136814-99-8Relevant articles and documents
Chemoenzymatic approaches to the dynamic kinetic asymmetric synthesis of aromatic amino acids
Chaplin, Jennifer A.,Levin, Michael D.,Morgan, Brian,Farid, Nancy,Li, Jen,Zhu, Zuolin,McQuaid, Jeff,Nicholson, Lawrence W.,Rand, Cynthia A.,Burk, Mark J.
, p. 2793 - 2796 (2007/10/03)
Enzymatic approaches for the production of amino acids by nitrilases are described. Dynamic kinetic asymmetric synthesis conditions were established for the aromatic aminonitriles, phenylglycinonitrile and 4- fluorophenylglycinonitrile, at high pH to produce the corresponding amino acid products in high enantiomeric excess. N-Acylation of aromatic aminonitriles led to spontaneous racemization at pH 8, allowing preferential enzymatic hydrolysis of the (R)-enantiomer to afford the product N-acylamino acids in up to 99% enantiomeric excess (ee).
Efficient chemoenzymatic synthesis of enantiomerically pure α-amino acids
Beller, Matthias,Eckert, Markus,Geissler, Holger,Napierski, Bernd,Rebenstock, Heinz-Peter,Holla, E. Wolfgang
, p. 935 - 941 (2007/10/03)
A general two-step chemoenzymatic synthesis for enantiomerically pure natural and nonnatural α-amino acids is presented. In the first step of the sequence, the ubiquitous educts aldehyde, amide and carbon monoxide react by palladium-catalyzed amidocarbonylation to afford the racemic N-acyl amino acids in excellent yields. In the second step, enzymatic enantioselective hydrolysis yields the free optically pure a-amino acid and the other enantiomer as the N-acyl derivative, both in optical purities of 85-99.5% ee. The advantage of the chemoenzymatic process compared to other amino acid synthesis are demonstrated by the preparation of various functionalized (-OR, -Cl, -F, -SR) α-amino acids on a 10-g scale.
HOMOCHIRAL HETEROORGANIC ANALOGS OF NATURAL COMPOUNDS. I. PREPARATIVE BIOCATALYTIC METHOD OF OBTAINING FLUORINE-CONTAINING L- AND D-PHENYLGLYCINES
Soloshonok, V. A.,Galaev, I. Yu.,Shvyadas, V. K.,Kozlova, E. V.,Kotik, N. V.,et al.
, p. 228 - 232 (2007/10/02)
A biocatalytic method of obtaining homochiral o- and p-fluorine-substituted phenylglycines by enantiomeric hydrolysis from N-phenylacetyl or N-acetyl derivatives under the action of Escherichia coli penicillin acylase or Streptoverticillium olivoreticuli aminoacylase is proposed.The L form of the amino acid and the unhydrolyzed D-enantiomer of the initial derivative are separated by extraction and chromatographic methods.The acid hydrolysis of the D-enantiomers of N-phenylacetyl derivatives of fluorine-substituted phenylglycines leads to partial (about 15percent) racemization.With a substantially higher (by two orders of magnitude) concentration of enzyme and an increase in the reaction time it is possible to use penicillinase as a catalyst for the hydrolysis of the D-enantiomer of the N-phenylacetyl derivative not accompanied by any appreciable racemization whatever.