Novel Transition Metal or Phosphine-Mediated Bond Activations for C-C/C-X Bond Formations

Doctoral Dissertation


For decades, cycloaddition reactions have been a staple in the organic chemist’s toolbox, providing access to a variety of biologically interesting heterocyclic compounds. In particular, [4+n]-cycloadditions have been utilized extensively to access, five, six, and seven-membered rings with a range of substitution patterns. Our interest lied in the [4+1]-construction of potentially bioactive five-membered heterocycles, which are commonly constructed via a [3+2]-cycloaddition reaction between a 1,3-dipole and a dipolarophile. While this is an elegant approach, it is limited by the high level of reactivity of the starting materials.

With this is mind, we anticipated that the [4+1] retrosynthetic disconnect would be an efficiacious approach providing ready access to the desired heterocycles without the chemoselectivity and regioselectivity challenges that can arise with [3+2] cycloadditions. Additionally, the variety of four atom components available would allow access to multiple heterocyclic motifs. Towards that end, we successfully employed aza ortho-quinone methides, aroyl isocyanates, vinyl ketenes, and vinyl allenes as four atom components in conjunction with metal-stabilized carbenes or phosphorus-based carbenoids as C1-synthons to generate dihydroindoles, oxazolones, and spirooxindole cyclopentenones.


Attribute NameValues
Author Kaitlyn E. Eckert
Contributor Brandon L. Ashfeld, Research Director
Degree Level Doctoral Dissertation
Degree Discipline Chemistry and Biochemistry
Degree Name Doctor of Philosophy
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Defense Date
  • 2019-03-26

Submission Date 2019-04-08
Record Visibility Public
Content License
  • All rights reserved

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