Creating, conserving and modifying the stereochemistry of organic compounds has been the subject of significant research efforts in synthetic chemistry. Most synthetic routes are designed according to the stereoselectivity-determining step. Stereochemical editing is an alternative strategy, wherein the chiral-defining or geometry-defining steps are independent of the construction of the major scaffold or complexity. It enables late-stage alterations of stereochemistry and can generate isomers from a single compound. However, in many instances, stereochemical editing processes are contra-thermodynamic, meaning the transformation is unfavourable. To overcome this barrier, photocatalysis uses photogenerated radical species and introduces thermochemical biases. A range of synthetically valuable contra-thermodynamic stereochemical editing processes have been invented, including deracemization of chiral molecules, positional alkene isomerization and dynamic epimerization of sugars and diols. In this Review, we highlight the fundamental mechanisms of visible-light photocatalysis and the general reactivity modes of the photogenerated radical intermediates towards contra-thermodynamic stereochemical editing processes.

创建、保存和修改有机化合物的立体化学一直是合成化学中重要研究工作的主题。大多数合成路线是根据立体选择性决定步骤设计的。立体化学编辑是一种替代策略，其中手性定义或几何定义步骤独立于主要支架的构造或复杂性。它使立体化学的后期改变成为可能，并且可以从单一化合物中生成异构体。然而，在许多情况下，立体化学编辑过程是逆热力学的，这意味着转换是不利的。为了克服这一障碍，光催化使用光生自由基物质并引入热化学偏差。已经发明了一系列具有综合价值的逆热力学立体化学编辑过程，包括手性分子的去外消旋化、位置烯烃异构化以及糖和二醇的动态差向异构化。在这篇综述中，我们重点介绍了可见光光催化的基本机制和光生自由基中间体对逆热力学立体化学编辑过程的一般反应模式。