Palladium-catalyzed direct β-arylation of ketones with diaryliodonium salts: a stoichiometric heavy metal-free and user-friendly approach
作者:Zhongxing Huang、Quynh P. Sam、Guangbin Dong
DOI:10.1039/c5sc01636c
日期:——
A user-friendly protocol for the Pd-catalyzed direct [small beta]-arylation of ketones is described, which avoids the use of stoichiometric heavy metals.
Fluoride anion-initiated bis-trifluoromethylation of phenyl aromatic carboxylates with (trifluoromethyl)trimethylsilane
作者:Kenjiro Takahashi、Yusuke Ano、Naoto Chatani
DOI:10.1039/d0cc04826g
日期:——
carboxylates with (trifluoromethyl)trimethylsilane (Me3SiCF3) that results in the formation of O-silyl-protected 2-aryl-1,1,1,3,3,3-hexafluoroisopropanols is reported. A phenoxide anion, generated during the trifluoromethylation of the phenyl carboxylate, also activates the Me3SiCF3, which permits a catalytic amount of the fluoride anion source to be used. Various functional groups, which can be used for further
Palladium-catalyzed redox cascade for direct β-arylation of ketones
作者:Zhongxing Huang、Guangbin Dong
DOI:10.1016/j.tet.2018.03.017
日期:2018.6
design and development of two palladium-catalyzed redox cascade methods that enable direct β-arylation of ketones. Palladium-catalyzed ketone dehydrogenation, aryl-X bond activation and conjugate addition were merged into a redox-neutral catalytic cycle. Non-metal-based aryl electrophiles were used as both the oxidant and the aryl source. The β-arylation with aryliodides was achieved site-selectively
The Influence of Perfluorinated Substituents on the Nucleophilic Reactivities of Silyl Enol Ethers
作者:Hans A. Laub、Daniel Gladow、Hans-Ulrich Reissig、Herbert Mayr
DOI:10.1021/ol301766w
日期:2012.8.3
The fluorinated trimethylsilyl enol ethers 3a–c were synthesized, and the kinetics of their reactions with the benzhydrylium ions 4 was studied by UV–vis spectroscopy in dichloromethane. Comparison with nonfluorinated analogues shows that replacement of CH3 by CF3 reduces the nucleophilic reactivity by 8 orders of magnitude, while the exchange of C6H5 by C6F5 retards the reactions by 4.5 orders of
合成了氟化的三甲基甲硅烷基烯醇醚3a – c,并通过在二氯甲烷中的紫外-可见光谱研究了它们与苯甲基铵离子4的反应动力学。与非氟化类似物的比较表明,用CF 3取代CH 3可使亲核反应性降低8个数量级,而用C 6 F 5交换C 6 H 5则使反应延迟4.5个数量级。
Synthesis of αβ-Unsaturated Trifluoromethyl Ketones from 4-Dimethylamino-1,1,1-trifluorobut-3-ene-2-one by Addition of Grignard Reagents
作者:Rebecca J. Andrew、John M. Mellor
DOI:10.1016/s0040-4020(00)00597-4
日期:2000.9
such as dimethylamine and they react with Grignard reagents to give αβ-unsaturated trifluoromethyl ketones in good yield by 1,4-addition followed by elimination. The generality of this procedure is contrasted with reactions based either on the use of organolithium nucleophiles, or the use of 4-alkoxy-αβ-unsaturated trifluoromethyl ketones as electrophilic partners.