Current Search: He, Chang. (x)
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Title
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Studies towards a catalytic asymmetric isomerization of manganese complexed alkynes to allenes using chiral bases.
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Creator
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He, Chang., Charles E. Schmidt College of Science, Department of Chemistry and Biochemistry
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Abstract/Description
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The conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement...
Show moreThe conversion of alkynyl carbonyls to allenyl carbonyls via manganese mediated coordination followed by a base-catalyzed isomerization was carried out using a range of chiral and achiral amine bases. Chiral amidine and chiral DBU derivatives were synthesized to carry out the isomerization enantioselectively. We employed HPLC equipped with a chiral column to determine the enantiomeric excess. We also proved that the mechanism of that the manganese-coordinated alkyne/allene rearrangement reaction involved an intermediate cumenolate. It was also confirmed that amine base with pKa lower than that of DBU (pKa = 13.6) would not carry out the isomerization. Alkoxy base were also used in isomerization and the mechanism was also investigated.
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Date Issued
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2009
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PURL
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http://purl.flvc.org/FAU/192983
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Subject Headings
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Enzyme kinetics, Organometallic compounds, Synthesis, Asymmetric synthesis, Methathesis (Chemistry), Carbonyl compounds, Synthesis
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Format
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Document (PDF)