73635-55-9Relevant academic research and scientific papers
Transition-Metal-Diene Complexes in Organic Synthesis, 12 +"--"+ Regio- and Stereoselectivity of Electrophilic Substitutions of Arylamines by Tricarbonyliron-Complexed Cyclohexadienylium Cations and Oxidative Cyclizations to Carbazoles
Knoelker, Hans-Joachim,Bauermeister, Michael,Pannek, Joern-Bernd
, p. 2783 - 2794 (2007/10/02)
Electrophilic substitutions of donor-substituted arylamines using tricarbonyliron-complexed cyclohexadienylium cations lead regio- and stereoselectively to the corresponding tricarbonylcyclohexadieneiron complexes.The C-C bond formation occurs regioselectively in the ortho position with respect to the amino group with arylamines containing a substituent in the para position.The initially formed N-alkylated arylamine (kinetic product) is shown to rearrange in an intermolecular process to the C-alkylated arylamine (thermodynamic product).The reported oxidative cyclization to the 3-methylcarbazole yields large amounts of the demetalated ligand.However, oxidative cyclization to the 3-methoxycarbazole is possible under mild reaction conditions (room temperature) by using especially activated manganese dioxides. Key words: Cylohexadienylium ligands / Substitutions, electrophilic / Cyclohexadiene ligands / Cyclizations, oxidative / Carbazoles / Iron complexes
Organometallic Complexes in Synthesis. Part 16. Reactions of Tricarbonyl(cyclohexadienyl)iron (1+) Salts with Aromatic Amines.
Birch, Arthur J.,Liepa, Andris J.,Stephenson, G. Richard
, p. 713 - 718 (2007/10/02)
Tricarbonyl(cyclohexadienyl)iron(1+) salts of the type (1) cause C- or N-alkylation of aromatic amines depending on the conditions used.The best procedure involves formation of the salt in situ from an alkoxy-complex in the presence of a small proportion of acid.Attempts to extend the reaction to alkylate 6-amino-5,8-dimethylisoquinoline, to obtain an intermediate for the synthesis of ellipticine, resulted, instead, in irreversible alkylation at the pyridine nitrogen.
