Proline-catalyzed aldol reactions

The Hajos–Parrish–Eder–Sauer–Wiechert and Barbas-List reactions in organic chemistry are a family of proline-catalysed asymmetric aldol reactions. In the 1970s, two research groups discovered (and published) almost simultaneously their discoveries of two related intramolecular reactions: Zoltan Hajos and David Parrish at Hoffmann-La Roche and Rudolf Wiechert et al at Schering AG. The original Hajos-Parrish procedure begins with an achiral triketone in dimethylformamide and 3% (molar) catalytic (S)‑(−)‑proline.

Source: Wikipedia — Proline-catalyzed aldol reactions (CC BY-SA 4.0)