“…In fact, ( S )‐(−)‐2,2′‐diamino‐6,6′‐dimethylbiphenyl has negative specific rotation in non‐acidic solvents ([α] D =−51.7°±2.4 in EtOH,1 [α] D =+34° in 10% HCl2). 3 Thus, the resolution of racemic 2,2′‐diamino‐6,6′‐dimethylbiphenyl in the Supporting Information should be corrected to read L ‐(+)‐tartaric acid (sometimes given as d ‐tartaric acid in the literature3) gives ( R )‐(+)‐2,2′‐diamino‐6,6′‐dimethylbiphenyl. Then ( S )‐(−)‐2,2′‐diamino‐6,6′‐dimethylbiphenyl enriched materials can be resolved with D ‐(−)‐tartaric acid.…”