105099-19-2Relevant articles and documents
A chiral pool strategy for the synthesis of enantiopure hydroxymethyl-substituted pyridine derivatives
Eidamshaus, Christian,Reissig, Hans-Ulrich
experimental part, p. 6056 - 6069 (2011/12/15)
A simple procedure for the synthesis of enantiopure hydroxymethyl- substituted pyridine derivatives is presented. The developed method is based on TMSOTf-promoted cyclocondensations of β-ketoenamides, leading to differently substituted 4-hydroxypyridine/4-pyridone derivatives. The required β-ketoenamides were prepared by acylation ofeasily available enamino ketones with suitably protected enantiopure carboxylic chlorides. Most of the experiments were performed with D-mandelic acid as starting material. It has been shown that all steps occur essentially without racemisation. Several of the prepared 4-pyridone derivatives were transformed into the corresponding pyrid-4-yl nonaflates and subjected to a series of palladium-catalysed transformations, such as Suzuki, Heck or Sonogashira reactions. In addition, regioselective side-chain functionalisation of unsymmetrically 2,6-disubstituted pyridine derivatives was accomplished by application of Boekelheide rearrangements of the corresponding pyridine N-oxides. The presented methods allow a flexible, rapid and scalable approach to highly substituted, enantiopure pyridine derivatives. A new route to hydroxymethyl-substituted pyridine derivatives, starting from enantiopure α-hydroxy carboxylic acids, is described. The synthetic value of the method is demonstrated by multifaceted functionalisation reactions of the prepared pyridine derivatives, leading to a series of highly substituted enantiopure pyridine derivatives.
Nα-Fmoc-protected ω-azido- and ω-alkynyl-L- amino acids as building blocks for the synthesis of "clickable" peptides
Isaad, Alexandra Le Chevalier,Barbetti, Francesca,Rovero, Paolo,D'Ursi, Anna Maria,Chelli, Mario,Chorev, Michael,Papini, Anna Maria
experimental part, p. 5308 - 5314 (2009/06/18)
The growing interest in the 1,4-disubstituted-1,2,3-triazolyl moiety as an amide bond surrogate and its formation through very mild, chemoselective, and bioorthogonal CuI-catalyzed Huisgen 1,3-dipolar [3+2] cycloaddition of an alkynyl to an azi
A NOVEL APPLICATION OF THE CHIRAL REAGENT (S)-2-N-(N'-BENZYLPROLYL)-AMINOBENZALDEHYDE: SYNTHESIS OF OPTICALLY PURE α-METHYLVALINE AND α-METHYLGLUTAMIC ACID
Belokon, Yu. N.,Motsishkite, S. M.,Tararov, V. I.,Maleev, V. I.
, p. 1355 - 1360 (2007/10/02)
The synthesis of α-methyl substituted amino acids using Ni(II) complexes of the Schiff base obtained from alanine and (S)-2-N-(N'-benzylpropyl)aminobenzaldehyde is described.This complex was alkylated with isopropyl bromide, gramine iodomethylate, and methyl acrylate (in a Michael reaction).From the resulting mixtures of products, diastereomerically pure complexes were obtained by crystallization or silica gel chromatography.Both (S)- and (R)-enantiomers of the optically active amino acids α-Me-Val and α-MeGlu were obtained after decomposing the diastereomerically pure complexes.
