Abstract The direct immobilization of two different C-5-propargyl ether-modified, chiral N- salicylidene vanadyl (V) tert-leucinates onto 4-azidomethyl-substituted polystyrene by click chemistry was examined. Among the eight different solvents investigated, the resulting polystyrene-supported catalysts promote the asymmetric, aerobic oxidation of α-hydroxy (thio) esters and amides with enantioselectivities of up to 99% ee (selectivity factor up to ...