Deoxygenation of heterocyclic N-oxides employing iodide and formic acid as a sustainable reductant
Autores. Alicia Elvira Cruz-Jiménez, Paola Alejandra Argumedo-Castrejón, Jeferson B. Mateus-Ruiz, Victor A. Lucas-Rosales, Octavio Adrián Valle-González, J. Oscar C. Jiménez-Halla, J. Armando Luján-Montelongo
Revista. New Journal of Chemistry
https://doi.org/10.1039/D4NJ00913D
Resumen. We present a novel deoxygenation method for heterocyclic N-oxides utilizing iodide as a catalyst. Iodide acts as a reducing catalyst that is regenerated by formic acid, which also serves as a Brønsted activator and solvent. The method demonstrates high efficiency and excellent selectivity in the reduction of a variety of heterocyclic N-oxides and tertiary amines. Our computational DFT investigation revealed that the reduction mechanism entails a direct interaction between iodide and the oxygen of the N-oxide within a Mg2+/formic acid framework, resulting in the formation of the N-heterocycle and the release of a hypoiodite unit. Additionally, a molecular mechanism for the regeneration of iodide from hypoiodite, facilitated by formic acid, is suggested. This method provides an environmentally friendly approach for the deoxygenation of N-oxides and related species.