Magnesium-Catalyzed Electrophilic Trifluoromethylation: Facile Access to All-Carbon Quaternary Centers in Oxindoles
作者:Dmitry Katayev、Harutake Kajita、Antonio Togni
DOI:10.1002/chem.201700851
日期:2017.6.22
The first example of a magnesium-catalyzed direct trifluoromethylation of 3-substituted oxindoles using an electrophilichypervalentiodinereagent is reported. The reaction proceeds under unprecedented mild conditions leading to the formation of an all-carbon quaternary center in oxindoles in high chemical yield and demonstrates excellent functional group tolerance. In addition to trifluoromethyl
We report the first terminal trifluoromethylation at aryl and alkyl ketones’ γ, δ, ε, or more remote sites via the selective C–C bond cleavage of cycloalkanols. The noncovalent interactions between alcohols and hypervalent iodines(III) reagents were disclosed to activate both alcohols and the Togni I reagent in the dual photoredox/copper catalysis for the transformation. This reaction was scalable
我们报告了通过环烷醇的选择性 C-C 键断裂在芳基和烷基酮的 γ、δ、ε 或更远的位点发生的第一个末端三氟甲基化。公开了醇和高价碘 (III) 试剂之间的非共价相互作用,以在双光氧化还原/铜催化转化中激活醇和 Togni I 试剂。该反应可扩展到克级合成,适用于结构复杂的类固醇三氟甲基化,并可扩展到五氟乙基化。
Synthesis of quaternary α-perfluoroalkyl lactams via electrophilic perfluoroalkylation
Efficient protocols enabling the rapid installation of trifluoromethyl, as well as further functionalized fluoroalkyl groups by an electrophilic perfluoroalkylation of lactam-derived ketene silyl amides (KSAs) using hypervalentiodinereagents 1...
Chemo-, Regio-, and Stereoselective Trifluoromethylation of Styrenes via Visible Light-Driven Single-Electron Transfer (SET) and Triplet–Triplet Energy Transfer (TTET) Processes
作者:Qing-Yu Lin、Xiu-Hua Xu、Feng-Ling Qing
DOI:10.1021/jo502040t
日期:2014.11.7
A process for tunable and chemo-, regio-, and stereoselective photocatalytic trifluoromethylation of styrenes was developed. Thermodynamically stable E-trifluoromethylated alkenes were prepared using Togni’s reagent in the presence of Ru(bpy)3Cl2·6H2O under visible light irradiation, whereas less thermodynamically stable Z-trifluoromethylated alkenes were obtained by employing Umemoto’s reagent and
Demonstrated herein is the construction of trifluoromethylated quaternarycarboncenters by an asymmetric radical transformation. Enantioenriched trifluoromethylated oxindoles were accessed using a hypervalent iodine‐based trifluoromethyl transfer reagent in combination with a magnesium Lewis acid catalyst and PyBOX‐type ligands to achieve up to 99 % ee and excellent chemical yields. Mechanistic studies
本文展示了通过不对称自由基转化的三氟甲基化季碳中心的构造。使用高价碘基三氟甲基转移试剂,结合路易斯酸镁催化剂和PyBOX型配体,可得到富含对映体的三氟甲基化吲哚,可实现高达99%的ee和优异的化学收率。通过实验和计算方法进行了机理研究,并提出了单电子转移诱导的S N 2型机理。因此,本例是有关使用高价碘基试剂通过这样的反应途径构建富含对映体的三氟甲基化碳中心的第一个报告。