26153-26-4Relevant articles and documents
Enzymatic conversion of unnatural amino acids by yeast D-amino acid oxidase
Caligiuri, Antonio,D'Arrigo, Paola,Rosini, Elena,Tessaro, Davide,Molla, Gianluca,Servi, Stefano,Pollegioni, Loredano
, p. 2183 - 2190 (2007/10/03)
Unnatural amino acids, particularly synthetic α-amino acids, are becoming crucial tools for modern drug discovery research. In particular, this application requires enantiomerically pure isomers. In this work we report on the resolution of racemic mixtures of the amino acids D,L-naphthylalanine and D,L-naphthylglycine by using a natural enzyme, D-amino acid oxidase from the yeast Rhodotorula gracilis. A significant improvement of the bioconversion is obtained using a single-point mutant enzyme designed by a rational approach. With this D-amino acid oxidase variant the complete resolution of all the unnatural amino acids tested was obtained: in this case, the bioconversion requires a shorter time and a lower amount of biocatalyst compared to the wild-type enzyme. The simultaneous production of the corresponding α-keto acid, a possible precursor of the amino acid in the L-form, improves the significance of the procedure.
Carbonylation of Aryl Halides and Vinyl Bromides Mediated by Tetracarbonylcobalt Anion
Miura, Masahiro,Akase, Fumiaki,Shinohara, Masato,Nomura, Masakatsu
, p. 1021 - 1026 (2007/10/02)
The reaction of aryl halides (1a-g) with octacarbonyldicobalt in the presence of methyl iodide and sodium hydroxide under phase-transfer conditions was found to give a mixture of aryl methyl ketones (2a-g) and aromatic carboxylic acids (3a-h).From vinyl halides (9a-c), however, the corresponding carboxylic acids (10a-c) were obtained exclusively.
COBALT-CATALYZED LOW PRESSURE DOUBLE CARBONYLATION OF ARYL AND SECONDARY BENZYL HALIDES
Francalanci, F.,Bencini, E.,Gardano, A.,Vincenti, M.,Foa, M.
, p. C27 - C30 (2007/10/02)
α-Ketoacids can be easily synthesized with satisfactory yields and selectivities by carbonylation of aryl halides and secondary benzyl halides under very mild conditions.The reactions are catalyzed by Co2(CO)8 in alcoholic solvents; the presence of a methyl source (dimethyl sulfate or methyl iodide) is necessary for the carbonylation of the aryl halides.Base, temperature and solvent have large effects on the course of the reaction.