Amine alcohol alkylation reaction is one of the main methods for the clean preparation of N-alkylated amines. However, catalyst systems with high activity, high selectivity and excellent universality for the alkylation of amine alcohols are mainly concentrated in homogeneous catalysts of precious metals, and many non-noble metals with excellent performance and universality for the alkylation of amine alcohols There are few reports of phase catalyst systems.
Based on the successful realization of the preparation of N-alkylated amine based on heterogeneous catalysts of palladium, silver, gold and other precious metals (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; Tetrahedron Lett., 2011, 52, 1334–1338; 2010, 51, 2048–2051), Chinese Academy of Sciences Researchers at the Green Chemistry and Catalysis Center of the Lanzhou Institute of Chemical Physics designed and prepared a simple nickel-copper hybrid material catalyst. Without the use of precious metals and organic ligands, the preparation of primary amines by alkylation of amine alcohols Secondary amines, quaternary amines and cyclic amines. The catalyst is insensitive to air and water and has good magnetic properties, making it easy to separate from the reaction mixture. The catalyst can be reused many times without significant deactivation. The research work was published as Back Cover in Chem. Eur. J. (2013, 19, 3665 – 3675) and was selected as the VIP paper. Relevant results have applied for Chinese invention patents and US patents (application number .7; 13 / 729,664).
Gold nanocatalysts exhibit good catalytic performance in the low-temperature oxidation of carbon monoxide, which is one of the hot spots in the field of catalytic chemistry. Recently, the Green Chemistry and Catalysis Center of Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences has made new progress in the controllable preparation of nano-gold catalysts.
It is generally believed that the removal of chloride ions by washing in the preparation of nano-gold catalysts is one of the key operations for obtaining highly active nano-gold catalysts. However, the research work found that excessive washing when removing chloride ions is one of the possible reasons for the uncontrollable preparation of highly active gold catalysts. Taking carbon monoxide oxidation and nitrobenzene reductive alkylation as examples, when the concentration of chloride ion in the aqueous solution of the catalyst precursor is ~ 2 ppm, a highly active gold nanocatalyst can be prepared when the concentration of chloride ion is> 4–6 or << The activity of the prepared catalyst drops sharply at 1 ppm. The reason why the catalyst activity drops sharply when the chloride ion concentration is << 1 ppm may be caused by excessive washing or excessive removal of chloride ion. Characterization found that the structure of the highly active catalyst is nano-gold particles supported on the edges / ribs of iron oxide particles, and the coordination number of gold is 8.92. Although no evidence has been found that chloride ion participates in the construction of the active structure of the nano-gold catalyst, this result provides a new idea for the controllable preparation of the highly active nano-gold catalyst. Related research work was published in Sci. Rep., (2013, 3, 1503).
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