Modulation of Excited-State Reactivity of o -Nitroaryl Alkynes via Solvent Effects: Toward Controllable Synthesis of o -Aminobenzoic Acid and Benzoxazinone Derivatives

-nitroaryl alkynes is reported for the divergent synthesis of two anthranilic acid derivatives. Upon photoexcitation, the nitro group reaches its triplet excited state and undergoes an intramolecular cyclization with the adjacent alkyne. The reaction pathway is dictated solely by the solvent: polar protic solvents afford ring-opened orthobenzamide carboxylates, whereas nonpolar solvents favor fused heterocycles.This metal-free method features a 100% atom economy, broad substrate scope, and high yields.