Affiliation:
1. Pingyuan Laboratory School of Chemistry and Chemical Engineering Henan Normal University Xinxiang Henan P. R. China 453007
2. Henan Key Laboratory of Natural Medicine Innovation and Transformation Henan University Kaifeng Henan P. R. China 475004
3. College of Advanced Interdisciplinary Science and Technology Henan University of Technology Zhengzhou Henan, P. R. China 451001
Abstract
AbstractVisible light‐driven photocatalytic deracemization is highly esteemed as an ideal tool for organic synthesis due to its exceptional atom economy and synthetic efficiency. Consequently, successful instances of deracemization of allenes have been established, where the activated energy of photosensitizer should surpass that of the substrates, representing an intrinsic requirement. Accordingly, this method is not applicable for axially chiral molecules with significantly high triplet energies. In this study, we present a photoredox catalytic deracemization approach that enables the efficient synthesis of valuable yet challenging‐to‐access axially chiral 2‐azaarene‐functionalized quinazolinones. The substrate scope is extensive, allowing for both 3‐axis and unmet 1‐axis assembly through facile oxidation of diverse central chiral 2,3‐dihydroquinazolin‐4(1H)‐ones that can be easily prepared and achieve enantiomer enrichment via deracemization. Mechanistic studies reveal the importance of photosensitizer selection in attaining excellent chemoselectivity and highlight the indispensability of a chiral Brønsted acid in enabling highly enantioselective protonation to accomplish efficient deracemization.