Visible-Light-Promoted Synthesis of Vinyl Aryl Sulfides with Enhanced Fluorescent Properties

Vinyl systems, particularly those functionalized with sulfur, exhibit environment-sensitive fluorescence and potential applications in fluorescent sensors and optoelectronic materials. This work describes a sustainable methodology applying visible-light source in the achievement of trisubstituted vinyl aryl sulfides. After reaction optimization, DMSO, thiophenol, and a 2 h reaction time were identified as the optimal conditions, affording product 3a in 70% of yield. The protocol was applied to diarylacetylenes 1a-d and p-substituted thiols 2a-c, providing six derivatives in 62-80% yields. The studies conducted showed that derivatives 3a-f retained near-UV absorption while displaying well-defined blue-green emission, larger Stokes shifts, and enhanced fluorescence quantum yields, with derivative 3c showing the highest emissive efficiency. These results demonstrate that the visible-light protocol affords fluorescent sulfur-containing derivatives for optoelectronic materials.