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New stereoselective reactions to form amido alkyl c-n and vinyl triflate c-o bonds via carbocation intermediates & ultrafast silicon fluorination methodologies for applications in pet imaging

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Date Issued:
2014
Summary:
We report here the development of a Lewis acid catalyzed method for the dehydrative coupling of cyclic alcohols and nitriles to form amides with retention of configuration. By contrast, the formation of amides by nitrile trapping of carbocations (Ritter reaction) usually affords racemic product. The present reaction was accomplished by first converting alcohol starting materials to their corresponding chlorosulfites in situ. Even after an extensive search, only copper (II) salts were able to produce the desired conversion of these chlorosulfites to amides though with low catalytic turnover. Improving the turnover without deteriorating the stereochemical outcome was eventually accomplished by a careful selection of the reagent addition sequence and through the removal of gaseous byproducts. This Ritter-like coupling reaction proceeds in good yields with secondary cyclic alcohols under mild conditions. The stereochemical outcome likely due to fast nucleophilic capture of a non-planar carbocations (hyperconjomers) stabilized by ring hyperconjugation.
Title: New stereoselective reactions to form amido alkyl c-n and vinyl triflate c-o bonds via carbocation intermediates & ultrafast silicon fluorination methodologies for applications in pet imaging.
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Name(s): Alhuniti, Mohammed, author
Lepore, Salvatore D., Thesis advisor
Florida Atlantic University, Degree grantor
Charles E. Schmidt College of Science
Department of Chemistry and Biochemistry
Type of Resource: text
Genre: Electronic Thesis Or Dissertation
Date Created: 2014
Date Issued: 2014
Publisher: Florida Atlantic University
Place of Publication: Boca Raton, Fla.
Physical Form: application/pdf
Extent: 153 p.
Language(s): English
Summary: We report here the development of a Lewis acid catalyzed method for the dehydrative coupling of cyclic alcohols and nitriles to form amides with retention of configuration. By contrast, the formation of amides by nitrile trapping of carbocations (Ritter reaction) usually affords racemic product. The present reaction was accomplished by first converting alcohol starting materials to their corresponding chlorosulfites in situ. Even after an extensive search, only copper (II) salts were able to produce the desired conversion of these chlorosulfites to amides though with low catalytic turnover. Improving the turnover without deteriorating the stereochemical outcome was eventually accomplished by a careful selection of the reagent addition sequence and through the removal of gaseous byproducts. This Ritter-like coupling reaction proceeds in good yields with secondary cyclic alcohols under mild conditions. The stereochemical outcome likely due to fast nucleophilic capture of a non-planar carbocations (hyperconjomers) stabilized by ring hyperconjugation.
Identifier: FA00004262 (IID)
Degree granted: Dissertation (Ph.D.)--Florida Atlantic University, 2014.
Collection: FAU Electronic Theses and Dissertations Collection
Note(s): Includes bibliography.
Subject(s): Intermediates (Chemistry)
Nuclear medicine
Organometallic chemistry
Physical organic chemistry
Reaction mechanisms (Chemistry)
Tomography, Emission
Held by: Florida Atlantic University Libraries
Sublocation: Digital Library
Persistent Link to This Record: http://purl.flvc.org/fau/fd/FA00004262
Use and Reproduction: Copyright © is held by the author, with permission granted to Florida Atlantic University to digitize, archive and distribute this item for non-profit research and educational purposes. Any reuse of this item in excess of fair use or other copyright exemptions requires permission of the copyright holder.
Use and Reproduction: http://rightsstatements.org/vocab/InC/1.0/
Host Institution: FAU
Is Part of Series: Florida Atlantic University Digital Library Collections.