Fig. 2.

Substrate scope of N-aryl amino acids and secondary α-bromoketones. Reactions were performed with 1 (0.1 mmol), 2 (0.2 mmol), DPZ (0.5 × 10⁻³ mmol), C1 (0.01 mmol), NaHCO₃ (0.3 mmol), and 3 Å MS (50 mg) in 1,2-dimethoxyethane (1.5 mL) at 0 °C. Yields were determined from the isolated material after chromatographic purification. Enantiomeric excesses were determined by HPLC analysis on a chiral stationary phase. ^aOn a 1.0 mmol scale and 60 h, yield of 3a = 75% and ee = 94% (2 × 3 W blue LED). ^bCatalyst C2 was used instead of C1