960352-49-2Relevant academic research and scientific papers
Nitrile biotransformations for the synthesis of highly enantioenriched β-hydroxy and β-amino acid and amide derivatives: A general and simple but powerful and efficient benzyl protection strategy to increase enantioselectivity of the amidase
Ma, Da-You,Wang, De-Xian,Pan, Jie,Huang, Zhi-Tang,Wang, Mei-Xiang
, p. 4087 - 4091 (2008/09/20)
(Chemical Equation Presented) Biotransformations of a number of racemic β-hydroxy and β-amino nitrile derivatives were studied using Rhodococcus erythropolis AJ270, the nitrile hydratase and amidase-containing microbial whole cell catalyst, under very mild conditions. The overall enantioselectivity of nitrile biotransformations was governed predominantly by the amidase whose enantioselectivity was switched on remarkably by an O- and a N-benzyl protection group of the substrates. While biotransformations of β-hydroxy and β-amino alkanenitriles gave low yields of amide and acid products of very low enantiomeric purity, introduction of a simple benzyl protection group on the β-hydroxy and β-amino of nitrile substrates led to the formation of highly enantioenriched β-benzyloxy and β-benzylamino amides and acids in almost quantitative yield. The easy protection and deprotection operations, high chemical yield, and excellent enantioselectivity render the nitrile biotransformation a useful protocol in the synthesis of enantiopure β-hydroxy and β-amino acids.
Efficient resolution of racemic N-benzyl β3-amino acids by iterative liquid-liquid extraction with a chiral (salen)cobalt(iii) complex as enantioselective selector
Dzygiel, Pawel,Monti, Chiara,Piarulli, Umberto,Gennari, Cesare
, p. 3464 - 3471 (2008/09/20)
The efficient (up to 93% ee) resolution of racemic N-benzyl β3-amino acids has been achieved by an iterative (two cycle) liquid-liquid extraction process using a lipophilic chiral (salen)cobalt(iii) complex [CoIII(1)(OAc)]. As a result of the resolution by extraction, one enantiomer of the N-benzyl β3-amino acid predominated in the aqueous phase, while the other enantiomer was driven into the organic phase by complexation to cobalt. The complexed amino acid was then quantitatively released into an aqueous phase, by a reductive (CoIII → Co II) counter-extraction using l-ascorbic acid. The reductive cleavage allowed for the recovery of the cobalt(ii) selector in up to 90% yield (easily re-oxidable to CoIII with air/AcOH). The Royal Society of Chemistry.
