Potassium vinyltrifluoroborate → 1-t-Butyl 2-methyl (2S,4R)-4-{[(4-vinyl-1,3-dihydro-2H-isoindol-2-yl)carbonyl]oxy}pyrrolidine-1,2-dicarboxylate

Participants

Reaction Steps

To a solution of 1-t-butyl 2-methyl (2S,4R)-4-{[(4-bromo-1,3-dihydro-2H-isoindol-2-yl)carbonyl]oxy}pyrrolidine-1,2-dicarboxylate (10.0 g, 21.3 mmol) in EtOH (200 mL) was added potassium vinyltrifluoroborate (4.28 g, 32 mmol) and Et3OH (4.5 mL, 32 mmol) followed by dichloro[1,1-bis(diphenylphosphino)ferrocene]palladium (II) chloride dichloromethane adduct (175 mg, 0.21 mmol). The reaction mixture was heated to reflux for 6 hours, cooled to RT, diluted with 10% aqueous KHSO4. The EtOH was removed by evaporation in vacuo. The aqueous residue was extracted with EtOAc, and the organic phase washed with brine, dried over Na2SO4. The solvent was evaporated, and the crude product was purified by chromatography on silica eluting with 40-60% EtOAc/hexane to give, after evaporation, the title compound (8.18 g). LRMS (ESI) m/z 417.2 [(M+H)+; calcd for C22H29N2O6: 417.2].

Provenance & Evidence