Chiral thioureas with 1-arylethyl and 1-arylethyl-2-2-2-trifluoroethyl (Ar = Ph, 1-Napht, 9-Anthr) scaffolds were used as hosts to recognize acetate and chiral mandelates. The higher binding obtained with the trifluoromethyl analogue is also reflected in the higher selectivity factor for one enantiomer. The C2 symmetry was also indispensable to obtain selectivity.
