Harnessing solvent–3O2 charge transfer complex for photochemical conversion of phosphines to phosphine oxides: the synergy of light and ambient air

Abstract

The development of “zero-additive” synthetic protocols is the primary objective of modern green chemistry. Herein, we report a remarkably simple and robust catalyst-free and photosensitizer-free aerobic oxidation of a diverse range of tertiary phosphines to their corresponding phosphine oxides. This transformation is driven by near-UV light irradiation at room temperature, utilizing ambient air as the sole oxidant. Notably, the reaction proceeds with excellent yields in a green solvent, eliminating the need for toxic transition-metal catalysts, expensive organic dyes, or hazardous solvents. This methodology circumvents the traditional kinetic barriers of oxygen activation through a solvent–³O₂ charge-transfer pathway facilitated by the precise wavelength of the light source. The combination of high atom economy, the use of benign reagents, and a simplified purification process makes this protocol an ideal, eco-friendly alternative for both academic and industrial applications.