A fundamental problem in many-body physics is the behaviour of collective degrees of freedom (DOF) in finite temperatures. The ubiquitous quasiparticle paradigm – phonons for vibrational DOF and magnons for magnetic DOF - linearizes the theory to arrive at an independent particle description. That this picture fails in finite temperatures is well-known and is usually addressed through a perturbative approach, supplementing the ideal plane waves with magnon-magnon and phonon-phonon scattering. Similarly, spin-lattice coupling can also compromise the validity of the phonon and magnon pictures. Spin-lattice interaction has recently attracted increased experimental and theoretical attention, given its potential significance in many subfields of material science, such as spin-thermoelectrics and spintronics. Still, most treatments remain perturbative, offering only renormalized resonances and finite excitation lifetimes. The inadequacy of such a description is immediately apparent for paramagnetism, or structural phase transitions, where the original ordered ground state of the quasiparticle is gone. This study sets out to establish a new conceptual framework for measuring and evaluating magnon-phonon interactions in crystals, adopting a phenomenological self-energy description which makes no assumptions about the magnitude of the effect. We will model the effect using many-body Green's functions to parameterize the excitation's correlation function and map the interaction into the diffuse X-ray pattern of archetypical systems (Fe, MnO, Co). Next, we will apply the generalized scheme to measure magnetic excitations in metal-organic frameworks inaccessible by traditional probes. Finally, I will explore the existence of paramagnons and magnetic phase transition above the Néel temperature. All three avenues, realized under a shared scheme, offer insight into a new unified phenomenological theory for vibrational-magnetic excitations in finite temperatures.

Suzuki−Miyaura coupling (SMC) has emerged as a powerful strategy in the field of cross-coupling reactions and is widely used in synthetic organic chemistry and drug development. Asymmetric SMC reactions employing aryl/alkenyl boronic acid is well developed; however, no general Csp3 – Csp3 Suzuki-Miyaura coupling is currently available. Furthermore, the asymmetric addition of benzylic nucleophile or 1,1-difunctionalized reagents as a nucleophile is quite rare. This proposal aims to develop a general cross-coupling procedure that will effectively allow the use of 1,1-bisboryl alkanes in asymmetric SMC reactions. We intend to utilise the rhodium and copper catalysed dynamic kinetic asymmetric transformations (DYKAT) protocol developed in the Fletcher group to achieve this transformation. The corresponding enantioenriched product would feature boronic ester moiety equipped for further modification. Furthermore, the transformation would serve as an alternative protocol for the addition of difficult to install benzylic group. The method would provide a significant advancement in asymmetric cross-coupling reactions and would fortify the broad applicability of DYKATs in SMC reactions in the field of synthesis, medicinal and materials chemistry.

The importance of natural products and derivatives as sources of new drugs is undeniable. Newman has stated: "It is probably true that if one had to name the natural product that has saved the most lives.....penicillin G would be the molecule of choice" (D. J. Newman, G. M. Cragg, in Natural Product Chemistry for Drug Discovery, Chapter 1, RSC Biolmolecular Sciences No. 18, 2009). In this proposal we will develop methodology for the synthesis of two types of closely related natural products which have wide-ranging biological activities including: anti-bacterial, anti-viral, anti-tumour and herbicidal activity; but whose biological activities have not been fully evaluated. We will use our recently developed oxidative radical cyclisation methodology to synthesise the cores of these biologically relevant natural products and develop new methodology for the direct functionalisation of certain aromatic heterocycles as part of the synthesis of the unsaturated portions of the natural products. The biological activities, particularly with respect to anti-bacterial and anti-tumour properties of all of the key synthetic intermediates (simplified analogues) and synthetic natural products themselves will be assessed. The project is divided into four work packages involving: i) development of direct functionalisation certain aromatic heterocycles; ii) synthesis of the the one type of natural product; iii) oxidative radical synthesis of natural product cores; iv) total synthesis of the second type of natural product.