100992-58-3Relevant articles and documents
Enzymatic racemization of amines catalyzed by enantiocomplementary ω-Transaminases
Koszelewski, Dominik,Grischek, Barbara,Glueck, Silvia M.,Kroutil, Wolfgang,Faber, Kurt
, p. 378 - 383 (2011)
A strategy for the biocatalytic racemization of primary α-chiral amines was developed by employing a pair of stereocomplementary PLP-dependent ω-transaminases. The interconversion of amine enantiomers proceeded through reversible transamination by a prochiral ketone intermediate, either catalyzed by a pair of stereocomplementary ω-transaminases or by a single enzyme possessing low stereoselectivity. To tune the system, the type and concentration of a nonchiral amino acceptor proved to be crucial. Finally, racemization could be achieved by the cross-transamination of two different amines without a requirement for an external amino acceptor. Several synthetically and industrially important amines could be enzymatically racemized under mild reaction conditions. ω-Transaminases play ping-pong: A biocatalytic protocol for the 'clean' racemization of α-chiral prim-amines was developed by an equilibrium-controlled deamination/amination sequence catalyzed by a pair of (R)- and (S)-ω-transaminases (see scheme).
Organocatalytic Kinetic Resolution of Sulfoximines
Dong, Shunxi,Frings, Marcus,Cheng, Hanchao,Wen, Jian,Zhang, Duo,Raabe, Gerhard,Bolm, Carsten
supporting information, p. 2166 - 2169 (2016/03/05)
An efficient kinetic resolution of sulfoximines with enals was realized using chiral N-heterocyclic carbene (NHC) catalysts. The stereoselective amidation proceeds without additional acyl transfer agent. Both enantiomers of the sulfoximines can be obtaine
Stereoselective Aldol Reaction with Chiral Secondary Acetamides
Devant, Ralf,Braun, Manfred
, p. 2191 - 2207 (2007/10/02)
The deprotonated acetamides 4a - c and 5a - c are added to prochiral carbonyl compounds.The influence of the solvent, of the reaction temperature, and of the enolate gegenion on the ratio of the isomeric products 8/9, 18/19, and 26/27, respectively, are studied.The highest degree of diastereoselectivity are observed, when the titanium enolate of the acetamide 4a or the threefold deprotonated N-acetyl-α-phenylglycinol (5a) is used.The diastereomers 18a - d, formed in excess in the addition of 5a to aldehydes, are isolated in pure from by a single recrystallization, and afford the enantiomerically pure β-hydroxy carboxylic acids 3a - d.Thereby, the chiral auxiliary, α-phenylglycinol (14), is recovered.