(1,2-Diaminoethane-1,2-diyl)bis(N-methylpyridinium) Salts as a Prospective Platform for Designing Recyclable Prolinamide-Based Organocatalysts

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• 作者：Vladislav G. Lisnyak ; Alexander S. Kucherenko ; Edward F. Valeev ; Sergei G. Zlotin
• 刊名：Journal of Organic Chemistry
• 出版年：2015
• 出版时间：October 2, 2015
• 年：2015
• 卷：80
• 期：19
• 页码：9570-9577
• 全文大小：522K
• ISSN：1520-6904

文摘

A new efficient and highly recyclable organocatalyst has been developed for asymmetric cross-aldol reactions under neat conditions in ketone鈥搆etone, ketone鈥揳ldehyde, and aldehyde鈥揳ldehyde systems. The catalyst features two prolinamide fragments and a C₂-symmetrical (1,2-diaminoethane-1,2-diyl)bis(N-methylpyridinium) group. The catalyst retained high activity and excellent stereoselection over the operating period of more than 830 h (25 cycles). An ab initio theoretical investigation explained the absolute configuration of the products and different stereoinduction levels for designed diastereomeric organocatalysts.