Alkene versus alkyne reactivity in unactivated 1,6-enynes: regio- and chemoselective radical cyclization with chalcogens under metal- and oxidant-free conditions

Substituted pyrrolidine derivatives are obtained via regio- and chemoselective 5-exo-dig radical cyclization of unactivated 1,6-enynes with chalcogens under metal- and oxidant-free conditions.