Enantioselective Synthesis of Axially Chiral Figure-Eight Spirocycloparaphenylenes via Rh-Catalyzed Intermolecular [2 + 2 + 2] Cycloaddition
Li‐Hsiang Wang, Juntaro Nogami, Yuki Nagashima, Ken Tanaka
Abstract
We have achieved the enantioselective synthesis of axially chiral figure-eight spiro[9.9]cycloparaphenylene (CPP) tetracarboxylates with up to 75:25 er via the cationic Rh(I)/( R )-H 8 -BINAP complex-catalyzed chemo-, regio-, and enantioselective intermolecular double [2 + 2 + 2] cycloaddition of an achiral symmetric tetrayne with dialkyl acetylenedicarboxylates followed by reductive aromatization. The spiro[9.9]CPP tetracarboxylates are highly distorted at the phthalate moieties with large dihedral and boat angles and exhibit weak aggregation-induced emission enhancement behavior.
Topics & Concepts
Enantioselective synthesisCycloadditionChemistryCationic polymerizationIntermolecular forceCatalysisRhodiumStereochemistryMedicinal chemistryPolymer chemistryOrganic chemistryMoleculeSynthesis and Properties of Aromatic CompoundsAxial and Atropisomeric Chirality SynthesisCyclization and Aryne Chemistry