98% ee using a strong Brønsted acid as the activator. This methodology was applied in the facile synthesis of biologically active products containing a chiral indoline skeleton. The mechanism of Pd-catalyzed asymmetric hydrogenation was investigated as well. Isotope-labeling reactions and ESI-HRMS proved that an iminium salt formed by protonation of the C═C bond of indoles was the significant intermediate
Quite a pair: The first organocatalytic directasymmetric reduction of unprotected 1H‐indoles to chiral indolines has been developed. The reaction proceeds through the generation of electrophilic indolenium ions by a Brønsted acid, and then chiral Lewisbase (1) mediated enantioselective hydride transfer with HSiCl3. A variety of chiral indolines were obtained with moderate to excellent enantioselectivity
introduced as catalysts for the intramolecular hydroamination reaction of unactivated aminoalkenes. The catalysts show high activity in the construction of pyrrolidines, which are accessed with excellent optical purity. Enantiomerically enriched piperidines and indolines are also produced, and various functional groups are tolerated with this LTM system. A reaction mechanism is proposed, and a major