Palladium‐Catalyzed [4 + 4] Cycloaddition of Homo‐TMM All‐Carbon 1,4‐Dipole Precursors for Construction of Benzofuro[3,2‐b]azocines and Furo[3,2‐b]azocines

Abstract

Comprehensive SummaryWe developed a novel Pd‐catalyzed [4 + 4] cycloaddition of (benzo)furan‐derived azadienes with homo‐TMM all‐carbon 1,4‐dipoles in situ generated from α‐allyl malonate derivatives, affording an array of benzofuro[3,2‐b]azocines and furo[3,2‐b]azocines with good to excellent yields (up to 96%) and exclusive regioselectivities. This methodology featured mild reaction conditions and good functional group tolerance. The synthetic utility was demonstrated by a gram‐scale reaction. Furthermore, the catalytic asymmetric [4 + 4] cycloaddition version has also been explored.