College of Pharmacy, International Scientific and Technological Cooperation Base of Chiral Chemistry, Henan University, Kaifeng, Henan, 475004, P. R. China.
School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007, P. R. China.
Angew Chem Int Ed Engl. 2022 Dec 5;61(49):e202211241. doi: 10.1002/anie.202211241. Epub 2022 Nov 9.
Catalytic deracemization is an ideal synthetic strategy due to its formally perfect atom utilization. Asymmetric photocatalysis has been appreciated as a promising tool to accomplish this attractive reaction pattern in an economical fashion, but it remains underdeveloped. Here, we report a new platform based on photoredox-neutral catalysis, allowing efficient and modular optical enrichment of α-amino esters and other valuable analogues. Two single-electron transfer processes between the photocatalyst and the substrates serve to provide the key prochiral intermediates, and the chiral Brønsted acid catalyst mediates enantioselective protonation to reconstitute a stereogenic C-H bond. The efficiency of deracemization is determined by the enantiofacial differentiation effect during the stereocentre-forming step.
催化外消旋化是一种理想的合成策略，因为它在形式上实现了完美的原子利用率。不对称光催化被认为是一种很有前途的工具，可以经济高效地实现这种吸引人的反应模式，但它仍在发展中。在这里，我们报告了一种基于光氧化还原中性催化的新平台，允许高效和模块化的光学富集α-氨基酯和其他有价值的类似物。光催化剂和底物之间的两个单电子转移过程用于提供关键的前手性中间体，而手性布朗斯台德酸催化剂介导对映选择性质子化，以重新构建手性 C-H 键。外消旋化的效率取决于形成立体中心步骤中的对映面差异效应。
