The synthesis of enantiomerically pure compounds is a pivotal subject in the field of chemistry, with enantioselective catalysis currently standing as the primary approach for delivering specific enantiomers. Among these strategies, Cu-catalyzed asymmetric allylic substitution (AAS) is significant and irreplaceable, especially when it comes to the use of non-stabilized nucleophiles (pK_a > 25). Although Cu-catalyzed AAS of prochiral substrates has also been widely developed, methodologies involving racemic/meso substrates are highly desirable, as the substrates undergo dynamic processes to give single enantiomer products. Inspired by the pioneering work of the Alexakis, Feringa and Gennari groups, Cu-catalyzed AAS has been continuously employed in deracemization and desymmetrization processes for the synthesis of enantiomerically enriched products. In this review, we mainly focus on the developments of Cu-catalyzed AAS with racemic/meso substrates over the past two decades, providing an explicit outline of the ligands employed, the scope of nucleophiles, the underlying dynamic processes and their practical applications.

中文翻译：

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铜催化外消旋/内消旋底物的不对称烯丙基取代

对映体纯化合物的合成是化学领域的一个关键课题，对映选择性催化目前是提供特定对映体的主要方法。在这些策略中，铜催化的不对称烯丙基取代（AAS）是_重要且不可替代的，特别是在使用非稳定亲核试剂（p Ka > 25）时。尽管前手性底物的铜催化 AAS 也已得到广泛开发，但涉及外消旋/内消旋底物的方法是非常理想的，因为底物经历动态过程以产生单一对映体产物。受到 Alexakis、Feringa 和 Gennari 小组开创性工作的启发，Cu 催化 AAS 已持续用于合成对映体富集产品的去消旋和去对称过程。在这篇综述中，我们主要关注过去二十年来外消旋/内消旋底物铜催化原子吸收光谱的发展，提供了所使用的配体、亲核试剂的范围、潜在的动态过程及其实际应用的明确概述。