Ni-Doped Perovskite for Photocatalytic Benzylic C-H Amination

Directly introducing aliphatic or aromatic amines into C(sp³)-H bonds remains a significant challenge in organic synthesis. One major difficulty is that C(sp³)-H activation is an oxidative process, whereas amines are generally more prone to oxidation than C-H bonds, making them difficult to use directly. Typically, protected amines are employed and then deprotected to realize amination, but this strategy limits the synthesis of tertiary amines, as protected secondary amines are often inactive in such reactions. Here, we present a mild photocatalytic method that overcomes these limitations by utilizing Ni-doped perovskite CsPbBr₃ nanocrystals (NCs) for benzylic C-H amination directly using unprotected aliphatic or aromatic amines. Perovskite enables highly selective C-H activation, while doped Ni(II) readily captures benzylic radicals via oxidative addition. XPS studies successfully validate such an oxidative addition step with a Ni(II)/Ni(III) configuration. Our methodology forges aromatic and aliphatic, cyclic and acyclic, and secondary and tertiary amines and provides a powerful tool for the late-stage functionalization of bioactive compounds and drug derivatives.