Metallaphotocatalytic Amination of Aryl Chlorides Enabled by Highly Crystalline Acetylene‐Based Hydrazone‐Linked Covalent Organic Frameworks

Amination of aryl chlorides by metallaphotocatalysis is highly desired but remains practically challenging. Meanwhile, relying on soluble noble‐metal photocatalysts suffers from resource scarcity and structural instability which limit their practical application. Here in, a highly crystalline acetylene‐based hydrazone‐linked covalent organic framewok‐1 (AC‐COF‐1) is reported that enables metallaphotocatalytic amination of aryl chlorides. The non‐planar effect of hydrazone linkage and weak interlayer attraction of acetylene bond are minimized by intralayer hydrogen‐bonding. As a result, the COF shows not only improved crystallinity and porosity, but also enhanced optical and electronic properties compared to a COF analog without hydrogen‐bonding. Notably, dual AC‐COF‐1/Ni system affords CN coupling products from broad aryl chloride substrates in excellent yields (up to 99%) and good functional tolerance. Furthermore, AC‐COF‐1 is recoverable and reusable for seven times photocatalysis cycles. This report demonstrates simple approach to tune the structure‐activity relationship in COFs at molecular level. An acetylene‐based hydrazone‐linked covalent organic framework is prepared as promising recyclable photocatalyst for metallaphotocatalytic amination of aryl chlorides in the presence of inexpensive Ni salt catalyst. A strategy by imparting Intralayer H‐bonding improves the structural qualities and optoelectronic properties that lead to the enhanced photocatalytic performances. The reported findings pave the development of photocatalyst‐based COF materials.