Simply modified chiral diphosphine:: Catalyst recycling via non-covalent absorption on carbon nanotubes

A new type of recyclable chiral catalyst system was developed by absorption of pyrene-modified Pyrphos rhodium catalyst onto carbon nanotubes via pi-pi stacking interaction. This modified catalyst was successfully applied in the asymmetric hydrogenation of alpha-dehydroamino esters for nine cycles without obvious deterioration of activity and enantioselectivity.