Part I: Synthesis and chemistry of 2-aryl-2-nitroacetates. Part II: Development of anion-binding catalysts. Part III: Analysis of an axial chiral tetrachlorinated bisbenzo[a]phenazine / Metz, Alison E.

Format:

Book

Thesis/Dissertation

Author/Creator:

Metz, Alison E., author.

Contributor:

Kozlowski, Marisa C., 1967- degree supervisor.

Walsh, Patrick J., degree committee member.

Smith, Amos B., degree committee member.

Percec, Virgil, degree committee member.

University of Pennsylvania. Chemistry, degree granting institution.

Language:

English

Subjects (All):

Organic chemistry.

0490.

Local Subjects:

Organic chemistry.

0490.

Genre:

Academic theses.

Physical Description:

1 electronic resource (383 pages)

Contained In:

Dissertation Abstracts International 77-01B(E).

Place of Publication:

Ann Arbor : ProQuest Dissertations & Theses, 2015.

Language Note:

English

Summary:

PART I. There are few reports on the synthesis of 2-aryl-2-nitroacetates, highlighting a need for development in this area. This section describes a high-throughput experimentation (HTE) approach to discover suitable conditions for the coupling of aryl bromides and alpha-nitroacetates to generate 2-aryl-2-nitroacetates. The best reaction conditions are 2.5 mol % Pd2dba3•CHCl 3, 10 mol % t-BuXPhos, 1.2 equiv CsHCO3 in toluene at 75 °C, which afford products in isolated yields of 52--96%.

2-Aryl-2-nitroacetates are central precursors to other small molecules making them valuable building blocks in synthesis. Efficient methods were developed for the conversion of 2-aryl-2-nitroacetates to several product classes that are difficult to make: aryl nitromethanes (76--98% yield), alpha-keto esters (51--86% yield), and alpha-aryl alpha-amino acids (63--85% yield).

PART II. Small molecule organocatalytic anion-binding chemistry is in its early stages of development in the organic laboratory, and research in this field is important for its advancement. This section describes synthesis of a new class of anion-binding catalysts focused on a xanthene scaffold.

Over twenty potential catalysts were made and include three types: unsymmetrical catalysts, C2-symmetrical catalysts, and bifunctional catalysts. These compounds are better at promoting the Pictet-Spengler-type reaction previously reported by Jacobsen. Because of this fact the cyclization of 3- and 2-substituted furans into N-acyliminium ions was investigated. The top catalyst for 2-substituted furans is a bisamide xanthene compound (60% conversion), and the top catalyst for 3-substituted furans is a thiourea-amide xanthene compound (42% conversion, 24% ee).

PART III. The discovery of new materials is an exciting and important field of organic synthesis. A tetrachlorinated bisbenzo[ a]phenazine was accessed in seven steps and 14% overall yield (99% ee). It has unique chromic properties that justify its application in functional materials. The color-changing transitions and the corresponding solid phases were studied using single crystal x-ray diffraction, powder x-ray diffraction, photo-image processing, and differential scanning calorimetry. These properties arise from two polymorphs and the ability of the phenazine to form weak OH•••Cl interactions.

Notes:

Source: Dissertation Abstracts International, Volume: 77-01(E), Section: B.

Advisors: Marisa C. Kozlowski Committee members: Virgil Percec; Amos B. Smith; Patrick J. Walsh.

Ph.D. University of Pennsylvania 2015.

Local Notes:

School code: 0175

ISBN:

9781339027555