Li Guanlin, Zhao Ling, Luo Yicong, Peng Youbin, Xu Kai, Huo Xiaohong, Zhang Wanbin
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, Frontiers Science Center for Transformative Molecules, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, P. R. China.
College of Chemistry, Zhengzhou University, Zhengzhou, 450052, P. R. China.
Chemistry. 2022 Apr 27;28(24):e202200273. doi: 10.1002/chem.202200273. Epub 2022 Mar 24.
Asymmetric desymmetrization has been demonstrated to be a powerful strategy for building stereocenters in asymmetric synthesis. Herein, a Pd/Cu catalyzed asymmetric desymmetrization reaction with a simple geminal dicarboxylate is reported. A wide scope of imino esters bearing an aryl or heteroaromatic group were compatible with this bimetallic catalytic system. The reactions proceeded smoothly, giving the desired products in good yields with high to excellent regio-, diastereo-, and enantioselectivity (up to 20 : 1 branched:linear, >20 : 1 dr, >99 % ee). Notably, the reaction favored branched selectivity, which is unusual for the Pd-catalyzed allylic alkylation reaction. In addition, the standard product could be easily transformed to other valuable molecules such as chiral allylic alcohols, carbamates, and organic boron compounds. Furthermore, DFT calculations were conducted to explain the origin of the branched selectivity.
不对称去对称化已被证明是不对称合成中构建立体中心的一种有效策略。在此，报道了一种钯/铜催化的与简单偕二羧酸酯的不对称去对称化反应。多种带有芳基或杂芳基的亚氨基酯与这种双金属催化体系兼容。反应顺利进行，以良好的产率得到所需产物，具有高至优异的区域选择性、非对映选择性和对映选择性（支链:直链高达20 : 1，非对映体比例>20 : 1，对映体过量>99 %）。值得注意的是，该反应有利于支链选择性，这对于钯催化的烯丙基烷基化反应来说是不寻常的。此外，标准产物可以很容易地转化为其他有价值的分子，如手性烯丙醇、氨基甲酸酯和有机硼化合物。此外，进行了密度泛函理论计算以解释支链选择性的起源。
