Palladium-catalyzed three-component reaction of N-tosyl hydrazones, isonitriles and amines leading to amidines
作者:Qiang Dai、Yan Jiang、Jin-Tao Yu、Jiang Cheng
DOI:10.1039/c5cc06771e
日期:——
A palladium-catalyzed three-component reaction between N-tosyl hydrazones, aryl isonitriles and amines was developed, leading to amidines in moderate to good yields.
Kinetic studies for amination of ketenimines: change of rate-determining step by electron-withdrawing N-substituents through electronic effects
作者:Kuangsen Sung、Pin-Mei Huang、Shu-Min Chiang
DOI:10.1016/j.tet.2006.03.022
日期:2006.5
to Kk2 for the amination of 1a–d and the Hammett plot was a convex curve with ρD=ρ1=7.08 and ρA=ρK+ρ2=0.98, indicating change of the rate-determining step. The electron-withdrawing para-substituents on the N-phenyl group of ketenimines significantly stabilize the first transition state of CN addition, resulting in change of the rate-determining step to the second step of tautomerization. The N-substituent
NMR and ab Initio Studies of Amination of Ketenimine: Direct Evidence for a Mechanism Involving a Vinylidenediamine as an Intermediate
作者:Kuangsen Sung、Shu-Hwa Wu、Ru-Rong Wu、Shu-Yi Sun
DOI:10.1021/jo025523z
日期:2002.6.1
High-level abinitio calculations were carried out in both gas phase and solvent (epsilon = 35.9) to estabilish that the amination of ketenimine proceeds via amine addition across the C=N bond rather than the C=C bond, followed by tautomerization to form amidine product. The HOMO of ketenimine is perpendicular to its molecular plane with the largest coefficient on C(beta), while the LUMO is in its
is changed from the first step (CN addition) to the second step (tautomerization) when N-substituent of the ketenimines is changed from i-propyl group to p-substituted-phenyl group. Amination reactions of ketenimines 5 and 10 in a solvent with ε=35.9 were designed to explore electronic effects of N-substituents on the amination reactions by means of ab initio calculations. Computation results at level
Vinylidenediamine化的中间产物在胺化反应中发现ñ -我丙基p取代-phenylketenimines 3A -图3e与Ñ -BuNH 2,但它在的胺化反应中发现ñ - p -取代-phenylphenylketenimines 1A - 1C与ñ -低温1 H NMR光谱仪检测BuNH 2,表明当烯酮亚胺的N取代基从i改变时,速率确定步骤从第一步(CN加成)改变到第二步(互变异构)。-丙基至对-取代苯基。设计了在ε = 35.9的溶剂中的酮亚胺5和10的胺化反应,以通过从头算来探索N-取代基对胺化反应的电子影响。在MP2 / 6-31 + G * // HF / 6-31 + G *的水平上的计算结果(Onsager模型)表明,涉及由N-苯基加成CN的第一过渡态的显着电子稳定是导致改变胺化反应的速率决定步骤。