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
Highly enantioselective construction of CF3-bearing all-carbon quaternary stereocenters: Chiral spiro-fused bisoxazoline ligands with 1,1′-binaphthyl sidearm for asymmetric Michael-type Friedel-Crafts reaction
作者:Robert Li-Yuan Bao、Lei Shi、Kang Fu
DOI:10.1016/j.cclet.2021.10.062
日期:2022.5
A novel class of chiral spiro-fused bisoxazolineligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies
制备了一类具有深手性口袋的新型手性螺稠合双恶唑啉配体。开发的配体已用于镍催化的高对映选择性迈克尔型傅克反应,提供具有中等至优异产率(高达 99%)和良好至优异对映选择性(高达> 99.9% ee )。此外,提出的手性口袋模型表明,吲哚从β - CF 3 - β-二取代硝基烯烃的Re-面进攻是有利的。
Catalytic highly enantioselective transfer hydrogenation of β-trifluoromethyl nitroalkenes. An easy and general entry to optically active β-trifluoromethyl amines
An easy, general and highly enantioselective entry to optically active β-trifluoromethyl amines via organocatalytic transfer hydrogenation of β-trifluoromethyl nitroalkenes is presented.
The first examples of highly effective Henry reactions between nitroalkanes and aldehydes or trifluoromethyl ketones that proceed under catalyst-free and additive-free conditions, in a recyclable tap water medium, and at room temperature are reported. This process tolerates a broad range of aldehydes and trifluoromethyl ketones to give a series of β-nitro alcohol products in excellent yields. Such