153545-91-6

Upstream product

• 308087-12-9 Butyl 2-(4-ethylphenoxy)propionate 
• 197158-47-7 (R)-Butyl 2-(4-ethylphenoxy)propionate 
• 75121-14-1 p-Ethyl potassium phenolate 
• 99761-31-6 (+/-)-2-(4-ethylphenoxy)propanoic acid 
• 71-36-3 butan-1-ol 
• 154004-93-0 ethyl (R)-2-(4-ethylphenoxy)propionate 

Downstream Products

• 197158-47-7 (R)-Butyl 2-(4-ethylphenoxy)propionate 

Relevant academic research and scientific papers

A great improvement of the enantioselectivity of lipase-catalyzed hydrolysis and esterification using co-solvents as an additive

Addition of co-solvents such as tetrahydrofuran resulted in a great improvement of the enantioselectivity of lipase-catalyzed hydrolysis of butyl 2-(4-substituted phenoxy)propanoates in an aqueous buffer solution. On the other hand, lipase lyophilized from an aqueous solution containing the co-solvents catalyzed highly enantioselective esterification of 2-(4-substituted phenoxy)propionic acids, 2-(4-isobutylphenyl)propionic acid (ibuprofen), and 2-(6-methoxy-2-naph-thyl)propionic acid (naproxen) in an organic solvent. An increase in the E value up to two orders of magnitude was observed for some substrates. The origin of the enantioselectivity enhancement caused by the co-solvent addition was mainly attributed to a significant deceleration in the initial reaction rate for the incorrectly binding enantiomer, as compared with that for the correctly binding enantiomer. From the results of FT-1R, CD, and ESR spectra, the co-solvent addition was also found to bring about a partial destruction of the tertiary structure of lipase.

Metal ions dramatically enhance the enantioselectivity for lipase-catalysed reactions in organic solvents

We propose a simple and a powerful method to enhance the enantioselectivity for lipase-catalysed transformations in organic solvents by an addition of metal ion-containing water to the reaction mixture. In this paper, various metal ions such as LiCl or MgCl2 are tested to improve the enantioselectivity for the model reactions. The enantioselectivities obtained are dramatically enhanced, the E values of which are about 100-fold as compared with the ordinary conditions without a metal ion, for example, E = 200 by addition of LiCl. Furthermore, lowering the reaction temperature led to an almost perfect enantioselectivity of lipase in the presence of a metal ion, for example, E = 1300 by addition of LiCl. Also, a mechanism for the drastic enhancement by metal ions is discussed briefly on the basis of the EPR spectroscopic study and the initial rate for each enantiomer of the substrate. The Royal Society of Chemistry 2006.

A method to greatly improve the enantioselectivity of lipase-catalyzed hydrolysis using sodium dodecyl sulfate (SDS) as an additive

The addition of sodium dodecyl sulfate (SDS) resulted in a dramatic improvement of the enantioselectivity of the lipase-catalyzed hydrolysis of racemic butyl 2-(4-substituted phenoxy)propanoates, racemic butyl 2-(4-isobutylphenyl)propanoate, and racemic butyl 2-(6-methoxy-2-naphthyl) propanoate in an aqueous buffer solution. An increase in the E value by up to two orders of magnitude was observed for some esters. As to the effects of SDS on the structure of a lipase, FT-IR and fluorescence measurements suggest some conformational change and/or an increase of the flexibility of the lipase, although the native secondary structure of the lipase is held even in the presence of 100 mM SDS. The origin of the enantioselectivity enhancement brought about by the addition of SDS is briefly discussed on the basis of the values of the initial rates obtained for each enantiomer of the substrate.

Flexibility of lipase brought about by solvent effects controls its enantioselectivity in organic media

The behavior of the enantioselectivity of Candida rugosa lipase was studied in the esterification of 2-(4-substituted phenoxy)propionic acids with 1-butanol in aliphatic, aromatic, and ethereal solvents, (cyclohexane, heptane, toluene, benzene, isooctane, dibutylether, etc.). Changing the solvent from cyclohexane to tert-butyl methyl ether, the isotropic signal increased quickly and the spectral line narrowed in width. The enzyme enantioselectivity in organic solvents was mainly controlled by its flexibility. The enantioselectivity of lipase in organic solvents was closely correlated with the lipase flexibility brought about by the cooperative solvent effects rather than with a sole solvent property, e.g., dielectric constant and hydrophobicity.

Dimethyl sulfoxide as a co-solvent dramatically enhances the enantioselectivity in lipase-catalysed resolutions of 2-phenoxypropionic acyl derivatives

We recently reported that the enantioselectivity for subtilisin-catalysed hydrolysis of ethyl 2-(4-substituted phenoxy)-propionates in aqueous buffer is found to be dramatically enhanced by addition of dimethyl sulfoxide (DMSO). In our present work, as one of the useful methods for improving the enzyme's enantioselectivity, this approach using DMSO is tested for both hydrolysis and transesterification catalysed by various lipases. For instance, for Candida rugosa lipase-catalysed hydrolysis in aqueous buffer containing DMSO, the optimum additive conditions (50-65 vol% DMSO) markedly enhance the enantioselectivity toward the substrates used, as compared with that for no-additive conditions, in spite of a decrease in the enzymatic activity. On the other hand, for Pseudomonas cepacia lipase-catalysed hydrolysis, the addition of DMSO to the reaction medium enhances the enantioselectivity with an increase in the enzymatic activity. Also, the DMSO effect on the enantioselectivity can apply to the lipase-catalysed transesterification in organic solvent. A mechanism for the DMSO-induced enhancement of the lipase's enantioselectivity is briefly discussed on the basis of the values of the initial rates obtained for each enantiomer of the substrate used.

Optical resolution of aryloxypropionic acids and their esters by HPLC on cellulose tris-3,5-dimethyl-triphenylcarbamate derivative

Chiral chromatographic resolution of a series of antiphlogistic 2- aryloxypropionic acids and their methyl and ethyl esters was performed using a Chiralcel OD column. The CSP selected resolved most of the acids and esters efficiently, the enantiomers being well separated without requiring time consuming analysis. Chromatographic separation of R enriched samples was performed to determine the correct elution order. Using eluting systems such as hexane and 2-propanol, or hexane, 2-propanol and formic acid, the S enantiomer of all acids and esters was always found to elute first. We also considered the role of electron-donating or electron-withdrawing substituents (at the aryloxylic moiety) on the chiral resolution. It was shown that the electronic features of the substituents have more influence on the chiral interactions between the solutes and the CSP than their steric hindrance. Finally we determined, by molecular models, the interaction between CSP and solutes. In this way were able to determine all the potential sites for interactions, which are compatible with the conformations of the compounds and the structure of the stationary phase, and point out those interactions which enable chiral resolution.