Reductant-Free NiF ₂ /Picolinic Acid-Catalyzed Coupling–Cyclization of 2-Iodobenzamides with Malonates

High Resolution Image Download MS PowerPoint Slide A ligand-enabled NiF 2 /picolinic acid catalyst system enabled an efficient and chemoselective coupling–cyclization of ortho -halo benzamides, including ortho -iodo- and ortho -bromobenzamides, with malonates or 1,3-diketoesters to furnish homophthalimides under operationally simple conditions. The reaction proceeded with high selectivity for the activation of benzamide-proximal aryl halide (C–I or C–Br) while tolerating additional aryl C–Br functionality at other positions, which remained intact throughout the transformation. Broad functional-group tolerance was observed across both benzamide and nucleophile classes, delivering the desired products in consistently high yields. Control experiments were consistent with the involvement of a redox-assisted nickel catalytic cycle. This cost-effective strategy provided a general and practical approach for constructing homophthalimide frameworks from readily accessible substrates.