Bromide-Catalyzed Remote C-H Selenylation of Naphthalenes toward Selenylated Naphthalenes

Direct C-H functionalization can rapidly strengthen functional molecules and provide useful structural complexity. Great achievements have been accomplished for ortho- and meta-C-H bond functionalization of arenes. Comparatively, direct para-C-H bond functionalizations via multicomponent reactions under metal-free conditions remain elusive. Here, we report a robust strategy for aromatic C-H selenylation via bromide catalysis that does not require directing groups or transition metals, providing a series of arylselenylated naphthalenes with high efficiency. Additionally, commercially available Se powder and boronic acids are employed as the selenyl source, and DMSO acts as both the solvent and oxidant in this reaction, which eliminates the need for toxic diselenide and strong chemical oxidants. Control experiments reveal that bromide and DMSO play key roles in this transformation. The potential synthetic utility is further demonstrated by synthetic transformations and scale-up reactions. Preliminary mechanistic experiments indicate that this transformation possibly proceeds via a radical pathway.