Metals in Biotechnology: Cr‐Driven Stereoselective Reduction of Conjugated C=C Double Bonds

Elemental metals are shown to be suitable sacrificial electron donors to drive the stereoselective reduction of conjugated C=C double bonds using Old Yellow Enzymes as catalysts. Both direct electron transfer from the metal to the enzyme as well as mediated electron transfer is feasible, although the latter excels by higher reaction rates. The general applicability of this new chemoenzymatic reduction method is demonstrated, and current limitations are outlined. OYE, OYE! Heavy metal and biocatalysis: Elemental metals are shown to be suitable sacrificial electron donors to drive the stereoselective reduction of conjugated C=C double bonds using Old Yellow Enzymes (OYEs) as catalysts. In this contribution we demonstrate that chemo‐ and enantioselective reductions catalyzed by OYEs can be driven by elemental metals as stoichiometric reductants.