Electrochemically Driven C-H Hydrogen Abstraction Processes with the Tetrachloro-Phthalimido-N-Oxyl (Cl 4 PINO) Catalyst
Electrochemically Driven C-H Hydrogen Abstraction Processes with the Tetrachloro-Phthalimido-N-Oxyl (Cl 4 PINO) Catalyst
复制标题
使用四氯邻苯二甲酰亚胺基 (Cl 4 PINO) 催化剂进行电化学驱动的 C-H 夺氢过程
DOI：
10.1002/elan.201800147
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发表时间：
2018
期刊：
影响因子：
3
通讯作者：
Buckingham M
中科院分区：
文献类型：
--
作者：
Buckingham M
在玻碳电极上生成自由基氧化还原介体四氯邻苯二甲酰亚胺基-N-氧基（Cl 4PINO），并研究伯醇和仲醇的模型氧化，特别关注反应速率和机理。一系列伯醇、仲醇和环状醇的双电子氧化反应被分解为基于C-H夺氢的初始步骤（速率常数k1，通过动力学同位素效应证实）和所得醇自由基与Cl 4PINO的快速自由基-自由基偶联，得到仅缓慢释放醛/酮和氧化还原介体前体回到溶液中的缩酮（速率常数k2）。原位电化学EPR揭示了Cl 4PINO对水分的敏感性。 DFT方法被用来确认和预测C-H夺氢反应性。
The radical redox mediator tetrachloro‐phthalimido‐N‐oxyl (Cl4PINO) is generated at a glassy carbon electrode and investigated for the model oxidation of primary and secondary alcohols with particular attention to reaction rates and mechanism. The two‐electron oxidation reactions of a range of primary, secondary, and cyclic alcohols are dissected into an initial step based on C−H hydrogen abstraction (rate constantk1, confirmed by kinetic isotope effect) and a fast radical‐radical coupling of the resulting alcohol radical with Cl4PINO to give a ketal that only slowly releases the aldehyde/ketone and redox mediator precursor back into solution (rate constantk2).In situelectrochemical EPR reveals Cl4PINO sensitivity towards moisture. DFT methods are applied to confirm and predict C−H hydrogen abstraction reactivity.