Rhodium-Catalyzed Synthesis of Isoquinolines and Indenes from Benzylidenehydrazones and Internal Alkynes

A new route is presented for the selective assembly of isoquinolines and indenes by rhodium-catalyzed tandem cyclization of benzylidenehydrazones with internal alkynes. This method involves the selective cleavage of the N–N bond and the C═N bonds and is dependent on the substituents of the benzylidenehydrazone.