4,4-difluorobut-3-enylbenzene

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Typical Procedures for the Preparation of 1,1-Difluoro-1-alkenes (10) from Alkyl-substitued Difluoromethyl Sulfones (4): Under an argon atmosphere, into a Schlenk flask containing 1,1-difluoro-4-phenylbutyl phenyl sulfone (4g) (100 mg, 0.32 mmol) in THF (4 mL) at −20° C., was added dropwise via a syringe t-BuOK (224 mg, 2 mmol) in DMF (4 mL). The reaction mixture was stirred at −20° C.˜rt for 1 h, and the completion of the reaction was monitored by 19F NMR [δ −89.6 (d, J=46.6 Hz, 1F); −91.6 (dd, J=46.6 Hz, 24.8 Hz, 1F)]. The reaction was then quenched by adding aqueous NaCl solution (10 mL), followed by extraction with Et2O (15 mL×3). The combined organic phase was dried over anhydrous Na2SO4, filtered, and the solvent was removed. The crude product was purified by a flash chromatography to give 1,1-difluoro-4-phenyl-1-butene (10a) (46 mg, 85% yield) as a colorless liquid. The characterization data is consistent with that early reported.8h The reaction was then quenched by adding aqueous NaCl solution (10 mL) followed by extraction with Et2O (15 mL×3) The combined organic phase was dried over anhydrous Na2SO4 filtered the solvent was removed The crude product was purified by a flash chromatography