A substrate-driven approach to determine reactivities of α,β-unsaturated carboxylic esters towards asymmetric bioreduction.
The degree of C=C bond activation in the asymmetric bioreduction of α,β-unsaturated carboxylic esters by ene-reductases was studied, and general recommendations to render these "borderline-substrates" more reactive towards enzymatic reduction are proposed. The concept of "supported substrate activation" was developed. In general, an additional α-halogenated substituent proved to be beneficial for enzymatic activity, whereas β-alkyl or β-aryl substituents were detrimental for the reactivity of nonhalogenated substrates, and α-cyano groups showed little effect. The alcohol moiety of the ester functionality was found to have a strong influence on the reaction rate. Overall, activities were determined by both steric and electronic effects.
ACIB GmbH c/o, Biocatalytic Synthesis, University of Graz, Heinrichstrasse 28, 8010-Graz, Austria.
Gábor
G
Tasnádi
Christoph K
CK
Winkler
Dorina
D
Clay
Nargis
N
Sultana
Walter M F
WM
Fabian
Mélanie
M
Hall
Klaus
K
Ditrich
Kurt
K
Faber
D055162:Biocatalysis; D002264:Carboxylic Acids / Q000737:chemistry*; D004952:Esters; D015394:Molecular Structure; D010088:Oxidoreductases / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity
D002264:Carboxylic Acids; D004952:Esters; D010088:Oxidoreductases