Noncovalent Immobilization of Molecular Electrocatalysts for Chemical Synthesis: Efficient Electrochemical Alcohol Oxidation with a Pyrene-TEMPO Conjugate.
Noncovalent Immobilization of Molecular Electrocatalysts for Chemical Synthesis: Efficient Electrochemical Alcohol Oxidation with a Pyrene-TEMPO Conjugate.
复制标题
DOI：
10.1002/anie.201704921
复制
发表时间：
2017-07-17
期刊：
影响因子：
--
通讯作者：
Stahl SS
中科院分区：
文献类型：
--
作者：
Das A;Stahl SS
有机合成的电催化方法可以为传统的氧化还原反应提供可持续的替代方案，但需要策略来提高为此目的设计的分子催化剂的性能。本文中，我们描述了芘系连的克里思衍生物（克里思= 2，2，6，6-四甲基哌啶基-N-氧基）的合成，其经历了容易的原位非共价固定到碳布电极上。循环伏安法和控制电位电解研究表明，固定化催化剂表现出更高的活性相对于，4-乙酰胺基-TEMPO，一个电子相似的均相催化剂。在一系列醇底物的制备电解实验中，周转数和频率分别接近2000和4000 h-1。该方法的合成效用在空间位阻羟甲基嘧啶前体氧化成重磅炸弹药物瑞舒伐他汀中得到进一步证明。表演环节：非共价固定的TEMPO基催化剂拴芘的碳布电极上的结果在非常有效的催化醇氧化。简易的原位催化剂固定化方案展示了一种策略，以实现改进的催化性能，可以在电有机合成中找到广泛的用途。
Electrocatalytic methods for organic synthesis could offer sustainable alternatives to traditional redox reactions, but strategies are needed to enhance the performance of molecular catalysts designed for this purpose. Herein, we describe the synthesis of a pyrene-tethered TEMPO derivative (TEMPO = 2,2,6,6-tetra-methylpiperidinyl-N-oxyl) that undergoes facile in situ non-covalent immobilization onto a carbon-cloth electrode. Cyclic voltammetry and controlled potential electrolysis studies demonstrate that the immobilized catalyst exhibits much higher activity relative to, 4-acetamido-TEMPO, an electronically similar homogeneous catalyst. Turnover numbers and frequencies approach 2000 and 4000 h−1, respectively, in preparative electrolysis experiments with a series of alcohol substrates. The synthetic utility of the method is further demonstrated in the oxidation of a sterically hindered hydroxymethylpyrimidine precursor to the blockbuster drug, rosuvastatin. Performance link: Non-covalent immobilization of a TEMPO-based catalyst tethered to pyrene on a carbon-cloth electrode results in very efficient catalytic alcohol oxidation. The facile in situ catalyst immobilization protocol demonstrates a strategy to achieve improved catalytic performance that could find widespread utility in electroorganic synthesis.