Electrochemical generation of storable organic oxidants for use in sustainable catalytic transformations

循环流动电解槽的成功开发为第二个资助期提供了大量的机会，这种电解槽可以高效地分散阳极过程中产生的热量，甚至可以在以前难以捉摸的浓度下生产出敏感的氧化剂。高浓度的过氧碳酸氢钾溶液已被证明是一种有效的氧化剂，但过氧碳酸氢钾与有机试剂的相容性不佳以及氧化产物在水相中的高溶解度是阻碍进一步发展的关键障碍。这些问题将在第二个资助期解决。我们的第一个目标是开发出与有机底物有更好相容性的电生成氧化剂。在这种情况下，我们将针对含有过氧碳酸根阴离子的离子液体。在第二个项目中，我们将调查我们的反应堆是否允许接触到更多的亲脂性氧化剂，如过氧酸、过氧酸根、过硫酸盐或高价碘成分以及臭氧。我们将确定这些电化学生成的氧化剂的潜在应用，包括胺、苯胺、氨甚至氮的N-氧化，以及烯烃环氧化、Baeyer-Villiger氧化等。最后，我们将在两室环流反应器中将氧化剂的电化学生成与胞外氧化结合起来。电化学生成的氧化剂将与含有亲脂底物的有机相混合。相分离后，水相持续回流到电化学流动池中，有机产物相被分离出来。作为第一个模型反应，我们将使用合成具有商业意义的N-十二烷基-N，N-二甲胺N-氧化物。

The successful development of a circular flow electrolyzer, which dissipates the heat generated during the anodic process with such efficiency that even sensitive oxidizers can be produced in previously elusive concentrations, has opened up a wealth of opportunities for the second funding period. Highly concentrated peroxodicarbonate solutions have been shown to be potent oxidizers, but the unsatisfactory miscibility of potassium peroxodicarbonate with organic reagents and the high solubility of the oxidation product in the aqueous phase are key obstacles preventing further progress. These will be tackled in the second funding period. Our first goal is to electrogenerate oxidizers that are better miscible with organic substrates. In this context, we will target ionic liquids containing peroxodicarbonate anions. In a second project, we will investigate if our reactor allows to access more lipophilic oxidizers, such as peracids, peranhydrides, persulfates or hypervalent iodine components as well as ozone. We will identify potential applications for these electrochemically generated oxidizers, including N-oxidation of amines, anilines, ammonia or even of dinitrogen, as well as alkene epoxidations, Baeyer-Villiger oxidations etc. We will finally combine the electrochemical generation of the oxidants with ex-cell oxidations within a two-chamber loop reactor. The electrochemically generated oxidant will be mixed with an organic phase containing a lipophilic substrate. After phase separation, the aqueous phase will be continuously funneled back into the electrochemical flow cell, while the organic product phase will be separated off. As the first model reaction, we will use the synthesis of commercially meaningful N-dodecyl-N,N-dimethylamine N-oxide.