“…[34] In particular, (R)-and (S)-indoline-2-carboxylic acids have been prepared by chemical resolution with diverse crystallizing agents, [19a,19c,20a,35] chemical synthesis through catalytic asymmetric hydrogenation of indoles, [36] intramolecular aryl aminations, [37] asymmetric deprotonation of N-Boc-indoline followed by carbonylation, [38] and by enzymatic methods. [39] Moreover, both (R)-and (S)-28 have become commercially available.…”