Unconventional Reactivity with DABCO-Bis(sulfur dioxide): C-H Bond Sulfenylation of Imidazopyridines

This work highlights the unexpected and unprecedented outcome of the reactivity with DABCO-bis(sulfur dioxide). The use of this reagent led to the exclusive introduction of a sulfur atom on the C-3 position of imidazopyridines instead of a sulfone group. The reaction methodology turned out to be robust, scalable and suitable for various imidazopyridines and aryl iodides both bearing substituents with different electronic and steric properties (38 examples). Beyond the fact that this synthetic method complements the previously reported protocols for sulfenylation reactions, this work is meant to underline the unconventional role of DABCO-bis(sulfur dioxide).