Asymmetric Michael addition of α-fluoro-α-phenylsulfonyl ketones to nitroolefins catalyzed by phenylalanine-based bifunctional thioureas

Phenylalanine-based bifunctional thiourea derivatives promoted the asymmetric Michael addition of α-fluoro-α-phenylsulfonyl ketones to nitroolefins, affording enantiomerically enriched fluorine-containing multifunctional molecules containing adjoining chiral fluorine-substituted quaternary and tertiary centers in good yields and enantioselectivities.

Figure optionsDownload as PowerPoint slideHighlights
► Phenylalanine-based bifunctional thiourea derivatives promoted the asymmetric Michael addition of α-fluoro-α-phenylsulfonyl ketones to nitroolefins with good to excellent yield and stereoselectivity.
► A possible transition state model was proposed to explain the stereochemical results of the Michael addition.
► The bifunctional chiral thiourea catalyst activated the nitroolefin through H-bonding.