Photoredox catalysed reductive cleavage of dibenzothiophene dioxides enabled by a temperature-controlled photoreactor

Abstract

The cleavage of C–S bonds in dibenzothiophene dioxides under reductive photoredox catalysed conditions is reported. The reactions afford sulfinates, which can be used in a variety of subsequent transformations for diversification. When using unsymmetrical dibenzothiophene substrates, reductive cleavage occurs preferentially at one C–S bond. Experimental and computational studies provide insight into this interesting selectivity. The process tolerates the presence of oil (dodecane), highlighting a possible application in the removal of dibenzothiophene impurities from crude oil. The reactivity of some substrates is highly dependent on reaction temperature, hence the development of a versatile and inexpensive 3D printed photoreactor that allows for the precise control of reaction temperature is also reported.