Catalytic Dienylation: An Emergent Strategy for the Stereoselective Construction of Conjugated Dienes and Polyenes

Abstract Stereoselective construction of conjugated dienes and polyenes has remained an enduring synthetic problem owing to the central roles these compounds play in natural product synthesis, methodology, and medicine. This review focuses on recent developments in dienylation as an emerging strategy for the direct installation of unsaturated four-carbon units of conjugated π-systems, outlining the regio- and stereoselectivity, as well as the synthetic scope of reactions with various dienylating reagents and the mechanistic implications of the catalytic cross-coupling processes that are used to enable dienylation. 1 Introduction 2 Sulfolenes 3 1,3-Dienes 4 Small-Ring Dienylation Reagents 5 Pyrones, Alkynes, and Homoallenylboronates 6 Conclusion and Outlook