Stereoselective Route to Nitrogen-Substituted Polarized Trienes and [3]Dendralenes

Acyclic conjugated polyenes represent a privileged scaffold with substantial potential for synthesizing complex molecular architectures. Traditional de novo synthesis of these molecules often encounters regio- and stereoselectivity challenges, resulting in multistep processes that compromise reaction efficiency. In this study, we introduce a modular approach for the direct synthesis of nitrogen-substituted polarized conjugated trienes and [3]dendralene derivatives from readily available feedstock reagents, including alkenyl triflates, boronates, and ynamides. This transformation is particularly notable for its 1,3-alkenyl migration, showcasing an Umpolung reactivity. Moreover, it enables the rapid diversification of synthetically challenging triene motifs and [3]dendralenes, demonstrating broad functional group compatibility and facilitating the synthesis of conjugated and cross-conjugated hybrid molecules. Mechanistic insights are supported by control experiments and DFT calculations, highlighting the robustness and versatility of our methodology in advancing the field of conjugated polyene synthesis.