Nickel-Catalyzed Site-Selective C3–H Functionalization of Quinolines with Electrophilic Reagents at Room Temperature

Herein, we disclose a mild and versatile nickel-catalyzed method for exclusive C3-selective thioetherification, alkylation, arylation, acylation, and phosphorylation of quinolines with a variety of electrophiles. Unactivated quinolines can be functionalized without directing groups at room temperature. Control experiments indicated that quinolines underwent 1,4-addition with nickel hydride species generated from β-H elimination of alkyl nickel intermediates to produce 1,4-dihydroquinolines, which further went through subsequent nucleophilic attack to external electrophiles and oxidative aromatization to generate C3–H-functionalized products.