Highly Enantioselective Three-Component Direct Mannich Reactions of Unfunctionalized Ketones Catalyzed by Bifunctional Organocatalysts
نویسندگان
چکیده
منابع مشابه
Pipecolic acid-catalyzed direct asymmetric mannich reactions.
Mannich reactions between aldehydes and N-p-methoxyphenyl-protected alpha-imino ethyl glyoxylate have been performed using (S)-pipecolic acid as catalyst. The reactions give both syn- and anti-products (dr=1.4-2:1) with high enantioselectivities (>98% ee). In contrast, (S)-proline-catalyzed reactions give mainly syn-products with high enantioselectivities. Computational studies reveal that the ...
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A series of pyrrolidine-based organocatalysts which bear three synergistic features, i.e. secondary amino group, various H-bond donor groups at the 4-position and a stereocontrol silyl ether group at the α-position of the pyrrolidine nitrogen atom, were developed. They were screened in anti-Mannich reactions of carbonyl compounds with preformed or in situ generated N-protected α-imino ethylglyo...
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The design, synthesis, and development of a new class of modular, strongly basic, and tunable bifunctional Brønsted base/H-bond-donor organocatalysts are reported. These catalysts incorporate a triaryliminophosphorane as the Brønsted basic moiety and are readily synthesized via a last step Staudinger reaction of a chiral organoazide and a triarylphosphine. Their application to the first general...
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A highly efficient diastereo- and enantioselective Mannich reaction of lactones with a variety of N-Boc-aldimines by using bifunctional rosin-derived amine thiourea catalysts was investigated for the first time, in general, affording the adducts bearing quaternary stereogenic centers with high levels of enantio- and diastereoselectivity (up to 99% ee, and >20:1 dr).
متن کاملSimple highly modular acyclic amine-catalyzed direct enantioselective addition of ketones to nitro-olefins.
Simple, highly modular primary amino acid derivatives catalyze the direct enantioselective addition of ketones to nitro-olefins with high stereocontrol and furnish the corresponding aldol products in high yield with up to >38 1 dr and up to 99% ee.
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ژورنال
عنوان ژورنال: Organic Letters
سال: 2013
ISSN: 1523-7060,1523-7052
DOI: 10.1021/ol303315c