Dynamic Kinetic Resolution of N-Protected Amino Acid Esters via Phase-Transfer Catalytic Base Hydrolysis
Dynamic Kinetic Resolution of N-Protected Amino Acid Esters via Phase-Transfer Catalytic Base Hydrolysis
复制标题
通过相转移催化碱水解动态动力学拆分 N-保护氨基酸酯
DOI：
10.1021/acscatal.8b00693
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发表时间：
2018
期刊：
影响因子：
12.9
通讯作者：
Tokunaga Makoto
中科院分区：
文献类型：
--
作者：
Yamamoto Eiji;Wakafuji Kodai;Furutachi Yuho;Kobayashi Kaoru;Kamachi Takashi;Tokunaga Makoto
研究了合成的小分子催化剂催化α-手性酯的不对称碱水解反应。以奎宁衍生的季铵盐为手性相转移催化剂，在CHCl 3/NaOH（aq）体系中，通过动态动力学拆分促进N-保护氨基酸六氟异丙酯的碱水解反应，得到相应的产物，产率高达99%，产率高达96：4。实验和计算机制的研究，使用DFT计算和伪过渡态（伪TS）构象搜索提供了一个TS模型占的立体选择性的起源。该模型表明π堆积和氢键相互作用在稳定TS结构中起着重要作用。
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%) with up to 96:4 er. Experimental and computational mechanistic studies using DFT calculation and pseudotransition state (pseudo-TS) conformational search afforded a TS model accounting for the origin of the stereoselectivity. The model suggested π-stacking and H-bonding interactions play essential roles in stabilizing the TS structures.