In this paper, we report a new mild and environmentally friendly approach for the direct C–N coupling of aromatic aldehydes with amines at room temperature to synthesize amides in which H2O2 serves as the oxidizing agent without the need for a catalyst. Investigation into substrate scope showed that the strategy exhibits good functional group tolerance. Under the optimal reaction conditions, the direct C–N coupling of aromatic aldehydes with secondary amines affords a series of amide products with moderate to high yields of 67%–95%, along with the sole byproduct of water. Additionally, a maximum isolated yield of 90% is achieved in the gram-scale reaction. Finally, a plausible reaction mechanism is proposed via a series of parallel experiments.
Zhao et al. (Tue,) studied this question.