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Theses Doctoral

Part I: Development of Aromatic Ions as Organocatalysts Part II: Development of Organocatalytic Carbonyl Olefin Metathesis

Vanos, Christine Marie

This thesis describes the development of novel organocatalysts within two areas of focus; aromatic ions and carbonyl olefin metathesis. The first chapter describes the extension of aromatic ion activation of alcohols to oximes for the Beckmann rearrangement. The enhanced reactivity of this reagent is discussed. The mechanism using this protocol, as well as established methods, is also considered, especially as it relates to catalysis versus initiation.
The second chapter describes the development of the first cyclopropenone-catalyzed process; chlorodehydration of alcohols. This process, which proceeds via an SN2 mechanism, is shown for a number of benzylic, allylic, propargylic, and aliphatic alcohols, resulting in high yields and complete inversion of stereochemistry, which is an improvement over traditional methods. The catalytic mechanism is also discussed.
The third chapter describes the development of a new carbonyl olefin metathesis paradigm. In contrast with traditional double bond metathesis methods, which rely on a reversible [2+2] cycloaddition, this newly developed method proceeds through a reversible [3+2] cycloaddition. Proceeding via a 1,3-dipolar cycloaddition, this novel reaction is a hydrazine-catalyzed aldehyde-olefin metathesis. The reaction design and optimization is detailed, and the current scope discussed. Control experiments and preliminary mechanism investigation have been completed and are presented.



More About This Work

Academic Units
Thesis Advisors
Lambert, Tristan H.
Ph.D., Columbia University
Published Here
April 15, 2014