Asymmetric Two-component Alkenyl Catellani Reaction for the Construction
of C--N Axial Chirality
Abstract
Herein we report an asymmetric two-component alkenyl Catellani reaction
for the construction of C–N axial chirality through a pal-ladium/chiral
norbornene cooperative catalysis and an axial-to-axial chirality
transfer process. Various partially aromatic iodinated 2-pyridones,
quinolones, coumarin and uracil substrates react with 2,6-disubstituted
aryl bromides with a tethered amide group, to afford a wide variety of
polycyclic C–N atropisomers (38 examples, up to 97% e.e.). The
obtained C–N axial chirality is originated from the preformed transient
C–C axial chirality with high fidelity. The synthetic utility of this
chemistry is demonstrated by facile preparation of complex quinoline and
pyridine based C–N atropisomers through a N-deprotection and
aromatization sequence. In addition, a remote axial-to-central
diastereoinduction process dictated by C–N axial chirality is observed
with excellent diastere-ocontrol.