Quantitative analyses of biochemical kinetic resolution of enantiomers. 2. Enzyme-catalyzed esterifications in water-organic solvent biphasic systems

Kinetic Resolution of Optically Pure 3-Alkanol by Pseudomonas cepacia Lipase-Catalyzed Transesterification with Vinyl Acetate in Organic Solvent

“…It has been reported that the reaction is reversible based on the fact that the enantioselectivity [E: the enantiomeric ratio for the homocompetitive reaction, i.e., as the reaction is irreversible] at low conversion is greater than that at high conversion ( 50%) in Pseudomonas fluorescens lipase (PFL)-catalyzed transesterification with racemic b-methyl-(2-thiophene)propanol in chloroform (9). Furtheremore it has been reported that the optical resolution data did not fit the previously resolution format (5,(10)(11)(12)based on the observation: the E value increases with c in the range of below 0.5 in Pseudomonas cepacia lipase (PCL)-catalyzed transesterification with racemic sulcatol, ( )-6-methyl-5-hepten-2-ol, in chlorinated solvents (13). In the previous papers on PCL-catalyzed transesterification with 2-alkanol, we reported that the E value showed the maxima at around 0.5 of c in all systems studied (14) and that the reaction of enantiomerically enriched substrate was a powerful strategy for kinetic resolution of chiral compounds with high optical purity (15).…”

Kinetic Resolution of Enantiomers in Enantiomerically Enriched 2-Alkanol by Pseudomonas cepacia Lipase Catalyzed Transesterification with Vinyl Acetate in Organic Solvent.

“…The results in this paper demonstrate that the proposed equations are applicable to enzymatic and catalytic reactions and that they are independent of reversibility /irreversibility of the reactions and of obedience to the optical resolution theory [Eqs. (1) and (2)]. The present procedure will be a powerful strategy for the preparation of optically pure enantiomers from enatiomerically enriched substrates, especially the resolutions of fast-reacting enantiomer by the enzymatic reactions with a moderate enantioselectivity and slow-reacting enatiomer by the reversible enzymatic reactions.…”

“…3B, curve a). (1) was resolved by repeating the transesterification three times and twice for optically pure (S)- (1). This procedure will useful for kinetic resolution of highly enantiomerically enriched fast reacting enatiomer in the racemate by enzymatic reactions with a moderate enantioselectivity and for the resolution of optically pure slow reacting enantiomer by the reversible enzymatic reactions.…”

Kinetic Analysis and Simulation Studies for Lipase-Catalysed Resolution of Racemic 2-Methyl-1-Pentanol

“…Later, the basic concept was extended to reversible systems in order to describe enantioselective esterification reactions in biphasic water-organic media (Chen et al, 1987). However, this kind of approach is mainly limited to low substrate concentrations where the reaction follows first-order kinetics and is generally not applicable to multi-substrate reaction sequences.…”