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Methodenentwicklung zur selektiven Herstellung achiraler 1,3–substituierter Ferrocene und Untersuchung des Halogentanzes am Ferrocen
Alexander Herlein
Art der Arbeit
Masterarbeit
Universität
Universität Wien
Fakultät
Fakultät für Chemie
Betreuer*in
Walter Weissensteiner
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DOI
10.25365/thesis.30566
URN
urn:nbn:at:at-ubw:1-30315.23646.117754-6
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Abstracts

Abstract
(Englisch)
This thesis describes the synthesis of 1,3–substituted ferrocenes and investigations of a possible halogen dance mechanism on halideferrocenes. A molecule of interest was 1,3–diiodoferrocene which could easily be modified through other electrophiles. This was achieved through consecutive deprotonation of bromoferrocene, subsequent reaction with an electrophile and selective removal of the bromine substituent. Through lithiation of bromoferrocene and subsequent reaction with an electrophile rac–2–bromoiodoferrocene was isolated in good yields as well as other racemic 2–substituted bromoferrocenes. A preparation of rac–2–bromoiodoferrocene was also possible through substitution of a tributyltin substituent with iodine. A direct synthesis of 2–bromo–1,3–diiodoferrocen by lithiation of rac–2–bromoiodoferrocene and subsequent introduction of an iodine substituent (R2) was not possible because of an appearance of a halogen dance. This problem could be solved by preparation of 1,3–bis(tributyltin)–2–bromoferrcene and subsequent substitution of both tributyltin substituents with iodine. Based on 1,3–bis(tributyltin)–2–bromoferrcene it was possible to receive 1,3–diiodoferrocene through a selective removal of the bromine with tBuLi and subsequent substitution of the tributyltin groups with iodine. Mechanism investigations of the halogen dance were carried out based on rac–2–bromoiodoferrocene and 2–bromo–1,3–diiodoferrocen. It was possible to identify and characterize lithiated intermediates of the halogen dance through lithiation and subsequent reaction with a proton– or deuterium source of these substances. It was found that the product distribution is dependent on temperature, reactivity of the electrophile and the addition rate of the lithiated species to the electrophile. Further was shown that lithiation prefer to appear adjacent to an electronegative substituent to give a better stabilized anion.

Schlagwörter

Schlagwörter
(Englisch)
ortho-metallation halogen dance achiral ferrocenes
Schlagwörter
(Deutsch)
ortho–Metallierung Halogentanz achirale Ferrocene
Autor*innen
Alexander Herlein
Haupttitel (Deutsch)
Methodenentwicklung zur selektiven Herstellung achiraler 1,3–substituierter Ferrocene und Untersuchung des Halogentanzes am Ferrocen
Publikationsjahr
2013
Umfangsangabe
74 S. : Ill., graph. Darst.
Sprache
Deutsch
Beurteiler*in
Walter Weissensteiner
Klassifikationen
35 Chemie > 35.52 Präparative Organische Chemie ,
35 Chemie > 35.60 Metallorganische Verbindungen
AC Nummer
AC11818948
Utheses ID
27237
Studienkennzahl
UA | 066 | 862 | |
Universität Wien, Universitätsbibliothek, 1010 Wien, Universitätsring 1