Atmosphere- and Solvent-Controlled Coupling and Acetylation of Phenols Induced by Visible Light

A tunable coupling or acetylation of phenol derivatives with diacetyl was enabled through the switch of the atmosphere and solvent induced by visible light under metal-free conditions. Symmetric and asymmetric diphenols or binaphthols were obtained under oxygen in water or 1,1,1,3,3,3-hexafluoroisopropanol, whereas phenol acetates were formed under argon in the presence of diacetyl and acetic acid. The possibility to control the chemo- and regioselectivities enriches the synthetic versatility of photoreactions.

Automated summary

Tunable coupling or acetylation of phenol derivatives with diacetyl was achieved by switching the atmosphere and solvent induced by visible light without metal catalyst. Symmetric and asymmetric diphenols or binaphthols were obtained under aerobic conditions in water or 1,1,1,3,3,3-hexafluoroisopropanol, while phenol acetates were formed under argon in the presence of diacetyl and acetic acid. The ability to control chemo- and regioselectivities enhances the synthetic versatility of photoreactions.