Novel Applications of Donor-Acceptor Cyclopropanes and Dearomatization towards the Expedient Synthesis of Highly Substituted Carbocycles Public Deposited

Downloadable Content

Download PDF
Last Modified
  • March 22, 2019
Creator
  • Mackay, William
    • Affiliation: College of Arts and Sciences, Department of Chemistry
Abstract
  • I. Lewis Acid Catalyzed (3+2)-Annulations of Donor-Acceptor Cyclopropanes and Ynamides. The Sc(OTf)3-catalyzed (3+2)-annulation of donor-acceptor cyclopropanes and ynamides is described, providing the corresponding cyclopentene sulfonamides in good to excellent yield. Deprotection and hydrolysis of the resulting cyclopentenesulfonamides delivers 2,3-substituted cyclopentanones with high diastereoselectivity. II. Kinetic Separation and Asymmetric Reactions of Norcaradiene Cycloadducts: Facilitated Access via H2O-Accelerated Cycloaddition. We exploit the Buchner reaction to access 1,2-disubstituted cyclohexadiene synthons (norcaradienes), which participate in H2O-accelerated cycloaddition with dienophiles to provide cyclopropyl-fused [2.2.2]-bicyclooctene derivatives in good yields. Regioisomeric mixtures can be kinetically separated exploiting different reaction rates in Diels-Alder reactions. meso-Diels-Alder products may be enantioselectively desymmetrized, providing highly substituted cyclohexanes with up to seven contiguous stereocenters. III. The Development of Regioisomerically Enriched Buchner Products for Use as Cyclohexadienyl Synthetic Intermediates. We have investigated two conceptual methods to generate highly regioisomerically enriched norcaradienyl intermediates through arene cyclopropanation. Intermolecular Buchner reaction of aryl diazoacetates under either thermolysis or silver(I) catalysis provide expedient routes to single regioisomeric norcaradienes, in some cases favoring the least sterically encumbered site of cyclopropanation. Intramolecular Buchner reaction of benzyl cyanodiazoacetates allow for the site-selective cyclopropanation of the tethered arene, and the installation of an activated cyclopropane for downstream functionalization. Both methods generate norcaradienes that are amenable to further transformations to generate highly stereochemically complex carbocyclic products.
Date of publication
Keyword
DOI
Resource type
Rights statement
  • In Copyright
Advisor
  • Brustad, Eric
  • Johnson, Jeffrey
  • Gagne, Michel
  • Waters, Marcey
  • Miller, Alexander
Degree
  • Doctor of Philosophy
Degree granting institution
  • University of North Carolina at Chapel Hill
Graduation year
  • 2017
Language
Parents:

This work has no parents.

Items