Both enantiomers of 5 can be obtained in the Friedel-Crafts alkylation using SCP-ArMs with Bpy attached to residue 111, but by using different attachment strategies (Table , entries 6 and 9). The crystal structures of SCP_Q111BpyAla and SCP_Q111CBpy provide a structural indication for the observed differences in the enantioselectivities of these ArMs [almost 2x higher e.e., from 64:36 (R) for SCP_Q111CBpy to 20:80 (S) for SCP_Q111BpyAla]. The longer linker to the protein backbone in SCP_Q111CBpy, which has an additional -CH2-S-compared to SCP_Q111BpyAla, allows it to extend out from -helix 5 and adopt a more exposed position on the surface of the protein, compared to the BpyAla which is closer to the scaffold protein.