Catalytic Ring-Opening of Cyclic Alcohols Enabled by PCET Activation of Strong O–H Bonds
作者:Hatice G. Yayla、Huaiju Wang、Kyle T. Tarantino、Hudson S. Orbe、Robert R. Knowles
DOI:10.1021/jacs.6b06517
日期:2016.8.31
the redox-neutral isomerization of cyclic alcohols to linear ketones via C-C bond scission. Mechanistic studies demonstrate that key alkoxy radical intermediates in this reaction are generated via the direct homolytic activation of alcohol O-H bonds in an unusual intramolecular PCET process, wherein the electron travels to a proximal radical cation in concert with proton transfer to a weak Brønsted base
我们报告了一种新的光催化协议,用于通过 CC 键断裂将环醇氧化还原中性异构化为线性酮。机理研究表明,该反应中的关键烷氧基自由基中间体是通过在不寻常的分子内 PCET 过程中通过醇 OH 键的直接均裂活化而产生的,其中电子传播到邻近的自由基阳离子,同时质子转移到弱的布朗斯台德碱。显示有效的键强度考虑因素可以准确预测使用给定氧化剂/碱基对生成烷氧基自由基的可行性。
A Convenient Synthesis of 2-Naphthylcyclopentanones and 2-Naphthylcyclohexanones from 1-Naphthylcycloalkenes
作者:Maciej Góra、Michał K. Łuczyński、Janusz J. Sepioł
DOI:10.1055/s-2005-865298
日期:——
The oxidation of naphthylcycloalkenes with hydrogen peroxide or MCPBA followed by acid catalyzed rearrangement of diol (epoxide), afforded a series of naphthylcycloalkanones in a very simple manner. The conditions allow preparation of naphthylcycloalkanones on a multigram scale.
Herein, we first present a nickel-catalyzed arylation and alkenylation of tert-cyclobutanols with aryl/alkenyl triflates via a C–Cbondcleavage. An array of γ-substituted ketones was obtained in moderate-to-good yields, thus featuring earth-abundant nickel catalysis, broad substrate scope, and simple reaction conditions. Preliminary mechanistic experiments indicated that β-carbon elimination pathways
An efficient copper-catalyzed radical ring-opening halogenation with HX (aq) is described. This protocol features redox-neutral conditions, green halogen sources, and a broad substrate scope, providing practical access to distally chlorinated, brominated and iodinated alkyl ketones and alkyl nitriles with moderate to good yields.
Iron-Catalyzed Decarboxylative Olefination of Unstrained Carbon–Carbon Bonds Relying on Alkoxyl Radical Induced Cascade
作者:Pin Gao、Hao Wu、Jun-Cheng Yang、Li−Na Guo
DOI:10.1021/acs.orglett.9b02675
日期:2019.9.6
An iron-catalyzed decarboxylative olefination of unstrained carbon-carbon bonds via alkoxylradical induced C-C bond cleavage is presented. This protocol features mild conditions (room temperature, redox-neutral), good substrate scope and functional group compatibility, as well as excellent stereoselectivity, thus providing a facile access to the distal alkenyl ketones.