Regioselective Formation of Tetrahydroselenophenes via 5-exo-dig-Cyclization of 1‑Butylseleno-4-alkynes

Results on the synthesis of tetrahydroselenophene derivatives from 1-butylseleno-4-alkynes by electrophilic cyclization using iodine as the electrophilic source are presented. This methodology was carried out via a simple process under mild reaction conditions providing the cyclized products in high yields. Electrophilic sources, such as PhSeBr, CuCl2, and CuBr2, were also used in this study. The tetrahydroselenophenes obtained by this protocol were submitted to cyanation, Suzuki, and Ullmann cross-coupling reactions to afford good yields of a cross-coupled product.