Abstrakt
Homogeneous- and enzymatic catalysis offer complementary means to generate enantiomerically pure compounds. Incorporation of achiral biotinylated rhodiumdiphosphine complexes into (strep)avidin yields artificial metalloenzymes for the hydrogenation of N-protected dehydroaminoacids (Scheme). A chemogenetic optimization procedure allows to produce both enantiomers of acetamidoalanine in good enantioselectivity (up to 96% ee). Analysis of the performance of these hybrid catalysts reveal features reminsiscent both of enzymatic and of homogeneous systems.
![](https://webarchiv.lib.cas.cz:443/wayback/20210730205806im_/https://www.uochb.cz/upload/files/70/7e/707e46f94afb905032da5c14f6122c6a5bc76625.png)
Scheme. Artificial metalloenzymes for enantioselective hydrogenation reactions. The host protein (either avidin or streptavidin) displays a high affinity for the biotin anchor. Introduction of a spacer and variation of the ligand scaffold allows to chemically optimize the enantioselectivity. Fine tuning of the selectivity can be achieved via site-directed mutagenesis of the (strept)avidin.