Pyrrolidine-oxyimides: new chiral catalysts for enantioselective Michael addition of ketones to nitroolefins in water

Organocatalysis in aqueous media

“…The authors argue that reaction components together with water molecules are favourably coordinated via hydrogen bonding interactions, leading to robust transition state intermediates and hence to high selectivities for Michael adducts. 69 Miura employed perfluorooctanesulfonamide modified catalyst 27 using moderate catalyst loadings (10 mol%) for the Michael addition of benzyl malonate to α,β-unsaturated ketones (Table 1 -reaction 9). 70 Noteworthy, the novel catalyst performs in both solvents cyclohexanone and water at room temperature without additives, whereas slightly better performance was observed in cyclohexanone.…”

Green Asymmetric Organocatalysis

“…studied the same reaction with pyrrolidine–oxyimide catalyst C97 . This resulted in a high yield of the Michael adduct (Ar=Ph, 97 %), with 98:2 dr and 96 % ee . Water was used as a solvent, giving rise to excellent stereoselectivity of the reaction.…”

Organocatalysis: A Brief Overview on Its Evolution and Applications

“…There are also reports of a proline-pyrrolidine-oxyimide organocatalyst (21) being used in the asymmetric Michael addition of ketones (22) to nitroolefins (23) (Scheme 5). This catalyst allowed the synthesis of the Michael adducts with good yields (91-97%) and high enantioselectivity (up to 96% ee) when performed in water [12]. (25) using only 1,3-diaminopropane (26) and methanesulfonic acid (27) in water at room temperature [13].…”