The 3d metals have been identified as economic and sustainable alternatives to palladium, the frequently used metal in transition-metal-catalysed cross-couplings. However, cobalt has long stood behind its neighbouring elements, nickel and copper, in asymmetric radical couplings owing to its high catalytic activity in the absence of ligands resulting in unfavourable un-asymmetric background reactions. Here we disclose an asymmetric metallaphotoredox catalysis (AMPC) strategy for the dynamic kinetic asymmetric transformation of racemic heterobiaryls, which represents a visible-light-induced, asymmetric radical coupling for the construction of axial chirality. This success can also be extended to the reductive cross-coupling variant featuring the use of more easily available organic halide feedstocks. The keys to these achievements are the rational design of a sustainable AMPC system that merges asymmetric cobalt catalysis with organic photoredox catalysis in combination with the identification of an efficient chiral polydentate ligand.

3天金属已被确定为钯的经济和可持续替代品，钯是过渡金属催化交叉偶联中常用的金属。然而，由于钴在没有配体的情况下具有高催化活性，导致不利的不对称背景反应，因此钴长期以来一直落后于其相邻元素镍和铜。在这里，我们公开了一种不对称金属光氧化还原催化 (AMPC) 策略，用于外消旋杂二芳基的动态动力学不对称转化，它代表了一种可见光诱导的不对称自由基偶联，用于构建轴向手性。这一成功也可以扩展到还原交叉偶联变体，其特点是使用更容易获得的有机卤化物原料。