| Summary: | Benzo[1,2-d;4,5-d′]bis[1,3]dithioles are important building blocks within a range of functional materials such as fluorescent dyes, conjugated polymers, and stable trityl radicals. Access to these is usually gained via <i>tert</i>-butyl aryl sulfides, the synthesis of which requires the use of highly malodorous <i>tert</i>-butyl thiol and relies on S<sub>N</sub>Ar-chemistry requiring harsh reaction conditions, while giving low yields. In the present work, S-<i>tert</i>-butyl isothiouronium bromide is successfully applied as an odorless surrogate for <i>tert</i>-butyl thiol. The C-S bond formation is carried out under palladium catalysis with the thiolate formed in situ resulting in high yields of <i>tert</i>-butyl aryl sulfides. The subsequent formation of benzo[1,2-d;4,5-d′]bis[1,3]dithioles is here achieved with scandium(III)triflate, a less harmful reagent than the usually used Lewis acids, e.g., boron trifluoride or tetrafluoroboric acid. This enables a convenient and environmentally more compliant access to high yields of benzo[1,2-d;4,5-d′]bis[1,3]dithioles.
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