Effective Promotion of Proline‐Catalyzed Aldol Reaction in Water by Bile Acid Salt Surfactants

Proline-catalyzed aldol reaction of aromatic aldehydes with cyclohexanone was successfully carried out in water without any cosolvent in presence of catalytic amounts of bile acid salt surfactants. The bile acid salts, acting as surfactants, facilitate the dispersion of nonpolar substrates, enabling efficient reaction conditions “in presence of water” which exploit the role of water beyond its simple characteristic as a solvent. While enantioselectivity is moderate, the high yields achieved reflect the potent synergy between proline and sodium deoxycholate (NaDC), underscoring the feasibility of water-exclusive processes in synthetic organic chemistry.