Sustainable photoredox chemistry of a transient ternary complex: an unconventional approach toward trifluoromethylated hydroquinones

A distinctive sustainable approach has been developed to afford highly functionalized CF3-hydroquinone derivatives as potent biologically active molecules. The synthetic protocol involves the photoirradiation of a mixture of easily accessible benzoquinones and CF3SO2Na. This process generates a quinhydrone charge-transfer complex of benzoquinone and its in situ generated hydroquinone in the presence of a small amount of hydrogen donors, more preferably water. The subsequent formation of a transient ternary complex involving CF3SO2Na elicits photoinduced charge-transfer (CT), thereby producing CF3-hydroquinones. The present method is highly practical and atom-economical whilst avoiding the use of any sacrificial electron donors. Furthermore, the unique ternary complex intermediate permits site-selective three-component trifluoromethylation in the presence of vinyl arenes.

Automated summary

A sustainable method has been developed to synthesize highly functionalized CF3-hydroquinone derivatives, which exhibit potent biological activity. The approach involves photoirradiation of a mixture containing readily available benzoquinones and CF3SO2Na, resulting in the generation of CF3-hydroquinones through photoinduced charge-transfer reactions. This method is practical, atom-economical, and enables site-selective three-component trifluoromethylation in the presence of vinyl arenes.