Synthesis of benzocyclohepta[b]indoles by Lewis acid catalyzed annulation of two 3-(1H-isochromen-1-yl)-1H-indoles.

ABSTRACT

A novel Lewis acid catalyzed annulation reaction has been established for the synthesis of benzocyclohepta[b]indoles. This method represents a new annulation strategy to a seven-membered carbocyclic ring system from two 3-(1H-isochromen-1-yl)-1H-indole molecules using Cu(OTf)2 catalyst; moreover, the products, benzocyclohepta[b]indoles, can be used as the rapid mercuric ion colorimetric detection reagents.