Nickel-Catalyzed Quinoline Synthesis through Skeletal Editing Strategy Using Calcium Carbide as an Inorganic C2 Source

Benzo[c]isoxazoles serve as versatile precursors for the skeletal editing of heterocyclic frameworks, wherein calcium carbide, as an inorganic C2 source, participates in C-O/N-O bond cleavage and concurrent C-C/C-N bond formation through molecular surgery. Diverse 3-substituted quinolines and 3,4-disubstituted quinolines were efficiently obtained via nickel-catalyzed one-pot three-component reactions using inexpensive, easy-to-handle solid calcium carbide as a substitute for flammable and explosive gaseous acetylene, and benzo[c]isoxazoles and organic boronic acids as commercially available starting materials. This strategy exhibits a broad substrate scope, high efficiency, simple workup procedures, and gram-scale applicability. These advantages underscore the unique role of calcium carbide in enabling skeletal editing for streamlined synthesis.