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Synthesis of ferrocenyl quinones and ferrocenyl based burning rate catalysts

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2003
Açıkalın, Serdar
Recently, considerable interest has been devoted to the synthesis of new ferrocene derivatives since properly functionalized ferrocene derivatives could be potential antitumor substances. For this purpose, we have investigated the synthesis of ferrocenyl quinones starting from squaric acid. Thermolysis of ferrocenylsubstituted cyclobutenones, which have been prepared from ferrocenyl cyclobutenediones and alkenyllithiums, affords hydroquinones, which furnish, upon oxidation, ferrocenyl quinones. Ferrocenyl cyclobutenediones have been prepared from known cyclobutenediones by nucleophilic addition of ferrocenyllithiumfollowed by hydrolysis, Pd/Cu-cocatalyzed cross-coupling with (tri-n-butylstannyl)ferrocene or FriedelاCrafts alkylation with ferrocene. A mechanism involving electrocyclic ring opening of alkenyl substituted cyclobutenone to dienylketene and consequent electrocyclic ring closure to cyclohexadienone followed by enolization has been proposed to account for the formation of ferocenyl substituted hydroquinones. Rocket design and production is one of the hottest topics in defense industry. On this subject, significant amount of investments have been done and excellent results were obtained. Among the burning rate catalysts for composite rocket propellants, ferrocene derivatives are one of the most famous ones. Although ferrocene derivatives are superior to some other burning rate catalysts, their use has some drawbacks arising from the tendency of migration in the bulk of the material and their sensitivity toward oxidation by air. With the aim of preventing the negative aspects of ferrocene derivatives, we have investigated the synthesis of EDA (ethylenediamine), TEP (tetraethylenepentamine) and DDI (dimeryl-diisocyanate) based ferrocene derivatives.