Divergent Domino Reactions of Sulfur Ylides: Access to Functionalized Six- and Seven-Membered Nitrogen-Heterocycles.

Divergent domino annulation reactions of sulfur ylides and azadienes were developed. A wide range of functionalized benzofuran-fused six- and seven-membered nitrogen-heterocyclic compounds were prepared in moderate to excellent yields under mild conditions. It is worth noting that the crotonate-derived sulfur ylides could be used as a novel C2 synthon or C3 synthon selectively by simply transforming the base.