Synthesis of Dihydrochromeno[2,3-b]indoles via an Fe(OTf)3-Catalyzed Cascade Reaction.

A tandem cyclization between 2-(2-aminophenyl)acetonitriles and 2-(hydroxy(aryl)methyl)phenols for the preparation of dihydrochromeno[2,3-b]indole derivatives was successfully developed. The transformation proceeded smoothly in the presence of a catalytic environmentally benign iron salt, and various multisubstituted dihydrochromeno[2,3-b]indoles were synthesized in moderate to high yields.