DMSO promoted catalyst-free oxidative C–N/C–O couplings towards synthesis of imidazoles and oxazoles

Abstract

Dimethyl sulfoxide (DMSO)-promoted catalyst-free oxidative C–N coupling and C–O coupling under oxidant-free conditions are outlined. This protocol is operationally simple and leads to various functionalized substituted imidazoles or oxazoles in good yields. To date, a very limited number of oxidation protocols have been established, where DMSO acts solely as a catalyst or an oxidant or both. In this report, DMSO is not only used as a C–N/C–O coupling agent but is also used as the oxidant required for these oxidative transformations. Hence, our demonstrated DMSO-promoted catalyst-free coupling transformation has the ability to lead to a new dimension in the field of oxidative coupling.