Catalytic studies on copper(I) complexes under technical conditions
File(s)
Author(s)
Pimpasri, Chaleena
Type
Thesis
Abstract
Transition metal catalysis plays an important role in organic synthesis, and it can provide an atom economical and efficient manner processes. Copper catalysts are one of the competitive choices among transition metals due to their low toxicity and low-price metals. This thesis details the development of novel copper complexes bearing different types of ligands. Their catalytic activities are investigated in the reduction of azides to amines and in intramolecular hydroalkoxylation and hydrocarboxylation reactions.
The first chapter presents an overview of pyrazole-based, pyridine bis-imine/amine (PDI) and (PDA) ligands, N-heterocyclic iminocarbene and ring-expanded N-heterocyclic carbene utilised in transition metal and catalytic chemistry. In addition, the synthesis of those pincers and their copper complexes are provided. A discussion on spectroscopic characterisation and X-ray structures is also provided, including the behaviour of neutral [Cu(PDI)] investigated by Evans NMR and EPR.
Chapter 2 shows a brief introduction to amines and their utilisation. The preparation of primary amines from azides and the application of copper(I) complexes to azide reduction are also reviewed. The successful results of [Cu(PDIDMA)2]BF4 in a mixture of DMSO and water applied to the reduction of azides to amines are discussed. The moderate to excellent yields of electron-poor aryl amines are observed without an additional H source. The investigation of hydrogen peroxide formation and the proposed mechanism are also discussed.
Following this, the third chapter outlines an overview of applications of transition and rare earth metals in intramolecular hydroalkoxylation and hydrocarboxylation reactions. The screening processes are discussed using different copper(I) complexes, solvents, and temperatures to find the optimal conditions. Discussion on the preparation of starting materials and their corresponding products is provided. Moreover, a possible mechanism is also suggested.
Finally, the corresponding experimental section, X-ray crystallography, and additional data are provided at the end of each chapter. The final chapter presents the general conclusion and future work.
The first chapter presents an overview of pyrazole-based, pyridine bis-imine/amine (PDI) and (PDA) ligands, N-heterocyclic iminocarbene and ring-expanded N-heterocyclic carbene utilised in transition metal and catalytic chemistry. In addition, the synthesis of those pincers and their copper complexes are provided. A discussion on spectroscopic characterisation and X-ray structures is also provided, including the behaviour of neutral [Cu(PDI)] investigated by Evans NMR and EPR.
Chapter 2 shows a brief introduction to amines and their utilisation. The preparation of primary amines from azides and the application of copper(I) complexes to azide reduction are also reviewed. The successful results of [Cu(PDIDMA)2]BF4 in a mixture of DMSO and water applied to the reduction of azides to amines are discussed. The moderate to excellent yields of electron-poor aryl amines are observed without an additional H source. The investigation of hydrogen peroxide formation and the proposed mechanism are also discussed.
Following this, the third chapter outlines an overview of applications of transition and rare earth metals in intramolecular hydroalkoxylation and hydrocarboxylation reactions. The screening processes are discussed using different copper(I) complexes, solvents, and temperatures to find the optimal conditions. Discussion on the preparation of starting materials and their corresponding products is provided. Moreover, a possible mechanism is also suggested.
Finally, the corresponding experimental section, X-ray crystallography, and additional data are provided at the end of each chapter. The final chapter presents the general conclusion and future work.
Version
Open Access
Date Issued
2023-04-12
Date Awarded
01/08/2023
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
Díez-González, Silvia
Sponsor
Royal Thai Government Scholarships
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)