1,7‐Octadiene‐Assisted Tandem Multicomponent Cross‐Enyne Metathesis (CEYM)‐Diels–Alder Reactions: A Useful Alternative to Mori’s Conditions

The use of 1,7‐octadiene as an in situ source of ethylene led us to develop a novel multicomponent tandem cross‐enyne metathesis (CEYM)‐Diels–Alder reaction. The process can be considered a relay metathesis, in which the ethylene liberated in the ring‐closing metathesis (RCM) of 1,7‐octadiene initiates the tandem sequence. Aliphatic, aromatic, and fluorinated alkynes and several dienophiles are compatible with the process, which is particularly efficient with aromatic alkynes. This methodology constitutes a useful variant of Mori’s conditions in CEYM‐related reactions.