A variety of sulfur containing scaffolds widely exists in both natural products and pharmaceuticals. There are many synthetic routes that have been developed to synthesize aryl sulfides from aryl halides, commonly using various sulfenylating reagents like N-thiosuccinimide. These methods result in a milder yet efficient conversion of simple substituted arenes to aryl sulfides, however sulfenylation via photoredox catalysis is not as widely explored. The use of photoredox allows for the generation of a more reactive radical intermediate that can be employed to generate a C-X bond, or C-S in this case. We report studies on the photocatalytic formation of C-S bonds to form benzothiazoles and sulfenylated indoles. A general Iridium (III) and Ruthenium (II) catalyzed intermolecular sulfenylation of substituted indoles, such as melatonin, has been developed using Na2S2O8 as the oxidant. The addition of a Lewis base (pyridine) affords better yields of the sulfenlyated product. This method also extends to intramolecular C-H thiolation using of substituted aromatic thioamides to form a variety of benzothiazoles.

Oxidative photo-catalyzed sulfenylation of substituted indoles and benzothiamides

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.