Metal-free hydrogenation of viologens to piperidine derivatives for bacterial inhibition (opens in new tab)

The hydrogenation of aromatic viologens to their non-aromatic derivatives holds promise for biomedical and materials science applications. Conventional hydrogenation methods, however, rely on harsh reductants and high-cost metal catalysts. Here we report a safe, metal-free hydrogenation strategy that uses formic acid as a sustainable reductant, facilitated by an azeotropic mixture with N,N-dimethylformamide. This method enables the efficient conversion of diverse viologen derivatives into the...