Axially Chiral Naphthalol Benzo‐Quinoline Ligands for the Cu(OTf) 2 ‐Catalyzed Enantioselective Cyclopropanation of α‐Arylidene Diazosuccinimides and Styrenes

Abstract A new class of axially chiral arylphenol‐quinoline ligands was designed and prepared from commercially available 2′‐amino[1,1′‐binaphthalen]‐2‐ol (NOBIN) and 2‐amino‐2′‐hydroxy‐5,5′,6,6′,7,7′,8,8′‐octahydro‐1,1′‐binaphthyl (H 8 ‐NOBIN). Of these ligands, L1 combined effectively with Cu(OTf) 2 to catalyze the cyclopropanation reactions of α‐arylidene diazosuccinimides and styrenes. Consequently, the desired multifunctional products bearing untouched arylidene groups were obtained in moderate‐to‐excellent enantioselectivities (≤96 : 4 er ) and diastereoselectivities (≤95 : 5 dr ) with moderate‐to‐good yields (≤83 %). After simple recrystallization, the diastereoselectivities and enantioselectivities of the chiral products were considerably improved (≥99 : 1 er with >99 : 1 dr ) in most cases. This approach provides an efficient solution for the preparation of high‐optical‐purity multifunctional α‐arylidene spirocyclopropane succinimides, potentially valuable as chiral synthons and platform molecules which may be transformed into diverse functional chiral molecules by reaction at different functional sites.