Tan Jiuqi, Yang Longqing, Su Hanyu, Yang Yuntian, Zhong Ziwei, Feng Xiaoming, Liu Xiaohua
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 P. R. China
Chem Sci. 2024 Sep 16;15(39):16050-8. doi: 10.1039/d4sc04900d.
Visible-light-driven direct asymmetric α-C(sp)-H bond functionalization of glycinate provides a direct and efficient route for the synthesis of diverse optically enriched α-amino acid derivatives. However, asymmetric coupling between glycinate radical species and ketones faces significant challenges, including competitive pathways, mutable intermediates, as well as congested stereogenic centers. Herein, we disclose the first example for the asymmetric photocatalytic synthesis of a diverse array of β-diaryl-β-hydroxy-α-amino acetate derivatives from glycinates and heteroaryl ketones through the synergistic catalysis of achiral iridium photoredox catalyst and chiral lanthanide Lewis acid catalysts. The enantioselective radical addition pathway is supported by spectroscopic experiments, control experiments and DFT calculations.
可见光驱动的甘氨酸酯直接不对称α-C(sp)-H键官能团化反应为合成多种光学富集的α-氨基酸衍生物提供了一条直接而有效的途径。然而,甘氨酸酯自由基物种与酮之间的不对称偶联面临着重大挑战,包括竞争途径、可变中间体以及拥挤的手性中心。在此,我们报道了首例通过非手性铱光氧化还原催化剂和手性镧系路易斯酸催化剂的协同催化,从甘氨酸酯和杂芳基酮不对称光催化合成多种β-二芳基-β-羟基-α-氨基乙酸酯衍生物的实例。光谱实验、对照实验和密度泛函理论计算支持了对映选择性自由基加成途径。