Mesoporous Carbons Functionalized with Aromatic, Aliphatic, and Cyclic Amines, and their Superior Catalytic Activity

A highly ordered mesoporous carbon has been successfully functionalized with various amino compounds including aliphatic, aromatic, and cyclic diamines via a simple C-N coupling process. The bonding between the carbon wall structure and the amino groups was confirmed by FT-IR, Raman, and X-ray photoelectron spectroscopy. The basicity of the materials can be tuned by simply changing the nature of the diamines on the carbon walls. The catalytic activity of the material as a solid base in the aza-Michael reaction of amines to activated alkenes was investigated. The functionalized materials were found to be highly active at room temperature and without any solvents, selective and can be recycled several times with consistent activity. The nature of the amine groups on the carbons significantly affects the formation of the -amino carbonyl compounds. Among functionalized carbons, carbon with aliphatic diamines showed the highest performance with a high yield of -amino carbonyl compounds.