Site-selective addition of succinimide motif through nitro-assisted C-H functionalization of (hetero) arenes under rhodium catalysis.

Succinimide motifs are recognized as privileged cores in anticonvulsants and antipsychotics such as phensuximide, ethosuximide, and lurasidone. These succinimides can be readily converted into pharmaceutically important pyrrolidines and γ-lactam scaffolds, making them highly promising compounds in drug discovery. Nitroarenes are also important chemical feedstocks and have attracted increased attention owing to their versatile applications in pharmaceuticals, functional materials, and agricultural pharmacology. Therefore, directly combining succinimides with nitroarenes is a valuable approach for efficiently constructing novel succinimide-linked nitroarene frameworks. We herein report the site-selective addition of the succinimide scaffold to various nitroarenes via nitro-directed ortho-C-H alkylation using maleimides under rhodium(III) catalysis. The versatility of the developed protocol is demonstrated through nitro-group reduction, reductive cyclization of the synthesized products, and selective modifications of the succinimide framework. Mechanistic studies, including deuterium-labeling and kinetic isotope effect experiments, helped elucidate a plausible reaction mechanism.