| The Knoevenagel condensation reaction of aromatic aldehydes with malonotrile is an important method for forming C-C bond, which has been studied extensively and applied in many organic syntheses. The condensation products of the condensation reaction are the charge t ransfer c omplexes t hat c an b e u sed as functional m aterial, a nd t here h as b een a steady growth of interest in this area. A lot of the Knoevenagel condensation reactions have been studied in the 20th century and recently, but the study of reaction is separate and isolated, there are only a few references about the catalysts. To the best of our knowledge, we have not found any report of systemic study about the catalyst-effect in the Knoevenagel condensation and any study of quantum chemistry about mechanism of the reaction. The study of reaction mechanism is important to learn of reaction track and understand the catalyst effect of the reaction. If the reaction mechanism is known, the reaction can be controlled and found the better catalyst. So the Knoevenagel condensation reactions o f a romatic a Idehydes w ith m alonotrile h ave b een s tudied b y experiments a nd quantum chemical computations in this thesis, the major work is as following.l.The experimental studies of the Knoevenagel condensation reaction of aromatic aldehydes with malonotrileThe methods of solid-state synthesis are new green synthetical methods, which are extensively applied in many reactions. There are mang advantage about method of solid-state synthesis, such as free solvent, easy operation, few subsidiary reactions and so on. Solid-state synthesis has been used to the Knoevenagel Condensation reaction of aromatic aldehydes with malonotrile in this thesis, and the experimental work has two major aspects.(1) Using different catalystThe Knoevenagel condensation reaction of 4-NO2-PhCHO with CftyCNh have been studied in details using different catalysts and discussed the rule of catalyst-effect in this thesis.Our work includes two parts. One is the catalyst-effect of different catalysts that have the same anion and different cations; the second is the catalyst-effect of different catalysts that have the same cation and different anions. The experimental result showed that catalyst-effect of catalyst NH4Ac is the best among all catalysts we have studied.(2) The experimental etudies of the Knoevenagel condensation of different aromatic aldehydes with malonotrile using same catalystWe studied the Knoevenagel condensation reaction of different aromatic aldehydes withmalonotrile in details using the same catalyst (NHUAc). The experimental result indicated that reaction activity of 4-NO2-PhCHO is best, 4-OH-PhCHO is worst.2. The theoretical studies of the Rnoevenagel condensation reaction of aromatic aldehydes with malonotrileThe density functional theory (DFT) AT B3LYP/6-31G* level and semi-empirical AMI method have been employed to study mechanism of the Knoevenagel condensation reaction of aromatic aldehydes with malonotrile. The geometries of reactors, products and transition states of the reaction have been optimized, and active energies of the reactions have been obtained. The potential profile for every reaction was studied by using the calculations of IRC. The results are very useful for understanding the mechanism of the Knoevenagel condensation reaction. The major work we have done is as following.(1) Mechanism of the reaction of formaldehyde with malonotrileThe mechanism of the reaction of formaldehyde with malonotrile has been studied under three different conditions, one is the condition of no catalyst, the second is the condition with HX (X=C1, Br) as catalysts and the third is the condition with catalysts of NaX (X=C1, Br). The results of DFT at B3LYP/6-31G* computations indicated that the catalyst-effect of NaBr is the best among the catalysts we studied here.(2) Theoretical studies of the reactions of aromatic aldehydes with malonotrileThe essential of reaction of aromatic aldehydes with malonotrile is the same as the reaction of formald... |
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