Catalytic highly enantioselective transfer hydrogenation of β-trifluoromethyl nitroalkenes. An easy and general entry to optically active β-trifluoromethyl amines
Highly Enantioselective Construction of Trifluoromethylated All-Carbon Quaternary Stereocenters via Nickel-Catalyzed Friedel–Crafts Alkylation Reaction
A highlyenantioselectiveFriedel-Craftsalkylation reaction of indoles with β-CF(3)-β-disubstituted nitroalkenes was achieved using a Ni(ClO(4))(2)-bisoxazoline complex as a catalyst, which afforded indole-bearing chiral compounds with trifluoromethylated all-carbon quaternary stereocenters in good yields with excellent enantioselectivities (up to 97% ee). The transformation of one of the products
Access to Chiral GABA Analogues Bearing a Trifluoromethylated All-Carbon Quaternary Stereogenic Center through Water-Promoted Organocatalytic Michael Reactions
作者:Jae Hun Sim、Jin Hyun Park、Pintu Maity、Choong Eui Song
DOI:10.1021/acs.orglett.9b02320
日期:2019.9.6
dithiomalonates. Under on-water conditions, the reaction rates were remarkably accelerated as a result of enforced hydrophobic interactions between catalysts and reactants. Takemoto-type thiourea catalysts are very effective for this transformation, affording highly enantioenriched Michael adducts that provide simple access to chiral γ-aminobutyric acid (GABA) analogues with a β-trifluoromethylated quaternary
The squaramide-catalyzed asymmetric Michael/cyclization tandem reaction for the synthesis of chiral trifluoromethylated hydroxyimino tetrahydrobenzofuranones
An enantioselective synthesis of trifluoromethylated hydroxyimino tetrahydrobenzofuranones has been developed. 1,3-Dicarbonyl carbocyclic compounds react with β-CF3-β-disubstituted nitroalkenes in the presence of a chiral squaramide catalyst, providing efficient access to diverse hydroxyimino tetrahydrobenzofuranones featuring a trifluoromethyl group at the C3-position of an all-carbon quaternary stereocenter