Enantioselective Michael Addition of Water

The enantioselective Michael addition using water as both nucleophile and solvent has to date proved beyond the ability of synthetic chemists. Herein, the direct, enantioselective Michael addition of water in water to prepare important β‐hydroxy carbonyl compounds using whole cells of Rhodococcus strains is described. Good yields and excellent enantioselectivities were achieved with this method. Deuterium labeling studies demonstrate that a Michael hydratase catalyzes the water addition exclusively with anti‐stereochemistry. Water as substrate and solvent: The Michael hydratase from Rhodococcus rhodochrous ATCC 17895 enables the direct enantioselective synthesis of secondary and tertiary alcohols in good yields and excellent enantioselectivities by a direct Michael addition of water in water. Deuterium labeling studies demonstrate that the water addition proceeds exclusively with anti‐stereochemistry.