Advances in nickel-catalyzed cross-coupling reactions have expanded the chemical space of accessible structures and enabled new synthetic disconnections. The unique properties of Ni catalysts facilitate the activation of traditionally inert substrates, tolerate alkyl coupling partners that undergo decomposition via β-hydride (β-H) elimination with Pd, and enable stereoconvergent cross-couplings. The radical pathways accessed by Ni catalysts have been merged with photoredox and electrochemical catalysis to achieve new reactivity. The growing utility of Ni catalysis is, in no small part, due to advances in our fundamental understanding of the properties of Ni catalysts and the mechanisms by which the reactions occur. This review highlights recent important contributions to the field with an emphasis on studies that have afforded mechanistic insight.

镍催化交叉偶联反应的进展扩大了可及结构的化学空间，并实现了新的合成断开连接。Ni催化剂的独特性能促进了传统惰性底物的活化，可耐受通过Pd消除β-氢化物（β-H）进行分解的烷基偶联伙伴，并实现立体会聚交叉偶联。Ni催化剂访问的自由基途径已与光氧化还原和电化学催化合并，以实现新的反应性。镍催化作用的日益增长，很大程度上是由于我们对镍催化剂的性质以及反应发生机理的基本理解方面的进展。这篇综述着重介绍了最近对该领域的重要贡献，重点是提供了机械学见解的研究。