Highly efficient dynamic kinetic resolution of secondary aromatic alcohols with low-cost and easily available acid resins as racemization catalysts
作者:Yongmei Cheng、Gang Xu、Jianping Wu、Chensheng Zhang、Lirong Yang
DOI:10.1016/j.tetlet.2010.02.152
日期:2010.4
A new and efficient dynamic kineticresolution (DKR) process of secondary aromatic alcohols was developed with acid resins as racemization catalysts. Acid resin CD8604 was shown to have excellent racemization activity and good biocompatibility. When employing CD8604 and complex acyl donors as racemization catalyst and acyl donor, respectively, enantiomerically pure aromatic acetate was obtained with
A recombinant Bacillus subtilis esterase (BsE) expressed in E. coli was found to exhibit excellent enantioselectivity (E was always greater than 100) towards m-substituted 1-phenylethanol acetates in the enantioselective hydrolysis reaction. An explanation for the high enantioselectivity observed towards these substrates was provided by molecular modeling. Moreover, the BsE also showed strong tolerance towards a high concentration of m-substituted 1-phenylethanol acetates (up to 1 M). Based on these excellent catalytic properties of BsE, a kind of m-substituted 1-phenylethanols, (R)-1-(3-chlorophenyl)ethanol, was efficiently synthesized in space-time yield of 920 g per L per day and 97% ee, indicating that the BsE was considered as a potentially ideal and promising biocatalyst for large-scale production of optically active m-substituted 1-phenylethanols.
Immobilized Manihot esculenta preparation as a novel biocatalyst in the enantioselective acetylation of racemic alcohols
作者:Luciana L. Machado、Telma L.G. Lemos、Marcos Carlos de Mattos、Maria da Conceicão F. de Oliveira、Gonzalo de Gonzalo、Vicente Gotor-Fernández、Vicente Gotor
DOI:10.1016/j.tetasy.2008.05.018
日期:2008.6
The enzymatic preparation obtained from a discard of Manihot esculenta roots has been successfully immobilized on calcium alginate hydrogels. This preparation has been tested as a chiral biocatalyst in the enzymatic acylation of a set of racemic aromatic alcohols. Depending on the reaction conditions, excellent enantioselectivities can be achieved. Some parameters that can alter the biocatalytic properties of the enzyme, such as solvent, temperature, acyl donor and substrate structure have been studied exhaustively in order to establish a deeper knowledge of this novel biocatalyst. (C) 2008 Elsevier Ltd. All rights reserved.