Palladium-Catalyzed (5+3) Annulation of 4-Vinyl-4-Butyrolactones with C,N-Cyclic Azomethine Imines: Construction of Eight-Membered Ring

In this paper, we designed and synthesized 4-vinyl-4-butyrolactone as a precursor to generate the zwitterionic allylpalladium intermediates, which behaved as five-membered all-carbon synthon in palladium-catalyzed (5+3) annulation with azomethine imines, giving eight-membered ring-fused heterocycles (26 examples, 49% to 97% yield, >20:1 dr).

Automated summary

In this paper, we designed and synthesized 4-vinyl-4-butyrolactone as a precursor to generate zwitterionic intermediates, which acted as five-membered all-carbon synthons in palladium-catalyzed (5+3) annulation reactions with azomethine imines, resulting in the formation of eight-membered ring-fused heterocycles.