A New Route to 1,3-bis-Exocyclic Dienes Using a Palladium-mediatedCyclization/Coupling Reaction of Conjugated Enynes with Organic Halides and Triflates
A New Route to 1,3-bis-Exocyclic Dienes Using a Palladium-mediatedCyclization/Coupling Reaction of Conjugated Enynes with Organic Halides and Triflates
The palladium catalyzed tandem cyclization/coupling reaction of conjugated enynes having a stabilizing carbon nucleophile with unsaturated halides or triflate afforded stereodefined functionalized 1,3-bis-exocyclic dienes. Moderate yields were obtained with substrates of type 1. However, higher homologs of type 2 led to the formation of functionalized 1,3-bis-exocyclic dienes and hexatrienes in good yields. An initial study on the sequential cyclization/coupling reaction/electrocyclization in a one-pot procedure leading to cyclohexadienes is also presented.