Modular Synthesis of Asymmetric Triazacyclononane Derivatives and Potential Aerobic Copper Oxidation Catalyst Supported by a Bridging Bulky Triazacyclononane Público

Abstract

Metalloenzymes carry out synthetically challenging oxidations, usually involving an earth abundant bimetallic center and atmospheric oxygen. 1,4,7-triazacyclononane (tacn) derivatives have historically been used to model the active sites in these enzymes. However, above cryogenic temperatures, these model systems oxidize the ligand, preventing catalysis at ambient temperatures. Until recently, there had been no precedent for creating bulky substituents on tacn to prevent ligand degradation. This report will describe the scope of the ^tBu3tacn synthesis to other tacn derivatives, in particular, to binucleating tacn derivatives with tert-butyl substituents, and the corresponding coordination chemistry. Furthermore, studies on intramolecular oxidation of these bimetallic complexes will be described. Finally, preliminary results will demonstrate progress to prevent ligand degradation.

Table of Contents

1.0 Introduction: An Oxidation Problem. 1

1.1 Oxidations in Biology

1.2 Copper and Dioxygen in Synthetic Systems

1.2.1 Binucleating Systems

1.2.2 Ligand Degradation

1.3 Previous Derivatives of tacn

1.4 Goals of the Project

2.0 Results and Discussion. 11

2.1 Alternative Synthesis to Known tacn Derivatives

2.2 Di- and Mono- tert-butyl tacn

2.3 Bridging tacn Synthesis

2.4 Bridging Copper tacn Complexes

3.0 Future Studies. 22

3.1 Spectroscopic Studies

3.2 New Bridging Ligands

3.2.1 Aryl-Bridging Unit

3.2.2 Methyl-Protected Bridging Unit

4.0 Conclusions. 25

5.0 Experimental. 26

5.1 General Considerations

5.2 Ligand Syntheses

5.2.1 Chloro-acetylation

5.2.2 Cyclizations

5.2.3 Oxidation/Reductions

5.3 Metal Complexes

6.0 Supporting Information. 34

7.0 References. 44

About this Master's Thesis

Rights statement

• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Laney Graduate School
Department	Chemistry
Degree	MS
Submission	Master's Thesis
Language	English
Research Field	Chemistry, Organic Chemistry, Inorganic
Palabra Clave	binucleating triazacyclononane copper complex aerobic oxidation tert-butyl
Committee Chair / Thesis Advisor	Scarborough, Christopher C, Emory University
Committee Members	Hill, Craig L, Emory University MacBeth, Cora E., Emory University

Última modificación

Primary PDF

Thumbnail	Title	Date Uploaded	Actions
	Modular Synthesis of Asymmetric Triazacyclononane Derivatives and Potential Aerobic Copper Oxidation Catalyst Supported by a Bridging Bulky Triazacyclononane ()	2018-08-28 11:45:11 -0400	Press to Select an action Download

Supplemental Files

Thumbnail	Title	Date Uploaded	Actions