Highly diastereoselective asymmetric Mannich reactions of 1,3-dicarbonyls with acyl imines.
نویسندگان
چکیده
[reaction: see text] The cinchona alkaloids catalyze direct asymmetric Mannich reactions of cyclic 1,3-dicarbonyl compounds with acyl imines to afford alpha-quaternary carbon-bearing reaction products in yields of up to 98%, a diastereomeric excess of 90% or greater, and enantioselectivities up to 99% ee. A model is proposed that accounts for both the observed diastereoselectivities and the enantioselectivities for the reactions.
منابع مشابه
Highly enantio- and diastereoselective Mannich reactions of glycine Schiff bases with in situ generated N-Boc-imines catalyzed by a cinchona alkaloid thiourea.
Highly enantio- and diastereoselective organocatalytic Mannich reactions of glycine Schiff bases with N-Boc-protected imines are described. Imines were generated in situ from bench-stable alpha-amido sulfones. Catalysis mediated by a cinchona alkaloid thiourea provided optically active alpha,beta-diamino acid derivatives with up to 99% ee and near-perfect diastereoselection.
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ورودعنوان ژورنال:
- Organic letters
دوره 8 10 شماره
صفحات -
تاریخ انتشار 2006