114285-13-1Relevant articles and documents
Selective hydroalkoxycarbonylation of enamides to N-acyl amino acid esters: Synthetic applications and theoretical studies
Klaus,Neumann,Jiao,Von Wangelin, A. Jacobi,G?rdes,Strübing,Hübner,Hateley,Weckbecker,Huthmacher,Riermeier,Beller
, p. 3685 - 3700 (2004)
N-acyl amino acid esters are easily accessible from enamides by cobalt-catalyzed hydroalkoxycarbonylation in moderate to excellent yield. An important reaction parameter for selective carbonylation is the use of low hydrogen partial pressure, which prevents hydrogenation as a side reaction. The reported method is applicable to various enamides and alcohols. A DFT calculation of the catalytic cycle explains the preferred pathway of this reaction.
"Cofactor"-controlled enantioselective catalysis
Dydio, Pawel,Rubay, Christophe,Gadzikwa, Tendai,Lutz, Martin,Reek, Joost N. H.
supporting information; experimental part, p. 17176 - 17179 (2011/12/13)
We report an achiral bisphosphine rhodium complex equipped with a binding site for the recognition of chiral anion guests. Upon binding small chiral guests-cofactors-the rhodium complex becomes chiral and can thus be used for asymmetric catalysis. Screening of a library of cofactors revealed that the best cofactors lead to hydrogenation catalysts that form the products with high enantioselectivity (ee?s up to 99%). Interestingly, a competition experiment shows that even in a mixture of 12 cofactors high ee is obtained, indicating that the complex based on the best cofactor dominates the catalysis.
A general and accurate nmr determination of the enantiomeric purity of α-aminoacids and α-aminoacid derivatives
Calmes, Monique,Daunis, Jacques,Jacquier, Robert,Verducci, Jean
, p. 2285 - 2292 (2007/10/02)
Derivatization of α-aminoacids, α-aminoesters and α-aminolactones as N-acetyl derivatives allow the accurate NMR determination of the enantiomeric purity. In these conditions the major coordination site with a chiral shift reagent will correspond to the NMR observation site. Experimental factors leading to the highest ΔΔδ values are ascertained. No straightforward correlation with absolute configurations can be established.