Development of C2-Symmetric Pyridine N-Oxides as New Nucleophilic Catalysts and Application for the Asymmetric Synthesis

我们发现在亲核碱催化剂DMAP和DMAPO的促进下，羧酸和醇在芳香酸酐上发生了有效的偶联反应。此外，我们还开发了一种在手性酰基转移催化剂存在下，通过用羧酸酐动力学拆分外消旋次醇制备光学活性羧酸酯和用混合酸酐生成非手性羧酸的方法。在这项研究中，我们成功地制备了新的吡啶氧化物化合物（DM-DMAPO和DM-DMQO）和其他亲核碱催化剂。此外，下列反应是在上述任何一种催化剂的存在下进行的：(1)由羧酸等价物和醇或胺生成酯或酰胺化合物的过程，(2)不对称酯化反应，(3)不对称醛醇和烯丙化反应。

We had found an effective coupling reaction of carboxylic acids and alcohols using aromatic anhydrides by the promotion of nucleophilic base catalysts, such as DMAP and DMAPO. Furthermore, we have developed a method for the preparation of optically active carboxylic esters by the kinetic resolution of racemic secondly alcohols using carboxylic anhydrides, and achiral carboxylic acids via mixed-anhydride formation method in the presence of chiral acyl-transfer catalysts. In this study, we succeeded in preparing new pyridine oxide compounds (DM-DMAPO and DM-DMQO) and other nucleophilic base catalysts. Moreover, the following reactions were performed in the presence of any of these as a catalyst, (1) a process for producing an ester or amide compound from a carboxylic acid equivalent and an alcohol or amine, (2) an asymmetric esterification reaction, and (3) an asymmetric aldol and allylation reactions.