Artificial Metalloenzymes: (Strept)avidin as Host for Enantioselective Hydrogenation by Achiral Biotinylated Rhodium−Diphosphine Complexes
Journal of the American Chemical Society
Pages / Article-Number
Formation constant (achiral biotinylated amidodiphosphine ligands prepn. and complexation with rhodium in (strept)avidin hosts as artificial metalloenzymes for enantioselective hydrogenation of acetamidoacrylate); Avidins Role: BSU (Biological study, unclassified), CAT (Catalyst use), BIOL (Biological study), USES (Uses) (complexes; achiral biotinylated amidodiphosphine ligands prepn. and complexation with rhodium in (strept)avidin hosts as artificial metalloenzymes for enantioselective hydrogen
We report on the generation of artificial metalloenzymes based on the noncovalent incorporation of biotinylated rhodium−diphosphine complexes in (strept)avidin as host proteins. A chemogenetic optimization procedure allows one to optimize the enantioselectivity for the reduction of acetamidoacrylic acid (up to 96% ee (R) in streptavidin S112G and up to 80% ee (S) in WT avidin). The association constant between a prototypical cationic biotinylated rhodium−diphosphine catalyst precursor and the host proteins was determined at neutral pH: log Ka = 7.7 for avidin (pI = 10.4) and log Ka = 7.1 for streptavidin (pI = 6.4). It is shown that the optimal operating conditions for the enantioselective reduction are 5 bar at 30 °C with a 1% catalyst loading.