Copper-catalyzed regioselective 1,4-sulfonylcyanation of 1,3-enynes with sulfonyl chlorides and TMSCN

Abstract

A novel and practical copper-catalyzed reaction for the 1,4-sulfonylcyanation of 1,3-enynes under mild conditions is described. This protocol provides efficient and straightforward access to a variety of 5-sulfonylpenta-2,3-dienenitrile derivatives with excellent functional group tolerance and good regioselectivity from readily available 1,3-enynes and commercially available sulfonyl chlorides and TMSCN. A mechanism involving sulfonyl and allenyl radical species is proposed.