Copper-catalyzed tandem synthesis of indolo-, pyrrolo[2,1-a]isoquinolines, naphthyridines and bisindolo/pyrrolo[2,1-a]isoquinolines via hydroamination of ortho-haloarylalkynes followed by C-2 arylation

Article abstract of DOI:10.1021/jo301572p

An efficient approach for the copper-catalyzed regioselective tandem synthesis of diversely substituted indolo[2,1-a]isoquinolines 11a-r, pyrrolo[2,1-a]isoquinolines 12a-d, and indolo-, pyrrolo[2,1-f ][1,6]naphthyridines 14a-f via preferential addition of the heterocyclic amines onto the ortho-haloarylalkynes over N-arylation followed by intramolecular C-2 arylation is described. The scope of the developed chemistry was successfully extended for the direct synthesis of bisindolo-, pyrrolo[2,1-a]isoquinolines 15a-g, a regioisomer of the bisindolo[1,2-a]quinolines used as organic single-crystal field-effect transistor. Hydroxymethyl benzotriazole, which is an inexpensive and air stable compound, has been used as a ligand to carry out this onestep conversion of simple, readily available starting materials into an interesting class of heterocyclic compounds.