Generations and Reactions of Reactive Organic Cations Using Flow Redox Systems

最近我们开发了“阳离子池”方法，它包括通过低温电解产生高活性的碳正离子，然后与各种亲核试剂反应。微流控反应器在化学小型化的潮流中受到了极大的关注，它们有望为化学合成带来一场革命性的变革。微流反应器易于调节的优点和组合反应器的可能性对于构建用于有机转化的流动式氧化还原体系是非常有用的。在这个概念的基础上，我们利用微流电化学反应器发展了“阳离子流动”法，它涉及到通过低温电解产生高活性碳正离子。这种方法能够操纵碳正离子中间体来实现直接氧化C-C键的形成。在“阳离子流”方法的基础上，通过简单的流切换即可实现连续的序贯组合合成。作为“阳离子流动”方法的扩展，发展了一种电化学配对微流体系，该体系包括碳正离子的阳极生成和碳亲核试剂的阴极生成，然后它们的反应实现直接的C-C键形成。在没有故意添加支持电解液的情况下，使用电化学微流系统也实现了几种有机化合物的阳极甲氧基化。

Recently we have developed the "cation pool" method, which involves generation of highly reactive carbocations by low temperature electrolysis followed by reactions with a variety of nucleophiles. Micro flow reactors have received significant interest in the stream of downsizing of chemistry, and they are expected to make an innovative and revolutionary change for chemical synthesis. The advantages of microflow reactors of easy modulation and the possibility of combining reactors are quite useful to construct flow type redox systems for the organic transformations. On the basis of this concept we have developed "cation flow" method using microflow electrochemical reactors, which involves generation of highly reactive carbocations by low temperature electrolysis. This method enables the manipulation of carbocation intermediates to achieve direct oxidative C-C bond formation. Based on the "cation flow" method, continuous sequential combinatorial synthesis can be accomplished by simple flow switching. As an extension of the "cation flow" method, an electrochemical paired micro flow system that involves concurrent anodic generation of carbocations and cathodic generation of carbon nucleophiles followed by their reactions to achieve straightforward C-C bond formation has been developed. Anodic methoxylation of several organic compounds have also been achieved in the absence of intentionally added supporting electrolyte using an electrochemical microflow system.