The highest enantioselectivity
of [delta]-iodo-[gamma]-lactonization (18%ee) was also recorded for menthol ester 2a.
Despite some room for improvement, especially (i) improvement of the enantioselectivity
of carboalumination and (ii) realization of higher turnover numbers through elevation of the current level of 20-[10.sup.3] to [greater than or equal to] [10.sup.3]-[10.sup.4] or higher, the ZACA reaction promises to provide a widely applicable, efficient, and selective asymmetric method for the synthesis of a variety of chiral organic compounds.
Considering that 1a containing pyrrolidinium cation gave the higher enantioselectivity
than pyrrolidinepyrrolidine combined diamine catalyst , we propose that the electrostatic interaction with pyrrolidinium cation of 1a and nitro oxygen of trans-[beta]-nitrostyrene can form the transition state I and the steric hindrance of pyrrolidinium cation of 1a can shield the access of the nitro group.
The effect of enantioselectivity
of 21 on the biological activity was also studied.
in the methylation of the catecholic phase I metabolites of methylenedioxy designer drugs and their capability to inhibit catechol-O-methyltransferase-catalyzed dopamine 3-methylation.
Among the topics are valence photoelectronic circular dichroism of gas phase enantiomers, the infrared and Raman detection of transient chirality recognition in the gas phase with ethanol as a case study, enantioselectivity
in gas-phase ion-molecule reactions, equilibrium methods, deoxy oligonucliotides as chiral references for discriminating enantiomeric amino acids under mass spectrometry, solution-phase versus gas-phase chiral recognition by electrospray ionization mass spectrometry with a case study of two chiral selector classes.
Methods to increase enantioselectivity
of lipases and esterases.
They also exhibit good chemoselectivity, regioselectivity and enantioselectivity
, and as hydrolases they do not require cofactors.
The results are in accordance to a reported result where enantioselectivity
of other lipases toward primary alcohol is much lower than to secondary alcohol .
reported on the enantioselectivity
of oPPy films and colloids towards amino acids (L- and D-glutamic acid) .
However, in spite of high enantioselectivity
, the yield of the applied microbial Baeyer-Villiger reaction was low.
Reetz, A practical high-throughput screening system for enantioselectivity
by using FTIR spectroscopy, Chemistry-A European J.