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。
Stereo- and Regioselectivity in Dynamic Gas-Phase Thermoisomerization (DGPTI): Novel Route to α-Campholanic Acid and Derivatives
作者:Georg Rüedi、Matthias Nagel、Hans-Jürgen Hansen
DOI:10.1021/ol034882t
日期:2003.7.1
Dynamic gas-phase thermoisomerization (DGPTI) of (-)-2-phenylisoborneols effects stereo- and regioselective ring opening under formation of (+)-trans-alpha-campholanic acid derivatives. Similarly, (-)-alpha-2-phenylfenchol underwent under DGPTI conditions ring opening to H-fencholic acid derivatives. In both cases, DGPTI led to cleavage of the weakest bond in the isomeric bicyclic structures. A reaction mechanism involving a diradical intermediate is supported by a deuterium labeling study.