- A rapid and efficient one-pot method for the reduction of N-protected α-amino acids to chiral α-amino aldehydes using CDI/DIBAL-H
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N-Protected amino acids can be easily converted into chiral α-amino aldehydes in a one-pot reaction by activation with CDI followed by reduction with DIBAL-H. This method delivers Boc-, Cbz- and Fmoc-protected amino aldehydes from proteinogenic amino acids in very good isolated yields and complete stereointegrity.
- Ivkovic, Jakov,Lembacher-Fadum, Christian,Breinbauer, Rolf
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p. 10456 - 10460
(2015/11/10)
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- Resolution and absolute configuration of some a-aminoacetals: En route to enantiopure N-protected a-aminoaldehydes
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The first successful resolution of rac-a-aminoacetals via diastereoisomeric salt formation with optically pure N-protected aminoacids is reported. The absolute configuration assignment of a-aminoacetal enantiomers is performed by an entirely non-racemizing chemical correlation method involving N-protection and a new efficient hydrolysis step followed by a reduction of the resulting N-protected a-aminoaldehyde intermediates. A racemization method of optically enriched a-aminoacetals is exemplified to allow valorisation of both enantiomers. Springer-Verlag 2011.
- Albalat-Serradeil, Muriel,Primazot, Geraldine,Wilhelm, Didier,Vallejos, Jean-Claude,Vanthuyne, Nicolas,Roussel, Christian
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p. 687 - 696
(2012/09/22)
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- IMPROVED AMINOHYDROXYLATION OF ALKENES
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The invention relates to a process for the aminohydroxylation of alkenes using N-oxycarbamate reagents, e.g. N-acyloxycarbamate, N-alkyloxycarbonyloxycarbamate and N-aralkoxycarbonyloxycarbamate reagents. The invention particularly relates to an intermolecular aminohydroxylation reaction that can be carried out in the absence of added base. The invention also relates to novel N-oxycarbamate reagents that are stable crystalline materials. The process of the invention is useful in the synthesis of compounds having a vicinal amino alcohol moiety, such as biologically active compounds.
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Page/Page column 51
(2012/01/06)
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- Alkyl 4-chlorobenzoyloxycarbamates as highly effective nitrogen source reagents for the base-free, intermolecular aminohydroxylation reaction
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Ethyl-(7), benzyl-(8), tert-butyl-(9), and fluorenylmethyl-4- chlorobenzoyloxycarbamates (10) have been prepared as storable and easy-to-prepare nitrogen sources for use in the intermolecular Sharpless aminohydroxylation reaction and its asymmetric variant. These reagents were found to be effective under base-free reaction conditions. The scope and limitations of these methods have been explored using a variety of alkenes, among which, trans-cinnamates, in particular, proved to be good substrates.
- Harris, Lawrence,Mee, Simon P. H.,Furneaux, Richard H.,Gainsford, Graeme J.,Luxenburger, Andreas
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p. 358 - 372
(2011/04/17)
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- Facile Reduction of Intermediates from Carboxylic Acids and 6-Nitro-1-(2-nitrophenylsulfonyloxy)benzotriazole with Sodium Borohydride to Alcohols
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Reduction of activated intermediates derived from 6-nitro-1-(2-nitrophenylsulfonyloxy)-benzotriazole and carboxylic acids with sodium borohydride readily afforded the corresponding alcohols in 71-93percent yields.Keywords: 6-nitro-1-(2-nitrophenylsulfonyloxy)benzotriazole; 1-acyloxy-6-nitrobenzotriazole; 3-acyl-6-nitrobenzotriazole 1-oxide; sodium borohydride reduction; alcohol synthesis
- Okawara, Tadashi,Ikeda, Norihiro,Yamasaki, Tetsuo,Furukawa, Mitsuru
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p. 3628 - 3631
(2007/10/02)
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