Sterically Congested Chiral N-Acetyl 2-Oxazolidinone as Acetyl Enolate Equivalents in Stereoselective Aldol Reactions.
نویسندگان
چکیده
منابع مشابه
Stereoselective Acetate Aldol Reactions
The stereochemical control of aldol reactions from unsubstituted enolor enolatelike species, what are known as acetate aldol reactions, has been a matter of concern for nearly 30 years [1, 2]. Indeed, pioneering studies soon recognized that the asymmetric installation of a single stereocenter in such aldol reactions was much more demanding than the simultaneous construction of two new stereocen...
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The catalytic generation of chiral ester enolate equivalents from α,β-unsaturated aldehydes with chiral N-hetereocyclic carbene catalysts makes possible highly enantioselective hetero-Diels– Alder reactions. The reactions proceed under simple, mild conditions with both aliphatic and aromatic substituted enals as substrates. Previous attempts to employ these starting materials as enolate precurs...
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[reaction: see text] Diastereoselective direct aldol reactions of chiral N-acylthiazolidinethiones occur in high yield with preference for the illustrated anti diastereomer. This reaction is catalyzed by 10% MgBr2.OEt2 in the presence of triethylamine and chlorotrimethylsilane. Yields range from 56 to 93% with diastereoselectivity up to 19:1 for a variety of N-acylthiazolidinethiones and unsatu...
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In a systematic study of molecular recognition of amino acid derivatives in solid-state β-cyclodextrin (β-CD) complexes, we have determined crystal structures for complexes of β-cyclodextrin/N-acetyl-L-phenylalanine at 298 and 20 K and for N-acetyl-D-phenylalanine at 298 K. The crystal structures for the N-acetyl-L-phenylalanine complex present disordered inclusion complexes for which the distr...
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As an extension of the boron enolate-based aldol reactions, the oxazolidinone-installed bisimide 1a from 3-(trifluoromethyl)glutaric acid was employed for Mannich reactions with tosylated imines 2 as electrophiles to successfully obtain the corresponding adducts in a stereoselective manner.
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ژورنال
عنوان ژورنال: Chemical and Pharmaceutical Bulletin
سال: 1994
ISSN: 0009-2363,1347-5223
DOI: 10.1248/cpb.42.748