Copper-activated dioxygen species have been well known as key intermediates in the metalloenzymes and industrial catalysts. In synthetic chemistry, reactivity study of copper-reactive oxygen adducts was investigated to understand the enzymatic processes. However, the examination of reactivity is still limited to certain intermediates such as copper-superoxo species. The diverse type of reactivity of copper-reactive oxygen species needs to be studied extensively. Especially, the copper(II)-hydroperoxo and -alkylperoxo complexes have conducted only electrophilic reactivity through the O-O bond cleavage, so far. In this dissertation, the nucleophilic reactivity of copper(II)-activated dioxygen intermediates has been focused. In chapter 1, the nucleophilic reactivity of a copper(II)-hydroperoxo complex has been observed. The copper(II)-hydroperoxo species shows highly oxidative reactivity in aldehyde deformylation. In chapter 2, the temperature dependence of the reactivity of copper(II)-alkylperoxo complexes in aldehyde deformylation and catalytic C-H bond activation has been investigated. In chapter 3, the ligand-based alkylperoxide binding copper complex was studied. Interestingly, depending on the Lewis acidity of redox-inactive metal ions, the nucleophilic reactivity of a copper(II)-ligand-based alkylperoxo complex was enhanced and modulated. All of the copper(II)-reactive dioxygen species have been characterized with various physicochemical methods such as ultraviolet-visible (UV-vis) spectroscopy, cold-spray ionization mass spectrometry (CSI-MS), resonance Raman (rRaman) spectroscopy and electron paramagnetic resonance (EPR) spectroscopy. The nucleophilic character of copper(II)-hydroperoxo and -alkylperoxo complexes was determined by the positive Hammett ρ values.
Table Of Contents
Abstract i General Introduction 1 Chapter 1. Nucleophilic reactivity of copper(II)-hydroperoxo complex 17 1.1. Abstract 17 1.2. Introduction 19 1.3. Results and Discussion 21 1.4. Conclusion 44 1.5. Experimental Section 45 1.6. References 51 Chapter 2. Nucleophilic reactivity of a copper(II)-alkylperoxo complexes 56 2.1. Abstract 56 2.2. Introduction 57 2.3. Results and Discussion 59 2.4. Conclusion 83 2.5. Experimental Section 84 2.6. References 90 Chapter 3. Redox-inactive metal ions enhance the nucleophilic reactivity of an alkylperoxocopper(II) complex 94 3.1. Abstract 94 3.2. Introduction 96 3.3. Results and Discussion 99 3.4. Conclusion 119 3.5. Experimental Section 120 3.6. References 123 Concluding Remarks 126 Acknowledgement 128