Alkene Diversification through a Molecular Recasting Strategy Enabled by N-Heterocyclic Carbene and Photoredox Dual Catalysis.

Alkenes are fundamental structural motifs in organic synthesis, valued for their prevalence in natural products and their broad reactivity profile. While traditional de novo synthesis offers access to diverse alkene frameworks, strategies enabling the direct structural remodeling of alkenes offer more concise and efficient alternatives, yet remain underdeveloped. Herein, we present a molecular recasting strategy for alkene diversification, enabled by N-heterocyclic carbene/photoredox dual catalysis. The transformation involves a sequential dealkenylative acylation and realkenylation cascade, realizing precise and modular reassembly of a broad spectrum of alkenes under mild conditions. This approach demonstrates exceptional generality, accommodating up to trisubstituted alkenes, and supports interconversion among diverse alkene frameworks, as well as late-stage functionalization of complex bioactive molecules. Mechanistic investigations reveal a radical-mediated catalytic pathway and shed light on the synergy of photoredox and N-heterocyclic carbene dual catalysis. This work provides a conceptually different and synthetically valuable platform for alkene editing.