ketone proceeded via a tandem amination (1,4-addition of aniline to an ynone and subsequent intramolecular Buchwald–Hartwig amination) to afford axially chiral N-(2-tert-butylphenyl)-2-aryl-4-quinolinone derivatives with moderate enantioselectivity (up to 72% ee).
Atroposelective Synthesis, Structure and Properties of a Novel Class of Axially Chiral
<i>N</i>
‐Aryl Quinolinium Salt
作者:Jamie S. Sweet、Sundaram Rajkumar、Paul Dingwall、Peter C. Knipe
DOI:10.1002/ejoc.202100188
日期:2021.8.6
Heterobiaryls containing a quaternized nitrogen within a chiral N−C axis occur in Nature and have been the target of several total syntheses. Here we reveal a general methodology towards enantio-enriched N-arylquinolinium salts, obtained via a four-step route from commercially available precursors and with axial stereochemistry controlled through an enantioselective ring-closing Buchwald–Hartwig coupling
A highly efficient palladium-catalyzed asymmetric synthesis of N-substituted 4-quinolones was developed via C−N coupling reaction. Various chiral quinolones were readily obtained with desirable enantioselectivity (up to 95% ee) and excellent yield (up to 99%), enabled by a simple system of palladium acetate and chiral ferrocene bisphosphine as auxiliary ligand. The corresponding racemic derivatives