5445-19-2Relevant articles and documents
Diastereo- And Enantioselective Synthesis of Quaternary α-Amino Acid Precursors by Copper-Catalyzed Propargylation
Zhu, Qiongqiong,Meng, Beibei,Gu, Congzheng,Xu, Ye,Chen, Jie,Lei, Chuanhu,Wu, Xiaoyu
supporting information, p. 9985 - 9989 (2019/12/24)
A diastereo- and enantioselective propargylic substitution reaction between propargylic carbonates and α-substituted nitroacetates catalyzed by a Cu-pybox complex is described. This method allows the preparation of a series of non-proteinogenic quaternary α-amino acid precursors featuring two contiguous stereogenic centers and a terminal alkyne moiety in high yields with good to excellent diastereo- and enantioselectivities in most cases. The propargylated adducts were elaborated into a diverse set of quaternary α-amino acid derivatives.
GC separation of enantiomers of alkyl esters of 2-bromo substituted carboxylic acids enantiomers on 6-tbdms-2,3-di-alkyl- β- And γ-cyclodextrin stationary phases
Spanik, Ivan,Kaceriakova, Darina,Krupcik, Jan,Armstrong, Daniel Wayne
, p. 279 - 285 (2014/06/09)
The gas chromatographic separation of enantiomers of 2-Br carboxylic acid derivatives was studied on four different 6-TBDMS-2,3-di-O-alkyl- β- and -γ-CD stationary phases. The differences in thermodynamic data {ΔH and -ΔS} for the 15 structurally related
Enoate reductase-mediated preparation of methyl (S)-2-bromobutanoate, a useful key intermediate for the synthesis of chiral active pharmaceutical ingredients
Brenna, Elisabetta,Gatti, Francesco G.,Manfredi, Alessia,Monti, Daniela,Parmeggiani, Fabio
, p. 262 - 268 (2012/06/18)
Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of α-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.
