Studies on Trifluoromethyl Ketones. VII. Ene Reaction of Trifluroacetaldehyde and Its Application for Synthesis of Trifluoromethyl Compounds.
摘要:
作为三氟甲基酮烯化反应研究的延伸,我们还研究了三氟乙醛的烯化反应。在路易斯酸(其中二氯化甲基铝的效果最好)存在的情况下,该醛作为一种良好的亲烯烃与各种烯化合物发生反应,但路易斯酸引起的醛聚合往往会降低烯反应的分离产率。使用 Dess Martin 试剂成功地将烯酮反应产物氧化为三氟甲基 β、γ-不饱和酮。烯反应产物还原后再用琼斯试剂氧化,得到饱和的三氟甲基酮。β、γ-不饱和酮在热分解过程中重新排列为 α、β-不饱和酮。得到的这些酮又转化为其他类型的三氟甲基化合物。因此,三氟乙醛的烯化反应为合成多种类型的三氟甲基化合物提供了一种通用方法。在这一衍生过程中,发现三氟甲基的取代基比癸基大得多。
Chemoselective Trifluoromethylation of Methyl Esters Using an Et<sub>3</sub>GeNa/C<sub>6</sub>H<sub>5</sub>SCF<sub>3</sub> Combination: Efficient Synthesis of Trifluoromethyl Ketones
作者:Yasuo Yokoyama、Kunio Mochida
DOI:10.1055/s-1997-961
日期:1997.8
Various trifluoromethyl ketones were synthesized from the corresponding methyl esters by effective nucleophilic trifluoromethylation using an Et3GeNa/C6H5SCF3 combination. This trifluoromethylation proceeded chemoselectively. When, cyclohexyl, i-propyl and t-butyl esters coexisted in the reaction system, only the methyl ester was easily transformed to the desired compounds in excellent yield. Furthermore, some protective groups were remained under this reaction condition.
Immobilisation of ketone catalyst: a method to prevent ketone catalyst from decomposing during dioxirane-mediated epoxidation of alkenes
作者:Choong Eui Song、Jin Seok Lim、Su Chang Kim、Kee-Jung Lee、Dae Yoon Chi
DOI:10.1039/b005604i
日期:——
Covalent attachment of trifluoromethyl ketone catalyst to a
solid support such as silica gel increased the stability of catalyst
dramatically, so solving an intrinsic problem of dioxirane-mediated
epoxidation of alkenes catalysed by ketones.
A convenient synthesis of hindered amines and α-trifluoromethylamines from ketones
作者:Charlotte L. Barney、Edward V. Huber、James R. McCarthy
DOI:10.1016/s0040-4039(00)97893-6
日期:——
Ketones and α-trifluoromethylketones were converted to primary, secondary, and tertiary amines in good to excellent yields by a reductive amination procedure utilizing TiCl4/NaCNBH3. The method provides the first direct route to α-trifluoromethylamines fromketones, and access to hindered amines fromketones which are unobtainable by Borch reducttve amination.
Trifluoromethyl
ketones were found to be coupled with arynes in three modes depending upon their substitution patterns, namely CâC bond cleavage, [2+2] cycloaddition and O-arylation.
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。