title: Water-Enabled Catalytic Asymmetric Michael Reactions of Unreactive Nitroalkenes: One-Pot Synthesis of Chiral GABA-Analogs with All-Carbon Quaternary Stereogenic Centers.
abstract: Water enables new catalytic reactions for otherwise unreactive substrate systems. Under the "on water" reaction conditions, extremely unreactive β,β-disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of highly enantioenriched Michael adducts with all-carbon-substituted quaternary centers. The developed "on water" protocol was successfully applied for the scalable one-pot syntheses of chiral GABA analogs with all-carbon quaternary stereogenic centers at the β-position, which might show highly interesting pharmaceutical properties.
authors.affiliation: Department of Chemistry, Sungkyunkwan University, Suwon, 440-746, Korea.
authors.forename: Jae Hun
authors.identifier: 0000-0001-9972-6140
authors.initials: JH
authors.lastname: Sim
authors.affiliation: Department of Chemistry, Sungkyunkwan University, Suwon, 440-746, Korea.
authors.forename: Choong Eui
authors.identifier: 0000-0001-9221-6789
authors.initials: CE
authors.lastname: Song
keywords: Michael addition; amino acids; asymmetric organocatalysis; stereogenic centers; water