Chemoselective Electrochemical Hydrogenation of Ketones and Aldehydes with a Well-Defined Base-Metal Catalyst.
Chemoselective Electrochemical Hydrogenation of Ketones and Aldehydes with a Well-Defined Base-Metal Catalyst.
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DOI：
10.1002/chem.202002075
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发表时间：
2020-11-06
期刊：
影响因子：
--
通讯作者：
Siewert I
中科院分区：
文献类型：
--
作者：
Fokin I;Siewert I
氢化反应是化学合成中最基本的官能团转化反应。在这里，我们介绍了一种通过原位形成Mn-H物种来氢化酮和醛的电化学方法。我们利用质子和电流作为H2和贱金属络合物的替代物来选择性地形成醇。该方法对C=O键的氢化比C=C键的氢化具有化学选择性。机理研究表明，催化剂的初始3 e−还原形成稳态物种[Mn 2（H− 1 L）（CO）6]−。随后，我们假设质子化，还原和内部质子转移形成的氢化物物种。最后，氢化物和质子向酮的转移产生醇，并且稳态物质通过还原再生。两个锰中心的相互作用和内部质子中继代表了酮和醛还原的关键特征，因为相应的单核复合物和没有质子中继的复合物几乎没有活性。 本文提出了一种利用质子和电流选择性地氢化酮形成相应醇的电化学方案。双核锰催化剂与内部质子中继器一起使用以促进反应。通过电化学方法和红外光谱电化学的研究，阐明了催化循环的机理。
Hydrogenation reactions are fundamental functional group transformations in chemical synthesis. Here, we introduce an electrochemical method for the hydrogenation of ketones and aldehydes by in situ formation of a Mn‐H species. We utilise protons and electric current as surrogate for H2 and a base‐metal complex to form selectively the alcohols. The method is chemoselective for the hydrogenation of C=O bonds over C=C bonds. Mechanistic studies revealed initial 3 e− reduction of the catalyst forming the steady state species [Mn2(H−1L)(CO)6]−. Subsequently, we assume protonation, reduction and internal proton shift forming the hydride species. Finally, the transfer of the hydride and a proton to the ketone yields the alcohol and the steady state species is regenerated via reduction. The interplay of two manganese centres and the internal proton relay represent the key features for ketone and aldehyde reduction as the respective mononuclear complex and the complex without the proton relay are barely active. An electrochemical protocol is herein presented for the hydrogenation of ketones forming selectively the corresponding alcohols using protons and electric current. A dinuclear manganese catalyst is used with an internal proton relay to facilitate the reaction. Investigation by means of electrochemical methods and IR spectroelectrochemistry shed light on the catalytic cycle.
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影响因子：
37.8
作者：
Bondue, Christoph J.;Calle-Vallejo, Federico;Koper, Marc T. M.
通讯作者：
Koper, Marc T. M.
影响因子：
6.2
作者：
Barrón, D;Barbosa, J
通讯作者：
Barbosa, J
影响因子：
4.3
作者：
Du, Jia-Pei;Wilting, Alexander;Siewert, Inke
通讯作者：
Siewert, Inke
影响因子：
15
作者：
Costentin, Cyrille;Passard, Guillaume;Saveant, Jean-Michel
通讯作者：
Saveant, Jean-Michel
影响因子：
6.2
作者：
DANIELE, S;UGO, P;BONTEMPELLI, G
通讯作者：
BONTEMPELLI, G