Binaphthol derivatives as catalysts for visible light induced aryl halide derivatizations

Abstract

Derivatizations of aryl halides are important reactions for the construction of diverse aromatic compounds, and photocatalysis is becoming a mild and efficient way for aryl halide derivatizations. Binaphthol derivatives are promising photocatalysts due to their notable photoresponse originating from their large conjugate skeletons. The enhanced reducibility of the excited phenolate anions and reversible process of gain and loss of electrons make it possible to use binaphthol derivatives for photocatalytic reduction reactions. Herein, a visible light responsive binaphthol derivative Me₄L–OH and the corresponding metal–organic framework Zr-MOF-OH are utilized for photocatalytic aryl halide derivatizations. Phenoxy anions in binaphthol derivatives show high reducing capacity, remarkable activity, good selectivity and fair compatibility towards the activation of aryl halides through a single-electron transfer process under white light irradiation and alkaline conditions. The generated aryl radicals could undergo biaryl cross-coupling, hydrodehalogenation, borylation, and thioetherification to afford a series of functionalized aromatic compounds.