Divergent Coupling of Anilines and Enones by Integration of C@H Activation and Transfer Hydrogenation.

Cp*Rh^III/Ir^III complexes are known to play important roles in both C@H activation and transfer hydrogenation (TH). However, these two areas evolved separately. They have been integrated in redox- and chemodivergent coupling reactions of N-pyridylanilines with enones. The iridiumcatalyzed coupling with enones leads to the efficient synthesis of tetrahydroquinolines through TH from ⁱPrOH. Counterintuitively, iPrOH does not serve as the sole hydride source, and the major reaction pathway involves disproportionation of a dihydroquinoline intermediate, followed by the convergent and iterative reduction of quinolinium species. [ABSTRACT FROM AUTHOR]