The widely applicable TRIP phosphoric acid catalyst has been immobilized on polystyrene using a copolymerization-based strategy. The resin (PS-TRIP) has proven to be highly active and enantioselective in the asymmetric allylboration of aldehydes. Moreover, it has shown to be extremely robust, as it can be reused for 18 times, after which it still retained its activity. Lastly, to further prove the benefits of the immobilization, a continuous flow experiment spanning 28 h has been carried out with very high yields and ee's.

A polystyrene-supported, recyclable, BINOL-derived chiral phosphoric acid has been applied to the desymmetrization of meso-diones to produce enantioenriched cyclohexenones.