Stereoselective synthesis of 1,3,5-trienes from alkynones and allyl carbonyl compounds through C-C σ-bond cleavage under transition-metal-free conditions

An atom-economical transition-metal-free protocol for the stereoselective synthesis of conjugated trienes has been developed. These transformations were realized through base promoted C-C σ-bond cleavage reactions of allyl carbonyl compounds. This methodology efficiently constructs a broad range of conjugated trienes with the advantages of mild reaction conditions, low cost and operational simplicity.