Greening the Synthesis of 2,3‐Dihydrobenzofuran Selenides: I2/TBHP‐Promoted Selenocyclization of 2‐Allylphenols

In this work we describe the synthesis of selenium‐containing dihydrobenzofurans through the selenocyclization reaction of 2‐allylphenols. The reaction procedure uses only an I₂/TBHP oxidant system at room temperature, enabling an efficient synthesis of 2‐[(organoselanyl)methyl]‐2,3‐dihydrobenzofurans. The products are formed immediately after the addition of the oxidant system in a mixture of 2‐allylphenol and diorganyl diselenide, in the absence of solvent, at mild experimental conditions. Furthermore, control experiments were carried out, including ⁷⁷Se NMR analyses to identify intermediates, which contributed to the elucidation of the reaction mechanism.