351387-13-8Relevant academic research and scientific papers
Aerobic oxidative coupling of alcohols and amines to imines over iron catalysts supported on mesoporous carbon
Geng, Longlong,Song, Jinling,Zheng, Bin,Wu, Shujie,Zhang, Wenxiang,Jia, Mingjun,Liu, Gang
, p. 1451 - 1460 (2016)
Direct oxidative coupling of an alcohol and amine, with air or molecular oxygen as the oxygen source, is an environmentally friendly method for imine synthesis. We developed an Fe catalyst supported on mesoporous carbon (denoted by FeOx/HCMK-3) for this reaction with excellent activity and recyclability. FeOx/HCMK-3 was prepared by impregnating HNO3-treated mesoporous carbon (CMK-3) with iron nitrate solution. The highly dispersed FeOx species give FeOx/HCMK-3 high reducibility and are responsible for the high catalytic performance. Imine synthesis over FeOx/HCMK-3 follows a redox mechanism. The oxygen species in FeOx/HCMK-3 participate in the reaction and are then regenerated by oxidation with molecular O2. The reaction involves two consecutive steps: oxidative dehydrogenation of an alcohol to an aldehyde and coupling of the aldehyde with an amine to give an imine. Oxidative dehydrogenation of the alcohol is the rate-determining step in the reaction.
A bifunctional PdVMgO solid catalyst for the one-pot selective N-monoalkylation of amines with alcohols
Corma, Avelino,Rodenas, Tania,Sabater, Maria J.
supporting information; experimental part, p. 254 - 260 (2010/03/26)
It has been found that a bifunctional metal Pd/base (MgO) catalyst performs the selective monoalkylation of amines with alcohols. The reaction goes through a series of consecutive steps in a cascade mode that involves: 1) the abstraction of hydrogen from the alcohol that produces the metal hydride and the carbonyl compound; 2) condensation of the carbonyl with the amine to give an imine, and 3) hydrogenation of the imine with the surface hydrogen atoms from the metal hydride. Based on isotopic and spectroscopic studies and on the rate of each elementary step, a global reaction mechanism has been proposed. The controlling step of the process is the hydride transfer from the metal to the imine. By changing the crystallite size of the Pd, it is demonstrated that this is a structure-sensitive reaction, whereas the competing processes that lead to subproducts are not. On these bases, a highly selective catalyst has been obtained with Pd crystallite size below 2.5 nm in diameter. The high efficiency of the catalytic system has allowed us to extend the process to the one-pot synthesis of piperazines.
