Dynamic Kinetic Resolution of N-Protected Amino Acid Esters via Phase-Transfer Catalytic Base Hydrolysis
作者:Eiji Yamamoto、Kodai Wakafuji、Yuho Furutachi、Kaoru Kobayashi、Takashi Kamachi、Makoto Tokunaga
DOI:10.1021/acscatal.8b00693
日期:2018.7.6
Asymmetric base hydrolysis of α-chiral esters with synthetic small-molecule catalysts is described. Quaternary ammonium salts derived from quinine were used as chiral phase-transfer catalysts to promote the base hydrolysis of N-protected amino acid hexafluoroisopropyl esters in a CHCl3/NaOH (aq) via dynamic kinetic resolution, providing the corresponding products in moderate to good yields (up to 99%)
描述了用合成的小分子催化剂对α-手性酯的不对称碱水解。奎宁衍生的季铵盐用作手性相转移催化剂,可通过动态动力学拆分促进CHCl 3 / NaOH(aq)中N保护的氨基酸六氟异丙基酯的碱水解,以中等至良好的收率提供相应的产物(最高99%)和最高96:4 er。使用DFT计算和伪过渡态(pseudo-TS)构象搜索进行的实验和计算机制研究提供了考虑立体选择性起源的TS模型。该模型表明,π-堆积和H-键相互作用在稳定TS结构中起重要作用。