)-7-vinyl-benzofuran-5-ol 67: Mp=182-184° C.; 1H NMR (DMSO-d6) δ 9.86 (s, 1 H), 9.20 (s, 1 H), 7.73 (d, 2 H, J=8.6 HZ), 7.06 (s, 1 H), 6.89 (d, 2 H, J=8.8 Hz), 6.92 (dd, 1 H, J=16.7 Hz, 11.3 Hz), 6.84 (d, 1 H, J=2.3 Hz), 6.76 (d, 1H, J=2.3 Hz), 6.21 (dd, 1 H, J=17.8 Hz, 1.2 Hz), 5.54 (dd, 1 H, J=11.3 Hz, 1.2 Hz); MS 253 (M+H)+.

Provenance & Evidence