Chemo-selective couplings of anilines and acroleins/enones under substrate control and condition control

Rh(III)-catalyzed C–H activation of N-protected anilines and chemo-divergent couplings with acroleins/enones have been realized for synthesis of three classes of heterocycles. The oxidative coupling of N-pyridylaniline afforded dihydroquinolones with the acrolein being a major hydrogen acceptor. When the directing group was replaced by pyrimidyl in the same system, redox-neutral coupling occurred to afford hemiaminal ethers. Oxidative annulation of N-pyridylanilines with enones using AgBF4 oxidant afforded atropisomeric quinolinium salts.