Novos aspectos e aplicações da química de teluranas e de teluretos orgânicos / New aspects and applications of the chemistry of organotelluranes and organic tellurides

AUTOR(ES)

Rodrigo Luiz Oliveira Rodrigues Cunha

DATA DE PUBLICAÇÃO

2005

RESUMO

The first part of this thesis deals with the study of the reactivity of electrophilic tellurium compounds, mainly tellurium tetrachloride and aromatic tellurium trichlorides. New aspects of the reactivity of TeCl4 towards alkynes and some acetophenones were disclosed. A mechanistic rationale for each of the processes studied was possible by the determination of the stereochemistry for each product by monocrystal X-ray diffraction analysis. The proposition of the formation of cationic intermediates in the addition reaction of TeCl4 to alkynes was corroborated by the detection and characterization of transient intermediates by ESI-MS/MS experiments. Besides the new aspects of the Tellurium chemistry found, the prepared compounds showed a high and selective activity as inhibitors of cysteine proteases. A pair of enantiomers of a tellurane showed different activities against Human Catepsin B due to a stereochemical dependence in the enzyme/inhibitor interaction. The second part of the present work deals with the development of the ring opening reaction of aziridines by organometallic reagents of copper prepared from vinylic and arylic tellurides. These reactions led to homoallylic and homobenzylic amine derivatives. Finally, the reactivity of 2-alkenyl aziridines was studied towards a series of organometallic reagents of lithium, magnesium, copper and zinc which biased the regio- and stereoselectivities of the ring opening reactions.

ASSUNTO(S)

proteases tellurium enzymatic kinetics tellurium tetrachloride telúrio aziridinas organocuprates cupratos eletrophilic addition reaction teluretos vinílicos catepsina b organometallic compounds cathepsin b heterocycles vinylic tellurides substituição eletrofílica aromática reação de adição eletrofílica tetracloreto de telúrio electrophilic aromatic substitution heterociclos aziridines inibidores enzimáticos proteases cnética enzimática compostos organometálicos enzymatic inhibitors

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