Highly active Co1-N3-O1 single-atom catalyst for boosting catalytic synthesis of unsaturated benzylamines and arylamines

Abstract

Unsaturated benzylamines and arylamines are the key building blocks for the synthesis of organic pharmaceutical molecules, but their synthetic processes always suffer from low selectivity as a result of the excessive hydrogenation of unsaturated groups. Herein, the cobalt single-atom catalyst with an asymmetric Co1-N3-O1 structure was designed and constructed on porous carbon nanospheres. It is found that the Co1-N3-O1 catalyst showed excellent catalytic activity toward the synthesis of unsaturated benzylamines and arylamines. The results of characterization analysis and density functional theory (DFT) calculation further clarify that introducing oxygen into the Co single-atom coordination environment of Co1-N3-O1 increased hydrogenation energy barrier of the terminal C=C double bond, which is beneficial to suppress competing hydrogenation reactions. Meanwhile, the Co1-N3-O1 catalyst had the lower energy barrier for reduction of the C=N bond to amino group, boosting the yields of unsaturated benzylamines and arylamines. This study offers an attracting strategy for efficient and selective reductive amination reaction by making use of the asymmetrically structured Co single-atom catalyst.