کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5418720 | 1506968 | 2007 | 8 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Theoretical study of the cyclization of carbonyl groups on unactivated alkynyl-quinolines in the gas phase and in methanol solution
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
We have performed a detailed study of the cyclization of carbonyl groups on unactivated alkynyl-quinolines. Two cyclization modes are accessible: the exo vs. endo mode. The influence of the substituents of the alkynyl-quinolines have been studied using two examples giving different reactivity: the phenyl and the CH2OMe substituent. From an experimental point of view, the reaction occurs in basic medium and the first step of the reaction has been shown to be the formation of the hemi-acetal. Two mechanisms have been investigated with and without deprotonation of the hemi-acetal prior to the carbon-oxygen bond formation and the proton's transfer. The influence of the solvent effects has been studied using supermolecular and continuum/supermolecular techniques. The mechanism without deprotonation of the hemi-acetal presents high barriers and the inclusion of solvent effects both with the continuum method and the supermolecular approach stresses strongly this tendency especially when phenyl substituents are used. On the other hand, the base mechanism exhibits lower barriers but solvent effects also increase these barriers, which remain quite reasonable around 15 kcal molâ1. Whatever the methods used, the exo mode of reaction appears to be the kinetic pathway whereas the endo mode appears to be under thermodynamic control.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure: THEOCHEM - Volume 811, Issues 1â3, 1 June 2007, Pages 175-182
Journal: Journal of Molecular Structure: THEOCHEM - Volume 811, Issues 1â3, 1 June 2007, Pages 175-182
نویسندگان
Carine Michel, Thomas Godet, Marie-Louise Dheu-Andries, Philippe Belmont, Anne Milet,