N-alkyl amines are important chemical intermediates and are mainly produced by N-alkylation of amines. To develop new green method and highly efficient catalytic materials for the N-alkylation reactions have been the focus in the field.  

The group headed by Prof. SHI Feng at the Lanzhou Institute of Chemical Physics (LICP) of the Chinese Academy of Sciences (CAS) has been engaged in the study of heterogeneous catalysts for N-alkyl amine synthesis since 2009. Recently, based on their previous work on preparation of heterogeneous catalysts including supported nano-Pd, Ag and Au, etc. (Chem. Commun.,2014, 50, 13521-13523; ChemSusChem., 2014, 7, 720-722; ACS Catal., 2013, 3, 808-811; Chem. Eur. J.,2013, 19, 3665-3675; Chem. Commun., 2012, 48, 7586-7588; 2012, 48, 9391-9393; 2011, 47, 6476-6478; Chem. Eur. J. 2011, 17, 1021-1028; 2011, 17, 2587-2591), the group has prepared a series of new catalysts and successfully applied them in N-alkyl amine synthesis. 

Firstly, they have designed and prepared an efficient nickel-copper hybrid catalytic material for the synthesis of N-alkyl amine via alcohol amination without the addition of noble metal and organic ligand. This novel catalyst is stable to air and moisture, and can be re-covered from the reaction mixture and reused easily. The researchers have received an American invention patent for the technique. (US8901354 B2, by SHI Feng, CUI Xinjiang, YUAN Hangkong and DENG Youquan).  

In order to promote the recycling of CO₂ in fine chemical synthesis, the group has prepared CuAlOx and supported nano-Pd catalysts for the one-pot synthesis of N-methyl, N,N-dimethyl and N-formamide amines with CO₂/H₂ as the methyl and carbonyl source. The starting materials can be extended to nitrobenzene derivatives and aromatic nitriles (Chem. Sci., 2014, 5, 649-656; Chem. Commun., 2012, 50, 189-191; 13521-13523). Concerning the new method and catalysts, the researchers have applied both Chinese and American patents.  

In previous reports about N-alkyl amine synthesis, the catalysts are mainly composed of transition-metals rather than heterogeneous non-transition-metals. Through extensive studies, the group has developed a simple and efficient nano-carbon catalyst for the N-alkyl amine synthesis via alcohol amination reaction. This catalytic material exhibits excellent performance in the borrowing-hydrogen reactions including alcohol amination and catalytic reduction of nitro- and carbonyl groups. The work was published online at Nature Communications(2015, 6,6478,  doi: 10.1038/ncomms7478) . 

Image by SHI Feng et al.