Strain-dependent Enantioselectivity in Mechanochemically Coupled Catalytic Hydrogenation

The specific three-dimensional structure, e.g. the chirality, of the product of many important reactions is determined in large part by the structure of a catalyst, for example the ligand around a metal center, that makes the reaction tractable. Here, we demonstrate that the chiral selectivity of the hydrogenation of a methyl 2-amidoacrylate via a fixed bisphosphine Rh catalyst can be improved by embedding that catalyst into an appropriate heterogenous elastomeric support and transducing the mechanical deformation of the elastomer to the catalyst. The ratio of R and S product isomers is strain-dependent and reversible upon relaxing the support. Stretching the support by 50% in a single dimension increases the R:S ratio of the product by up to 32%.