Synthesis of Selenylated Dibenzo[ b,f ]oxepines from an Electrophilic Cyclization Reaction
Liliane S. de Farias, Sabrina B. Acosta, Luiz H. Dapper, Bruna R. Schneider, Angelita M. Barcellos, Liane K. Soares, Adriano B. de Oliveira, Diego Alves, Alex F. C. Flores, Gabriel P. da CostaAbstract
An efficient FeCl3-mediated intramolecular cyclization of o-alkynyl diaryl ethers with diorganyl diselenides has been developed, providing selenylated dibenzo[b,f]oxepines in good to excellent yields under mild conditions. The optimized protocol using 0.6 equiv of diorganyl diselenide and 1 equiv of FeCl3 in DCM at room temperature exhibited a broad substrate scope and high tolerance toward diverse functional groups. This approach occurs by in situ formation of an electrophilic selenium species, which undergoes a 7-endo-dig cyclization to furnish the heterocyclic core. This method provides straightforward access to functionalized dibenzo[b,f]oxepines containing selenium, a motif of interest due to its relevance in medicinal chemistry and materials science.