کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
63407 | 47686 | 2006 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
An unexpected inversion of enantioselectivity in direct asymmetric aldol reactions on a unique L-proline/γ-Al2O3 catalyst
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
مهندسی شیمی
کاتالیزور
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چکیده انگلیسی
L-proline adsorbed on γ-Al2O3 unexpectedly switches the enantioselectivity of the direct asymmetric aldol reaction of acetone with p-nitrobenzaldehyde from 68% ee (R configuration for free L-proline catalyst) with 80% yield to 21% ee (S configuration) with 78% yield. The inversion of enantioselectivity was also observed in the direct asymmetric aldol reactions of acetone with several other aromatic aldehydes catalyzed by the L-proline adsorbed on γ-Al2O3. This inversion phenomenon is found to be general for different types of amino acids adsorbed on γ-Al2O3. The hydroxyl groups on γ-Al2O3 are found to be involved in the inversion induction of enantioselectivity in these direct asymmetric aldol reactions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Catalysis - Volume 243, Issue 2, 25 October 2006, Pages 442–445
Journal: Journal of Catalysis - Volume 243, Issue 2, 25 October 2006, Pages 442–445
نویسندگان
Lin Zhong, Jianliang Xiao, Can Li,