电化学条件下羧酸的脱酸交叉偶联反应的研究

羧酸廉价易得，稳定和使用方便， 因此羧酸参与的脱羧交叉偶联反应已经成为重要的有机合成方法之一。电解脱羧无需银等金属以及过硫酸盐等试剂，条件温和，因此本项目拟以电化学为技术，研究羧酸发生脱羧交叉偶联形成新的碳-碳和碳-杂键的反应。将重点研究酮酸的脱羧反应，首先拟研究无过渡金属体系中酮酸和胺类化合物以及杂环化合物的电解脱羧偶联反应，在此基础上，拟进一步研究酮酸和芳卤以及含有导向基团的芳环上 C-H 键的偶联反应，期望电解脱羧后得到的酰基中间体参与过渡金属催化的循环过程而完成偶联反应，实现电解过程和过渡金属催化循环过程的结合。期望发展电化学运用于脱羧交叉偶联反应的新技术。通过研究电化学条件下脱羧交叉偶联反应的机理，探索电化学有机合成的新现象、新规律，进一步发展高效、高选择性以及对环境友好的有机合成新方法。

Carboxylic acids are cheap, stable and easy to handle, hence decarboxylative cross coupling reaction is one of the most important synthetic methods. Without using silver metals and persulphates, electrochemical decarboxylation proceeds under mild reaction conditions. In this proposal, electrochemical supported decarboxylative coupling reaction to form new C-C and C-X bonds are studied. This work will focus on the study of the decarboxylation of α-keto acids. Firstly, transition metal-free coupling of α-keto acids with amines and heterocyclic compounds will be studied. Base on these results, the decarboxylative coupling of α-keto acids with aryl halides and directing group-containing aromatic C-H compounds will be further studied. Here we propose that by merging the electrochemical process and transition metal catalysis, the acyl intermediate will participate in the transition metal catalyzed cycle to furnish the coupling reaction. It represents the first study of applying the electrochemical technique into the decarboxylative cross-coupling of α-keto acids. This new methodology provides a remarkably straightforward means of construction of new chemical bonds high efficiently, selectively and environmental friendly.