Biomacromolecules as Ligands for Artificial Metalloenzymes

First coordination sphere interactions usually are involved in metal-catalyzed enantioselective transformations: a chiral ligand directly linked to the metal dictates the enantiomeric outcome of a given reaction. A novel concept has emerged in the past 30 years: achiral metal complexes are inserted into proteins or DNA and the resulting artificial metalloenzymes catalyze various enantioselective transformations. In these hybrid catalysts, enantioselection is achieved with the help of the second coordination sphere, that is, a subtle combination of secondary interactions between the biomolecular scaffold, the catalyst, and the substrate. This chapter discusses the design of artificial metalloenzymes and their use in homogeneous catalysis.