Proteins, the functional molecules in biological systems, are sophisticated chemical devices that have evolved over billions of years. Their function is intimately related to their three-dimensional structure and elegantly regulated by conformational changes through allosteric regulators and a number of reversible or unidirectional post-translational modifications. This functional diversification in response to external stimuli allows for an orderly and timely progression of intra- and extracellular events. In contrast, enantioselective catalysts generally exhibit limited conformational flexibility and thereby exert a single specific function. Exploiting the features of conformationally flexible asymmetric ligands and the variable coordination patterns of rare earth metals, we demonstrate dynamic structural and functional changes of a catalyst in asymmetric catalysis, leading to two distinct reaction outcomes in a single flask.