Phosphane‐Free Pd 0 ‐Catalyzed Cycloamination and Carbonylation with Pd(OAc) 2 and Cu(OAc) 2 in the Presence of K 2 CO 3 : Preparation of Benzocyclic Amines and Benzolactams

Phosphane‐free Pd 0 ‐catalyzed intramolecular aromatic amination was studied. o ‐Halophenethylamines and 3‐( o ‐halophenyl)propylamines were found to be transformed into indolines and quinolines in a catalytic system based on Pd(OAc) 2 and Cu(OAc) 2 in the presence of K 2 CO 3 . Application of the method to substrates containing isoquinoline rings – the 1‐( o ‐bromobenzyl)‐3,4‐dihydroisoquinolines 6 , the 1‐( o ‐bromobenzyl)‐1,2,3,4‐tetrahydroisoquinolines 7 , and the 1‐( o ‐bromophenethyl)isoquinolines 9 – provided the indolo[2,1‐ a ]isoquinoline and dibenzo[ a,f ]quinolizine ring systems 8 and 10 . Extension of the method to β‐carbolines (compounds 11 , 12 , and 17 ) produced the benz[ f ]indolo[2,3‐ a ]indolizine‐13‐ones 15 and the benz[ f ]indolo[2,3‐ a ]quinolizine 18 . The benzo[ f ]pyrido[3,4‐ a ]indolizine and indolo[ f ]pyrido[3,4‐ a ]indolizin‐12‐one ring systems 27 and 31 were built in a similar manner. It was also found that under an atmosphere of CO the same catalytic system produced the corresponding benzolactams, the isoquino[2,1‐ a ][2,7]naphthyridine 34 and the indolo[2,3‐ a ]pyrido[ g ]quinolizin‐8‐one 36 [(±)‐dihydronaucléfine] in good yields.