Study On Catalytic Oxidation By The Diamines Synergetic Catalysis With TEMPO

The oxidation of alcohols to the corresponding alcohols or ketones is one of the most important transformations in organic synthesis, which plays an important role in organic synthesis and industrial fine chemical industry. In the recent years,realizing the by-product of the oxidation of oxygen and air is H20,which is friendly to the environment, so the molecular oxygen and air is the best oxidant which is rich,safe and cheap,so the researches which use molecular oxygen and air as oxidant for the catalyzed oxidation of alcohols to the corresponding alcohols or ketones is hot.We have made some useful research on the slectivite oxidation of alcohols oxidated by molecular oxygen and air in this paper.In recent years,2,2,6,6-Tetramethyl-piperidyl-l-oxyl (TEMPO) as a small molecular organocatalyst, has attracted more and more attention in a variety of free radical oxidation reaction of molecular oxygen. Currently, many literatures suggest that the oxidation of alcohols with TEMPO requires the aid of some cocatalysts. Furthermore, the compounds of diamines have high reactivity, and their structure can be regulated to a great extent,and their cost of production is low,and their synthesis is simple.so it is hopeful to be used as new models of catalytic oxidation systems of alcohols. So the studies on them have great theoretic significances and practical values.1.It was established a new catalytic system, which composed of2,2,6,6-Tetramethyl-piperidyl-l-oxyl(TEMPO) and the compounds of aliphatic diamines,which completed the aerobic oxidation of alcohols. It can be found that:(1) the compounds of diamines can markedly improve the catalytic activity of TEMPO and show good synergic catalytic action in the oxidation of alcohols;(2) We have studied the activity of N,N-dimethyl ethyl enediamines, N,N’-dimethyl-ethyl-enediamines and tetramethylethylenediamine and other diamines used to the oxidation of benzyl alcohol;(3) We used N,N’-dimethyl-ethylenediamines as template ligands and studied the effect of system N,N’-dimethyl-ethylenediamies/TEMPO/Cu in the oxidation of benzyl alcohol, which realized the aerobic oxidations of alcohols in the mild condition. This system use unpolluted water as solvent without any organic solvent or base, which realized truly environmental protection. In the presence of3mol%TEMPO,2mol%CuBr2and4mol%N,N’-dimethyl-ethylenediamies in10mL water,98%conversion of benzyl alcohol with99%selectivity for benzaldehyde can be obtained under the best oxidation conditions of reaction temperature80℃, reaction time4h,0.2MPa of dioxygen pressure.2.Five diamines copper complexes were synthesized and the structures of the target compounds were tested by IR, HNMR and element analysis. Their synergic catalytic actions in the oxidation of benzyl alcohol with TEMPO have been studied. It can be found that:(1) These complexes all have good effects on the oxidation of benzyl alcohol;(2) A varity of fators on the catalytic oxidations of benzyl alcohol were exmined. In the presence of3mol%TEMPO,1.5mol%copper complexes in6mL water,100%conversion of benzyl alcohol with99%selectivity for benzaldehyde can be obtained under the best oxidation conditions of room temperature, reaction time5h in the air.(3) This catalytic system got rid of the base, and also this catalytic system had high substrate universality.3.Paper provided a new way of integrationing TEMPO catalysts and cocatalyst, By4-carbonyl-TEMPO and N, N-dimethyl-ethylenediamine by reductive amination reaction got new catalyst with diamines compounds and nitrogen oxygen free radical. Based on the research of the advantage of the catalyst structure, which introduced help catalyst diamines groups in a matrix structure of TEMPO. Design and synthesize new coordination structure containing the TEMPO nitrogen oxygen free radical catalysts. Through this topic research, it found that by molecular oxygen for the antioxidant selective oxidation alcohol catalyst for single composition of high performance, which overcome problems of multicomposition catalytic oxidation system. It found that this type of catalyst mechanism and active change rule, which provide theoretical basis and technical support in research development green selective oxidation alcohol new technology.In summary, three new catalytic systems were established, and found the real green method on the catalytic oxidation of benzyl alcohol by efforts. They all displayed great performance in the catalytic aerobic oxidation of various alcohols, showing applicable potential.