Rhenium‐Catalyzed Decarboxylative Tri‐/Difluoromethylation of Styrenes with Fluorinated Carboxylic Acid‐Derived Hypervalent Iodine Reagents
作者:Yin Wang、Yunhui Yang、Congyang Wang
DOI:10.1002/cjoc.201900296
日期:2019.12
Herein, unprecedented rhenium‐catalyzed decarboxylative oxytri‐/difluoromethylation and Heck‐type trifluoromethylation of styrenes have been developed by using hypervalent iodine(III) reagents derived from cheap, stable, and easy‐handling fluorinated carboxylic acids. Mechanistic studies revealed a radical decarboxylative trifluoromethylation pathway occurring in these reactions.
Herein, we report the first example of group transfer radical addition of O-vinylhydroxylamine derivatives onto unactivatedalkenes. By utilizing O-vinylhydroxylamine derivatives as both the N- and C-donors, this reaction enables intermolecular carboamination of unactivatedalkenes in an atom economical fashion. As the process is initiated through N-radical addition followed by C-transfer, linear carboamination
在此,我们报告了第一个将 O-乙烯基羟胺衍生物基团转移自由基加成到未活化烯烃上的例子。通过使用 O-乙烯基羟胺衍生物作为 N 和 C 供体,该反应能够以原子经济的方式对未活化的烯烃进行分子间碳胺化。由于该过程是通过 N-自由基加成和 C-转移引发的,因此提供了线性碳胺化产物。这与烯烃的经典自由基碳官能化不同,后者通常有利于支链产物,因为它是由 C-自由基加成引发的。
Cyclic Iodine Reagents Enable Allylic Alcohols for Alkyl Boronate Addition/Rearrangement by Photoredox Catalysis
作者:Mingshang Liu、Hanchu Huang、Yiyun Chen
DOI:10.1002/cjoc.201800461
日期:2018.12
iodine(III) reagents enable the synthesis of cyclopentanones, cyclohexanones, and dihydrofuranones bearing α‐quaternary centers by photoredox catalysis. The reaction proceeds by the formation of the novel cyclic iodine(III) reagent‐allylic alcohol complex, which enables the first alkyl boronate addition and semi‐pinacol rearrangement of allylic alcohols with dual alcohol and olefin activation. The reaction
Asymmetric Chlorination/Ring Expansion for the Synthesis of α-Quaternary Cycloalkanones
作者:Qin Yin、Shu-Li You
DOI:10.1021/ol5005565
日期:2014.3.21
A highly enantioselective chlorination/ringexpansion cascade for the construction of cycloalkanones with an all-carbon quaternary center was realized (up to 97% ee). Oxa-cyclobutanol substrates were employed for the first time in the ringexpansionreactions, affording the functionalized dihydrofuranones in excellent enantioselectivity.
Rh(III)-Catalyzed Cyclopropanation Initiated by C–H Activation: Ligand Development Enables a Diastereoselective [2 + 1] Annulation of N-Enoxyphthalimides and Alkenes
作者:Tiffany Piou、Tomislav Rovis
DOI:10.1021/ja506579t
日期:2014.8.13
N-Enoxyphthalimides undergo a Rh(III)-catalyzedC–Hactivationinitiatedcyclopropanation of electron deficient alkenes. The reaction is proposed to proceed via a directed activation of the olefinic C–H bond followed by two migratory insertions, first across the electron-deficient alkene and then by cyclization back onto the enol moiety. A newly designed isopropylcyclopentadienyl ligand drastically