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1993 (1)
1Author    Herwig Schottenberger, Michael Buchmeiser, Johann Polin, K. Arl-, Eberhard SchwarzhansRequires cookie*
 Title    Ferrocen-Derivate der Quadrat-und Propiolsäure. Synthesen und Reaktionen Ferrocene Derivatives of Squaric Acid and Propiolic Acid. Syntheses and Reactions  
 Abstract    Concepts for linking ferrocene derivatives with conjugated squarate and propiolate based spacer systems have been investigated. Coupling o f 3,4-dichlorocyclobut-3-ene-l,2-dione (squaric acid dichloride) with cuproferrocene • dim ethylsulfide resulted in 3-chloro-4-ferrocenylcyclobut-3-ene-l,2-dione (ferrocenylsemisquaric acid chloride) and 3,4-diferro-cenylcyclobut-3-ene-l,2-dione. Ferrocenylsemisquaric acid chloride was further treated with ethynylferrocene and 4-ethynyl-4-(ferrocenylethynyl)tolan, respectively, to form the corre­ sponding mixed squaric diketones, which required Zn/Pd mediated coupling conditions for sufficient conversion. The symmetrically substituted derivative o f ferrocenylacetylene was pre­ pared by the same method. Cupration and subsequent coupling o f dilithioferrocene with one equivalent o f iodopro-piolic acid methyl ester yielded l'-iodo-l-ferrocenylpropiolic acid methyl ester, and with two equivalents l,16-bis(m ethoxycarbonylethynyl)biferrocene. N ucleophilic addition o f secondary amines to ferrocenylpropiolic acid ethyl ester gave aminoacrylates as intermediates, which rap­ idly converted to ketoesters during workup. Only in the case o f morpholine the corresponding adduct (ferrocenylmorpholino acrylate) could be isolated. l,3-Diferrocenylprop-2-ene-J-one has been obtained in a Benary reaction o f lithioferrocene with 3-diethylam inoethyl acrylate in quantitative yield. In order to provide alternative syntheses o f already known com pounds the substitution be­ havior o f different metallated ferrocene intermediates has also been evaluated by reaction with other acid halides (oxalyl chloride, thiophosgene, ethyl chloroformate). All new com pounds, 3-chloro-4-ferrocenylcyclobut-3-ene-l,2-dione (1); 
  Reference    Z. Naturforsch. 48b, 1524—1532 (1993); eingegangen am 8. Juli 1993 
  Published    1993 
  Keywords    Ferrocenes, Alkynes, Squaric Acid Derivatives, Propiolic and Acrylic Esters 
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 TEI-XML for    default:Reihe_B/48/ZNB-1993-48b-1524.pdf 
 Identifier    ZNB-1993-48b-1524 
 Volume    48