Induction of Axial Chirality in 8-Arylquinolines through Halogenation Reactions Using Bifunctional Organocatalysts

5 years ago

Induction of Axial Chirality in 8-Arylquinolines through Halogenation Reactions Using Bifunctional Organocatalysts

Keisuke Asano, Seijiro Matsubara, Ryota Miyaji

The enantioselective syntheses of axially chiral heterobiaryls were accomplished through the aromatic electrophilic halogenation of 3-(quinolin-8-yl)phenols with bifunctional organocatalysts that control the molecular conformations during successive halogenations. Axially chiral quinoline derivatives, which have rarely been synthesized in an enantioselective catalytic manner, were afforded in moderate-to-good enantioselectivities through bromination, and an analogous protocol also enabled enantioselective iodination. In addition, this catalytic reaction, which allows enantioselective control through the use of mono-ortho-substituted substrates, allowed the asymmetric synthesis of 8-arylquinoline derivatives bearing two different halogen groups in high enantioselectivities. Bifunctional catalysis: The enantioselective syntheses of axially chiral heterobiaryl compounds are accomplished through the aromatic electrophilic halogenation of 3-(quinolin-8-yl)phenols with bifunctional organocatalysts to control the molecular conformations during successive halogenation reactions. Axially chiral quinoline derivatives, which have rarely been synthesized in an enantioselective catalytic manner, are afforded through bromination and iodination reactions. In addition, this protocol, which controls the reaction enantioselectivity through the use of mono-ortho-substituted substrates, also enables the synthesis of 8-arylquinolines bearing two different halogen groups in high enantioselectivity.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201701707