(R)-Benzyl-2-[4-(trifluoromethyl)phenyl]-6,7-dihydro-5H-pyrrolo[2,1-c][1,2,4]triazolium Tetrafluoroborate

A flame dried round bottom flask is charged with triazolium salt (B3592, 13.0 mg, 0.031 mmol) and 2 mL of toluene. To this solution is added KHMDS (0.5 M in toluene, H0893) (61.0 µL, 0.031 mmol) via syringe and the solution is stirred at ambient temperature for 5 minutes. Toluene and HMDS are removed in vacuo by being placed under high vacuum for 1 hour. Toluene (3 mL) is added followed by a solution of the substrate (38.0 mg, 0.153 mmol) in 2 mL of toluene and the resulting solution is allowed to stir at ambient temperature for 24 hours. The reaction is quenched with 15% AcOH/toluene (2 mL) and the resulting solution is purified by flash column chromatography and eluted with a suitable solution of hexane and ethyl acetate (typically 6:1). Evaporation of solvent affords 35.7 mg (94%) of the desired product as colorless oil in 95% ee and 30:1 dr.