Asymmetric Construction of Axially Chiral 2-Arylpyrroles by Chirality Transfer of Atropisomeric Alkenes.

ABSTRACT

Axially chiral 2-arylpyrrole frameworks are efficiently accessed through a direct chirality transfer strategy by rapid cyclization of enantioenriched atropisomeric alkenes, which are generated by organocatalytic asymmetric N-alkylation reactions. This approach accommodates a broad scope of substrates with remarkably high chirality transfer efficiency, affording novel atropisomers with a fully substituted pyrrole moiety and high enantiopurities. Given the enantioenriched atropisomeric alkenes, novel heterocyclic 2-arylazepine atropisomers were realized through a rationally designed ene reaction.