Utilization of Cooperative Ni Catalyst for Selective Transfer Hydrogenation of N-Heteroarenes with Minimal Hydrogen Surrogate

Herein, an air-stable cooperative Ni(II)-NNN catalyst (<b>1</b>) bearing a bis(2-hydroxy pyridine) ligand was synthesized for the selective transfer hydrogenation of quinoline derivatives to 1,2,3,4-tetrahydro derivatives utilizing minimal loading of Me₂NHBH₃ as a hydrogen surrogate via a borylated product intermediate. Mechanistic studies include the identification of catalytically relevant deprotonated intermediate <b>1a</b>, which sheds light on the hydride and proton transfer to the quinoline derivatives via the participation of the functionalized protic ligand arm.