Development of novel methodologies utilizing quaternary ammonium salts as catalysts

Cullen, Lindsey R

Permalink

https://hdl.handle.net/2142/88216 Copy

Description

Title

Development of novel methodologies utilizing quaternary ammonium salts as catalysts

Author(s)

Cullen, Lindsey R

Issue Date

2015-07-17

Director of Research (if dissertation) or Advisor (if thesis)

Denmark, Scott E.

Doctoral Committee Chair(s)

Denmark, Scott E.

Committee Member(s)

• Burke, Martin D.
• Zimmerman, Steven C.
• Silverman, Scott K.

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

Phase Transfer Catalysis

Abstract

The first half of this thesis (Chapter 2) described the development of a fluoride-promoted conjugate addition of sulfur-stabilized carbanion nucleophiles to α,β-unsaturated ketones and esters. This reaction was achieved using a substoichiometric amount of TBAF, resulting in high yields on the desired 1,4-addition product. The addition of 1,3-dithianes was given particular focus as a novel method for the preparation of differentially protect 1,4-dicarbonyl compounds. Observation by 13C NMR spectroscopy provided evidence that the reaction proceeds through an ion pair, and attempts to extend this reaction to asymmetric additions using a chiral counterion are presented in detail. The second half of this thesis (Chapter 3) details development of a phase transfer catalyzed [2,3]-sigmatropic rearrangement of allyloxy carbonyl compounds. Initial investigation focused on identifying viable substrate classes that would undergo selective [2,3]-rearrangement under phase transfer conditions. Under certain conditions, the [2,3]-sigmatropic rearrangement of allyloxy carbonyl compounds takes place in the presence of a phase transfer agent, providing a rare example of a phase transfer catalyzed unimolecular reaction. In the course of this investigation it was found that catalysis is dependent on several variables including base concentration, catalyst structure, and substrate lipophilicity. Preliminary testing of chiral, non-racemic phase transfer catalysts has shown promising levels of enantioselectivity for future development.

Graduation Semester

2015-8

Type of Resource

text

Permalink

http://hdl.handle.net/2142/88216

Copyright and License Information

Copyright Lindsey Cullen 2015

Owning Collections