• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • No language data
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Gold(I)-Catalyzed Hydrofunctionilzations of Allenes with Nitrogen and Oxygen Nucleophiles

Duncan, Alethea January 2011 (has links)
<p>The importance of nitrogen-containing compounds in human life has drawn us to focus on the preparation of amine derivatives, combined with the limitations associated with traditional methods for the formation of C-N bonds has prompted us to develop new and efficient syntheses, of amine and ether derivatives and explore the mechanisms of the gold(I)-catalyzed reactions.</p><p>A mixture of AuCl[P(t-Bu)2o-biphenyl] (5 mol %) and AgOTf (5 mol %) served as an effective catalyst for the intermolecular hydroamination of allenes with arylamines to form N-prenylaniline and N,N-diprenylaniline derivatives. This gold(I)-catalyzed protocol was effective for the formation of arylamines at non-forcing conditions with wide substrate scope in both allene and aniline, in high yields with good regioselectivity diastereoselectivity.</p><p>The mechanism of the gold(I)-catalyzed hydroalkoxylation and hydroamination of alcohols and carbamates with allenes, catalyzed by AuIPrCl (IPr= 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidine) and AgOTf was investigated. The experimental rate laws for both reactions indicate first-order behavior in nucleophile and catalyst and zero-order behavior in catalyst. We propose an outer-sphere mechanism with turnover limiting protonolysis for the gold(I)-catalyzed hydrofunctionalization of allenes with alcohols or carbamates based on kinetic isotope effect, saturation behavior, and stereochemical analysis of hydroalkoxylation.</p><p>The mechanism of gold(I)-catalyzed hydroamination of allenes with arylamines was examined. Specifically, we explored the hydroamination of 3-methy-1,2-butadiene with aniline catalyzed by AuCl[P(t-Bu)2o-biphenyl] (5 mol %) and AgOTf (5 mol %) in dioxane at 45 °C to form N-prenylaniline and N,N-diprenylaniline. The kinetics of this reaction were determined to be first-order in aniline, allene, and catalyst. We have concluded that the mechanism for the gold(I)-catalyzed intermolecular hydroamination of allenes with arylamines involves outer-sphere attack of aniline on the gold-&#61552;-allene complex based on stereochemical analysis of the hydroamination product from the reaction of an enantiomerically enriched allene, (R)-1-phenyl-1,2-butadiene, with 3-bromoaniline.</p> / Dissertation

Page generated in 0.0769 seconds