Lewis acid-catalyzed highly diastereoselective asymmetric Friedel–Crafts alkylation of arenes with a chiral N-tert-butanesulfinylimino ester is described. The reaction can be accomplished with ease in the presence of a catalytic amount of In(OTf)3 at room temperature, providing a series of enantiomerically enriched α-arylglycines in good yields and with excellent diastereoselectivities (up to 99% de). Highly stereoselective double Friedel–Crafts alkylation to afford dialkylation product was also investigated.