Stereoselective synthesis of conjugated trienes via 1,4-palladium migration/Heck sequence

Conjugated trienes are ubiquitous structures in natural products and organic functional molecules. An efficient 1,4-palladium migration/Heck sequence was developed for the highly stereoselective synthesis of trisubstituent 1,3,5-trienes, which were found to undergo easy E/Z isomerization in the presence of light.