Copper dual-atom catalyst mediated C3–H amination of indoles at room temperature

Abstract

Direct and selective C–H bond functionalization has emerged as a promising alternative to avoid traditional wasteful and multi-step approaches. However, it is severely hampered by the low stability and low reusability of homogeneous catalysts. Herein, zeolite confined copper dual-atom catalysts were developed for C3–H amination of indoles with diarylamines. The catalytic transformation enabled the synthesis of a wide array of 3-diarylaminoindoles with the merits of mild reaction conditions, stable and reusable catalysts, excellent regio-selectivity, and operational simplicity. Hastened reactivity has been attributed to the synergistic cooperation between the neighboring copper active centers (for co-adsorption and co-activation) and the zeolitic framework (confined cavity) based on crystallographic evidence. Since no metal leaching has been noted, this warrants excellent further synthetic and commercial applications that allow direct access to a wide range of functional molecules. This work paves the way for further innovative organic synthesis over solid catalysts.