C-H bond cyanation of arenes using N,N-dimethylformamide and NH4HCO3 as a CN source over a hydroxyapatite supported copper catalyst

A hydroxyapatite supported Cu catalyst [HAP:Ca-5(PO4)(3)(OH)] has been found to be an efficient and reusable heterogeneous catalyst for safe cyanation of C-H bonds of hetero aryl compounds. The combination of NH4HCO3 and DMF is identified as a CN source under mild reaction conditions. 10 wt% Cu/HAP offered good to excellent yields compared to Ru/HAP and Pd/HAP catalysts. The surface basicity and Cu metal surface area of the catalysts played a significant role in the cyanation reaction through C-H bond activation. The catalyst was recovered and reused for five cycles showing consistent activity and selectivity. The physicochemical characteristics of the catalysts are rationalized by H-2-TPR, BET-SA, XPS, TEM and N2O titration techniques.