Development of a Brønsted acid-promoted arene-ynamide cyclization toward the total syntheses of marinoquinolines A and C and aplidiopsamine A.

A Brønsted acid-promoted arene-ynamide cyclization has been developed to construct the 3H-pyrrolo[2,3-c]quinolines. This reaction consists of the generation of a highly reactive keteniminium intermediate from arene-ynamide activated by a Brønsted acid and electrophilic aromatic substitution reaction to give arene-fused quinolines in high yields. This methodology enabled facile access to marinoquinolines A and C and aplidiopsamine A.