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  • 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

Asymmetric Alkenylation of Enones and Other α,β-Unsaturated Carbonyl Derivatives Using Chiral 3,3′-Disubstituted Binaphthols and Boronates

Guobadia, Bobby 22 May 2009 (has links)
Various α,β-unsaturated carbonyl compounds and derivatives were explored in order to expand the range of substrates for the 1,4-addition of alkenylboronates using 3,3′-disubstituted binaphthols. Enones 2.60 were examined and found to be suitable for conjugate addition under our proposed reaction conditions. The asymmetric 1,4-additions of alkenylboronates to enones 2.60 using catalytic amounts of 3,3′-disubstituted binaphthols was shown to occur with moderate to good yields and high enantioselectivities. The chiral products could serve as enantioenriched substrates for further transformation such as asymmetric reduction, which was performed with good yield and selectivity. The absolute configuration for the alkenylation of enones was also confirmed to be the (R) enantiomer using (S)-3,3′-disubstituted binaphthols via X-ray crystallographic analysis. Investigations into selective Baeyer-Villiger oxidation of 1,4-addition products of enones was also examined. Although the desire ester products were not obtained, intriguing informative findings were still obtained from the investigation.
2

Asymmetric Alkenylation of Enones and Other α,β-Unsaturated Carbonyl Derivatives Using Chiral 3,3′-Disubstituted Binaphthols and Boronates

Guobadia, Bobby 22 May 2009 (has links)
Various α,β-unsaturated carbonyl compounds and derivatives were explored in order to expand the range of substrates for the 1,4-addition of alkenylboronates using 3,3′-disubstituted binaphthols. Enones 2.60 were examined and found to be suitable for conjugate addition under our proposed reaction conditions. The asymmetric 1,4-additions of alkenylboronates to enones 2.60 using catalytic amounts of 3,3′-disubstituted binaphthols was shown to occur with moderate to good yields and high enantioselectivities. The chiral products could serve as enantioenriched substrates for further transformation such as asymmetric reduction, which was performed with good yield and selectivity. The absolute configuration for the alkenylation of enones was also confirmed to be the (R) enantiomer using (S)-3,3′-disubstituted binaphthols via X-ray crystallographic analysis. Investigations into selective Baeyer-Villiger oxidation of 1,4-addition products of enones was also examined. Although the desire ester products were not obtained, intriguing informative findings were still obtained from the investigation.

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