Polymethylated [Fe(eta(6)-arene)(2)](2+) dications: methyl-group rearrangements and application of the EINS mechanism

0360469 - ÚACH 2012 RIV GB eng J - Journal Article
Štíbr, Bohumil - Bakardjiev, Mario - Hájková, Zuzana - Holub, Josef - Padělková, Z. - Růžička, A. - Kennedy, J.D.
Polymethylated [Fe(eta(6)-arene)(2)](2+) dications: methyl-group rearrangements and application of the EINS mechanism.
Dalton Transactions. Roč. 40, č. 22 (2011), s. 5916-5920. ISSN 1477-9226. E-ISSN 1477-9234
R&D Projects: GA MŠMT LC523
Institutional research plan: CEZ:AV0Z40320502
Keywords : electrophile-induced nucleophilic substitution
Subject RIV: CA - Inorganic Chemistry
Impact factor: 3.838, year: 2011

Reactions between the methylated arenes ArMen [where ArMen = C6MenH(6-n), and n = 1-6] and FeCl2 in heptane at 90 degrees C in the presence of anhydrous AlCl3 give, for the arenes with n = 1-5, extensive isomerisations and disproportionations involving the methyl groups on the arene rings, and the formation of mixtures of [Fe(ArMen)(2)](2+) dications that defy separation into pure species. GC-MS studies of AlCl3/mesitylene and AlCl3/durene reactions in the absence of FeCl2 (90 degrees C, 2 h) allow quantitative assessments of the rearrangements, and the EINS mechanism (electrophile-induced nucleophilic substitution) is applied to rationalise the phenomena. By contrast, ArMen/FeCl2/AlCl3 reactions in heptane for 24-36 h at room-temperature proceed with no rearrangements, allowing the synthesis of the complete series of pure [Fe(ArMen)](2+) cations in yields of 48-71%.
Permanent Link: http://hdl.handle.net/11104/0198016