In recent years, the stereoselective introduction of fluorine atom into molecules has drawn great attention in the field of medicinal and agricultural chemistry, due to its unique physical properties of organofluorine compounds. Furthermore, improvement of catalytic enantioselective methods for the construction of trifluoromethyl group containing stereogenicity has grown into a synthetic challenge, because of massive demands for the enantiopure drugs with high liphophilicity to improve efflux capacity. In particular, introduction of fluorine into γ-aminobutyric acid (GABA) and its derivatives is of great concentration as a result of their crucial role on the central nervous system (CNS), for example, Pregabalin, Baclofen, and Phenibut are imperative medicines for neurological disorders. Herein, the organocatalytic enantioselective Michael addition of dithiomalonates to β-trifluoromethyl nitroolefins has been focused “on water” condition using chiral urea catalyst, to access the enantioenriched Michael adducts with trifluoromethylated quaternary stereogenic centers, that scaffold for the aforementioned invaluable bioactive chiral compounds. This protocol has been successfully applied for the scalable one-pot synthesis of chiral GABA analogues with all-carbon-substituted quaternary stereogenic centers at the β-position, containing trifluoromethyl group, which might show highly interesting pharmaceutical properties. |
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