Calcined CaAl LDH Nanoplates as a Highly Active Heterogeneous Catalyst for Efficient N‐Formylation of Amines

Abstract This work presents the synthesis of CaAl layered double hydroxide nanoplates (CaAl‐LDH) using a hydrothermal method, calcined at 550°C. The obtained samples were characterized by XRD, FTIR, FE‐SEM, and BET. Destruction of the layered structure in CaAl‐LDH and formation of CaAl‐layered double oxide (CaAl‐LDO) were confirmed by XRD and FTIR techniques. Nanoplates of CaAl‐LDH and CaAl‐LDO were optimized to catalyze N‐formylation of aniline by using formic acid under solvent‐free conditions. The reaction showed a conversion of 35% with CaAl‐LDH nanoplates, while in the presence of the CaAl‐LDO nanoplates, a conversion of 80% was observed. Thus, the CaAl‐LDO nanocatalyst was selected for the chemoselective transformation of various amines to the corresponding formamides as the sole product (average reaction time: 21 min; average conversion: 90%; average TOF: 0.88 min −1 ). The catalyst was reused for up to five runs without a significant decrease in the catalyst activity. The simple experiment procedure, cost‐efficient, short reaction times, and good chemoselectivity are the most important advantages of this catalytic system.