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采用密度泛函理论(DFT)中的B3LYP方法,在B3LYP/6-31+G(d,p)基组水平上(In采用赝势基组Lan L2DZ),二氯乙烷(DCE)作为溶剂,研究了In X_3(X=F,Br)催化N-甲基吲哚与酮酸酯不对称合成微观反应机理,对反应通道上反应物、中间体、过渡态和产物进行了结构优化,通过能量和振动频率分析以及内禀反应坐标(IRC)计算证实了过渡态和中间体的合理性,并且在相同基组水平上,通过自然键轨道(NBO)理论和原子理论(AIM)分析了分子轨道间的相互作用及成键特点.结果发现:在In F_3催化作用下,N-甲基吲哚与酮酸酯反应形成1,2-加成产物和1,4-加成产物的反应速控步骤活化能分别为25.62和12.52 kcal/mol,在In Br_3催化作用下,N-甲基吲哚与酮酸酯反应形成1,2-加成产物和1,4-加成产物的反应速控步骤活化能分别为26.87和13.95 kcal/mol.比较研究结果,In F_3能有效催化该反应的进行,且1,4-加成产物更容易生成,我们的研究结果与实验结果相吻合.还采用连续介质模型(PCM)比较了5种溶剂化作用对反应的影响,可以预测:二甲亚砜(DMSO)溶剂条件下,In F3催化1,4-加成产物的产率会更高.
Using the B3LYP method in density functional theory (DFT), DLC was used as the solvent at B3LYP / 6-31 + G (d, p) basis group level , The reaction mechanism of asymmetric synthesis of N-methylindole and keto acid ester catalyzed by In X_3 (X = F, Br) was studied. The structures of reactants, intermediates, transition states and products on the reaction channel were optimized. Energy and vibrational frequency analysis and intrinsic reaction coordinate (IRC) calculations confirm the rationality of the transition states and intermediates, and at the same basis set level, molecules are analyzed by the theory of natural bond orbital (NBO) and atom theory (AIM) Orbitals and the formation of bonds.It was found that the reaction rate of N-methylindole reacted with ketoacid ester to form 1,2-adduct and 1,4-adduct catalyzed by In F 3 The activation energies of the control steps are 25.62 and 12.52 kcal / mol, respectively. Under the reaction of In Br_3, the reaction rate between N-methylindole and ketoacid ester to form 1,2-adduct and 1,4-adduct The activation energies of the control steps were 26.87 and 13.95 kcal / mol, respectively.Compared with the results, In F 3 could effectively catalyze the reaction and the 1,4-addition product was easier to generate. The results are in good agreement with the experimental results.The effects of five solvating reactions on the reaction were also compared using a continuous media model (PCM), and it was predicted that in In dimethylsulfoxide (DMSO) solvent, The yield of the product will be higher.