Preparation of enantiomerically enriched aromatic β-amino acids via enzymatic resolution

Enantioselective acylation of alcohols with fluorinated β-phenyl-β-lactams in the presence of Burkholderia cepacia lipase

“…The studies seem to be restricted to the hydrolysis of N-phenylacetyl derivatives of b-fluoroalkyl-and b-fluoroaryl-b-amino acids by penicilline acylase [6][7][8] and to the hydrolysis of b-fluorophenyl-b-alanine ethyl ester by Burkholderia cepacia lipase (lipase PS). 9 b-Lactams (2-azetidinones) are interesting precursors of b-amino acids, while the lipases are highly usable and economical catalysts in organic chemistry. The enantioselective hydrolyses of many b-lactams with CAL-B (Novozym 435 preparation) were previously reported with 1 equiv of water in diisopropyl ether (DIPE) at an elevated temperature.…”

Production of enantiomerically pure (S)-β-phenylalanine and (R)-β-phenylalanine by penicillin G acylase from Escherichia coli in aqueous medium

“…Moreover, the PGA-catalyzed acylation of BPA (Reaction B, see Scheme 1) revealed high acylation rate with a reaction time was 45 min. Previous results indicated a reaction time of 48 h for the acylaion of BPA catalyzed by an aminoacylase (Groeger et al 2004) and 15 h for resolution of BPA ethyl ester catalyzed by a lipase (Faulconbridge et al 2000). Therefore, from the viewpoint of the efficiency and environment protecting, PGA-catalyzed acylation of BPA is a promising alternative.…”

“…For examples, (R)-BPA is a component of astins A-C, antitumor cyclopentapeptides, isolated from the roots of a medicinal plant Aster tataricus (Morita et al 1995); (S)-BPA can be used to synthesis of pyloricidin A-D, novel anti-Helicobacter pylori antibiotics (Nagano et al 2001). Methods for producing enantiomerically pure BPA include homologation of enantiomerically pure a-amino acids (Podlech 2005), asymmetric synthesis by application of chiral sulfoxides (Sivakumar et al 2001), and enantiomeric-specific hydrolysis of corresponding racemic substances using biocatalysts, such as lipase (Faulconbridge et al 2000), a-chymotrypsin (Cohen and Weinstein 1964), penicillin G acylase (Soloshonok et al 1995) and aminoacylase (Groeger et al 2004). However, from the viewpoint of industrial application and environmental protection, the production of enantiomerically pure BPA is still a challenging project.…”

Enzymatic Aminolysis and Ammonolysis Processes in the Preparation of Chiral Nitrogenated Compounds

“…These compounds can be easily prepared in its racemic form, and it is possible to carry out a biocatalytic resolution by acylation of the amino group, or by hydrolysis, transesterification or aminolysis through the ester function. The bioresolution of aromatic β-aminoesters via enzymatic hydrolysis has been carried out [67] and this methodology has been most exhaustively used than acylation of amino group or aminolysis of the ester, for instance, racemic β-aminobutyrate esters bearing the amino function protected have been resolved by enantioespecific transesterification with butanol and CALB as biocatalyst [68]. It seems that the resolution by acylation of amino group Scheme 25.…”