Enantiodivergent Steglich rearrangement of O-carboxylazlactones catalyzed by a chirality switchable helicene containing a 4-aminopyridine unit† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6sc02646j Click here for additional data file

Chirality-switchable, 4-aminopyridine-based, pseudo-enantiomeric helicenes can catalyze enantiodivergent Steglich rearrangement in up to 91% ee ( R ) and 94% ee ( S ), respectively. A pseudo-enantiomeric pair of optically switchable helicenes containing a catalytic 4- N -methylaminopyridine (MAP) bottom unit and a C 2 -symmetric, (10 R ,11 R )-dimethoxymethyl-dibenzosuberane top template was synthesized. They underwent complementary photoswitching at 290 nm ( P / M ′, 99) and 340 nm ( P / M ′, 91/9) and unidirectional thermo-rotation at 130 °C ( P / M ′, >99/