Arylacetylenes as two-carbon synthons: synthesis of eight-membered rings via C≡C bond cleavage.

The first synthesis of eight-membered N-containing heterocycles by oxidative bicyclization/ring extension of arylacetylenes and aryl amines has been achieved. This protocol uses arylacetylene as an unusual two-carbon synthon by incorporating the two parts of the cracked C≡C bond into the final product, which provides a new method for using arylacetylenes as two-carbon synthons and further enriches C≡C bond cleavage methodology. Moreover, this multi-component reaction can provide diverse fused elegant eight-membered N-heterocycles under mild conditions with wide substrate scopes. [ABSTRACT FROM AUTHOR]