Squaramide-Catalyzed Enantioselective Michael Addition of Diphenyl Phosphite to Nitroalkenes
نویسندگان
چکیده
منابع مشابه
Thiourea catalyzed organocatalytic enantioselective Michael addition of diphenyl phosphite to nitroalkenes.
Bifunctional thiourea catalyzes the enantioselective Michael addition reaction of diphenyl phosphite to nitroalkenes. This methodology provides a facile access to enantiomerically enriched β-nitrophosphonates, precursors for the preparation of synthetically and biologically useful β-aminophosphonic acids. DFT level of computational calculations invoke the attack of the diphenyl phosphite to the...
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An efficient highly diastereo- and enantioselective direct Michael addition of nitroalkanes to nitroalkenes catalyzed by chiral squaramide catalyst has been developed. This organocatalytic reaction with a low catalyst loading (2 mol%) proceeded well to afford synthetically useful 1,3-dinitro compounds in high yields with high diastereoselectivities (up to 95 : 5 dr) and excellent enantioselecti...
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An efficient chiral squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to nitroalkenes has been developed. This reaction afforded the chiral pyrazol-3-ol derivatives in high to excellent yields (up to >99%) with high enantioselectivities (up to 94% ee) for most substrates under very low catalyst loading (0.25 mol%). This catalytic asymmetric reaction provides valuable an...
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Masked acyl cyanide (MAC) reagents are shown to be effective umpolung synthons for enantioselective Michael addition to substituted enones. The reactions are catalyzed by chiral squaramides and afford adducts in high yields (90-99%) and with excellent enantioselectivities (85-98%). The addition products are unmasked to produce dicyanohydrins that, upon treatment with a variety of nucleophiles, ...
متن کاملEnantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts
The highly enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes, promoted by binaphthyl-modified chiral bifunctional organocatalysts is described. This reaction afforded the chiral functionalized naphthoquinones in high yields (81-95%) and excellent enantioselectivities (91-98% ee) under low catalyst loading (1 mol %).
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ژورنال
عنوان ژورنال: Angewandte Chemie
سال: 2009
ISSN: 0044-8249
DOI: 10.1002/ange.200904779