A Rare Alder-ene Cycloisomerization of 1,6-Allenynes.
Liam M JoyceMelanie A DrewAndrew J TagueThanaphat ThaimaAli GouranourimiAlireza AriafardStephen G PyneChristopher J T HylandPublished in: Chemistry (Weinheim an der Bergstrasse, Germany) (2022)
Thermally induced cycloisomerization reactions of 1,6-allenynes gives α-methylene-γ-lactams via intramolecular Alder-ene reactions. The mechanism is supported by computational and deuterium labelling studies. This thermal, non-radical method enables the discovery of a hitherto unknown route that proceeds via a divergent mechanism distinct from the previous [2+2] cycloisomerization manifold.