Synthesis of ferrocenylidene cyclopentenediones

Download
index.pdf
2005
Köktürk, Mustafa
Show full item record
178
views
52
downloads
2-Arylidine-4-cyclopentene-1,3-diones are known to be antitumor agents. Incorporation of the essential structures of such compounds with a ferrocene moiety instead of an aryl group could provide subtances with enhanced antitumor activities since some ferrocene derivatives have already proved to be active against a number of tumors. Thus, we have investigated the squarate-based synthesis of 2-ferrocenylidene-4-cyclopentene-1,3-diones. Upon thermolysis, 4-hydroxy-4-ferrocenylethynyl-2-cyclobutenones, prepared from 3-cyclobutene-1,2-diones and lithioethynylferrocene, produced exclusively 2-ferrocenylidene-4-cyclopentene-1,3-diones. In some cases, ferrocenyl quinone derivatives are obtained in very minor amounts. Moreover, the heating of a mixture of 4-ferrocenylethynyl-4-hydroxy-2-cyclobutenones and silica gel in oven at 120 oC without using any solvent provided the same type of products. More importantly, the stirring of a solution of 4-ferrocenylethynyl-4-hydroxy-2-cyclobutenone (37A-C) derivatives in ethyl acetate at the room temperature yielded the same type products, as well. It appears that 4-hydroxy-4-ferrocenylethynyl-2-cyclobutenones are more reactive than corresponding phenyl analogs. For the formation of ferrocenyl-substituted cyclopentenediones, a mechanism involving first electrocyclic ring opening of ferrocenylethynyl-substituted cyclobutenones to corresponding ketene intermediate and then ring closure, has been proposed. The exclusive formation of cyclopentenediones is attributed to the radical stabilizing ability of the ferrocenyl moiety during the course of the reaction.
Chemistry, Organic
http://etd.lib.metu.edu.tr/upload/12606316/index.pdf
https://hdl.handle.net/11511/15240
Graduate School of Natural and Applied Sciences, Thesis

Suggestions

Synthesis of 5-ferrocenyl-4-((4-nitrophenyl)sulfenyl)-1H-pyrazoles by electrophilic cyclization
Karahan Dağ, Fulya; Zora, Metin; Department of Chemistry (2011)
Pyrazoles have been intensely studied in the design and synthesis of biologically active agents because they display considerable medicinal activities. Recent studies have shown that integration of a ferrocenyl unit with structural features of pyrazoles can result in the formation of the new products with enhanced or/and unexpected biological activity since several ferrocene derivatives have already been illustrated to be active against a number of tumors. Therefore, we have investigated the electrophilic c...
Synthesis of ferrocenyl cycloheptadienones
Açıkgöz, Canet; Zora, Metin; Department of Chemistry (2005)
Synthesis of seven-membered ring systems such as cycloheptadienones has attracted a great deal of attention in organic chemistry since they are present in a variety of biologically important molecules. Incorporation of the essential structures of such compounds with a ferrocene moiety instead of an aryl group could provide subtances with enhanced antitumor activities since some ferrocene derivatives have already proved to be active against a number of tumors. To develop a ferrocenyl-substituted seven-member...
Addition of trifluoromethyltrimethylsilane to acyl phosphonates: Synthesis of TMS-Protected 1-alkyl-1-trifluoromethyl-1-hydroxyphosphonates and 1-aryldifluoroethenyl phosphates
Demir, Ayhan Sıtkı; Eymur, Serkan (American Chemical Society (ACS), 2007-10-26)
Addition reactions of nucleophilic CF3TMS to acyl phosphonates were investigated. Various acyl phosphonates reacted readily with CF3TMS in the presence of K2CO3 in DMF at rt to give 1-alkyl-2,2,2-trifluoro-1-trimethylsilyloxyethylphosphonate in 70−90% yields. When benzoyl phosphonates were used as starting material, after addition of CF3, the formed alcoholate undergoes phosphonate−phosphate rearrangement to form the acyl anion, followed by elimination of F- to give 1-aryldifluoroethenyl phosphates in 87−97...
Transition structures, energetics, and nucleus-independent chemical shifts for 6 pi electrocyclizations of dienylketenes to cyclohexadienones: A DFT study
Zora, Metin (American Chemical Society (ACS), 2004-03-19)
6pi electrocyclizations of dienylketenes to 2,4-cyclohexadienones have been investigated at the (U)B3LYP/6-31G* level and found to be a favored and exothermic process for most dienylketenes. As evidenced by calculations, dienylketene cyclizations proceed via a pseudopericyclic process. If the terminal double bond of dienylketenes is embedded into a benzenoid-type aryl moiety, the partial or complete loss of aromaticity, as indicated by NICS values, increases the activation barrier and makes the reaction les...
Synthesis of heterocyclic amine substituted novel 1,4-Aminoalcohols and applications in various asymmetric transformations
Keskin, Eda; Tanyeli, Cihangir; Department of Chemistry (2007)
Aminoalcohols are very important compounds used in various asymmetric transformations as chiral ligands or chiral auxiliaries. In this thesis, four novel heterocyclic amine substituted chiral 1,4-aminoalcohols were synthesized. In the synthetic strategy, amide esters were synthesized from (2S, 3R)-3-methoxycarbonylbicyclo[2.2.1]hept-5-ene-2-carboxylic acid by DCC coupling method. Subsequent reduction of these amide esters lead to target 1,4-aminoalcohols. The activities of these novel chiral 1,4-aminoalcoho...
Citation Formats
M. Köktürk, “Synthesis of ferrocenylidene cyclopentenediones,” M.S. - Master of Science, Middle East Technical University, 2005.
METU IIS - Integrated Information Service open@metu.edu.tr