is one of the most attractive catalysts, especially for aromatic C–H functionalizations. However, stoichiometric amounts of oxidants and strong carbanions are required, and C–H tertiary alkylation, especially with electron-deficient alkylgroups, is unexplored. In this paper, we describe the development of iron-catalyzed selective C–H tertiary alkylations with heteroaromatics, in which an iron salt
Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
作者:Wenxin Chen、Zheng Liu、Jiaqi Tian、Jin Li、Jing Ma、Xu Cheng、Guigen Li
DOI:10.1021/jacs.6b06379
日期:2016.9.28
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h(-1) turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry
Copper-catalyzed direct alkylation of heteroarenes
作者:Cédric Theunissen、Jianjun Wang、Gwilherm Evano
DOI:10.1039/c6sc05622a
日期:——
process is reported for the directalkylation of C–H bonds in heteroarenes, privileged scaffolds in many areas of science. This reaction is based on the copper-catalyzed addition of alkyl radicals generated from activated secondary and tertiary alkyl bromides to a wide range of arenes, including furans, thiophenes, pyrroles, and their benzo-fused derivatives, as well as coumarins and quinolinones.
Di-, tri-, and tetrasubstituted β-lactones are accessible in a one-step procedure by a Reformatskyreaction of phenyl α-bromoalkanoates with ketones or aldehydes at a sacrificial indium anode. With indium powder comparable results are obtained. The yield of β-lactones is significantly lower, if zinc is used instead of indium.
Copper-Catalyzed Decarboxylative Functionalization of Conjugated β,γ-Unsaturated Carboxylic Acids
作者:Wei Zhang、Chengming Wang、Qiu Wang
DOI:10.1021/acscatal.0c03621
日期:2020.11.20
Copper-catalyzed decarboxylative coupling reactions of conjugated β,γ-unsaturated carboxylic acids have been achieved for allylic amination, alkylation, sulfonylation, and phosphinoylation. This approach was effective for a broad scope of amino, alkyl, sulfonyl, and phosphinoyl radical precursors as well as various conjugated β,γ-unsaturated carboxylic acids. These reactions also feature high regioselectivity