Three-Component Ring-Expansion Reaction of Indoles Leading to Synthesis of Pyrrolo[2,3- c ]quinolines.

Herein, we have developed an atom- and step-economic three-component cascade reaction that enables a modular platform for the synthesis of pyrrolo[2,3- c ]quinoline compounds through ring-expansion/cyclization by way of novel N1-C2 cleavage of indoles. The metal-free catalytic system exhibits a broad functional group tolerance.