Diisopropylethylamine → 5,6-Difluorotricyclo[7.2.1.02,7]dodeca-2(7),3,5,10-tetraene

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Reaction Conditions

Reaction Steps

Trifluoro-methanesulfonic acid 2-cyclopent-3-enylmethyl-3,4-difluoro-phenyl ester (340 mg, 0.99 mmol), was dissolved In DMF (5 mL) under a N2 atmosphere and treated with diisopropylethylamine (0.26 mL, 1.5 mmol, potassium acetate (981 mg, 10.0 mmol) and tri-o-tolylphosphine (12 mg, 0.04 mmol). This mixture was stirred and degassed (3 vacuum/N2 purge cycles) and then treated with palladium acetate (5 mg, 0.02 mmol). After 20 min. the mixture was warmed to 100° C. for 18 hours, cooled and poured into brine (50 mL). The resulting mixture was extracted with hexanes (4×25 mL) and the combined organic layer was washed with a sat. aq. NaHCO3 soln. (10 mL), water (H2O) (10 mL), brine (10 mL), dried (magnesium sulfate (MgSO4)), filtered and and chromatographed on silica gel to provide an oil (110 mg, 60%). (TLC hexanes Rf 0.58). 1H NMR (CDCl3) δ 6.80 (ddd, J=6.6, 8.1, 8.3 Hz, 1H), 6.68 (m, 1H), 6.17 (dd, J=5.5, 2.8 Hz, 1H), 5.77 (dd, J=5.5, 2.8 Hz, 1H), 3.29 (br s, 1H), 2.96 (br s, 1H), 2.84 (AB dd, J=17.9, 5.0 Hz. 1H), 2.54 (AB d, J=17.9 Hz, 1H), 2.19 (m, 1H), 1.77 (d, J=10.5 Hz, 1H). GCMS m/e 192 (M+).

Provenance & Evidence