The development and use of novel iridium complexes as catalysts for ortho-directed hydrogen isotope exchange reactions

The preparation and application of groups of new iridium complexes are described. In particular, iridium complexes possessing phosphine ligands and a bulky N-heterocyclic carbene have been shown to be robust and readily handled species and have been applied in a range of directed hydrogen-deuterium and -tritium exchange processes and, in particular, with drug-like substrates or within ADMET-related studies. Overall, these new iridium(I) complexes are shown to be highly active catalysts and display catalytic activity far in excess of the industry standard, Crabtree's catalyst, with excellent levels of labelling being achieved over short reaction times and at low metal complex loadings, whilst tolerating a wide range of functional moieties. Furthermore and again in contrast to systems employing Crabtree's catalyst, the low catalyst loadings and short reaction times made possible by these emerging iridium carbene comple have delivered tritiated products with very good levels of labelling and without any appreciable by-product waste production

Dementia care training for residential care workers: building residential care workers’ own views into a conceptual model

This thesis is the result of research that investigated the views of residential care workers (RCWs) working with people with dementia about their perceptions of training for their dementia care role with older people. Using a constructivist ontology and an interpretivist epistemology, the research investigates how care workers perceive their training and how they feel it can be applied to their working environment. RCWs were asked what they saw as the specific needs of residents with dementia, what training they had received, how useful they perceived the training to be, and what training they felt was still needed. Previous studies had put forward topics for inclusion into dementia care training, but very little research had asked RCWs themselves about their dementia training needs. Nineteen semi-structured interviews were carried out across three care home organisations during the summer of 2013 in the East of England. Findings from thematic analysis showed that the care workers interviewed had very limited or no dementia training or assessment they could remember, and that training had generally been a negative experience. Dementia care trainers were not considered helpful or knowledgeable enough and RCWs identified that their learning needs had not been taken into consideration. The learning environment was viewed as unsuitable, usually a lounge or a bedroom where it was very cramped and RCWs were pulled out of training when there were limited staff numbers. Many challenges specific to caring with people with dementia were also identified: challenging behaviour, lack of time and resources, poor teamwork and communication and lack of organisational support all inhibited the development of person-centred care and training transfer into practice. A conceptual model of the training and learning cycle is proposed as a way forward for dementia training. This model illustrates the training process from course creation through to satisfactory completion. Learning into practice is measured by care workers’ knowledge, confidence, and competence. This assessment is a two-way process between the learner and the mentor to ensure RCWs feel fully supported and recognised. Although this conceptual model has not been tested empirically, such a process is seen as a possible next step

Hydrogen isotope exchange with highly active iridium(I) NHC/phosphine complexes : a comparative counter-ion study

Herein we present a range of substrates that undergo hydrogen isotope exchange with an iridium(I) NHC/phosphine complex bearing the less coordinating tetrakis[3,5-bis(trifluoromethyl)phenyl]borate counterion, and compare these with labelling using the equivalent, more established hexafluorophosphate complex. The changes in reactivity and selectivity of these complexes in a series of solvents are examined

Gibberellin A4 monohydrate

The title compond, C19H24O5·H2O, has two gibberellin A4 mol­ecules and two water mol­ecules in the asymmetric unit. The A and B rings have chair conformations, whereas the C and D rings have envelope conformations; the two rings which contain the lactone and carbonyl bridge adopt chair and envelope conformations. The crystal structure is established by O—H⋯O hydrogen bonds and supported by C—H⋯O hydrogen bonds

Recent advances in iridium(I) catalysis towards directed hydrogen isotope exchange

The initial discovery and establishment of a family of novel iridium catalysts possessing N-heterocyclic carbene units alongside bulky phosphine ligands allowed selected substrates to be labelled using deuterium or tritium gas at desirably low catalyst loadings via an ortho-directed C-H insertion process. Such a method has broad applicability and offers distinct advantages within the pharmaceutical industry, directly facilitating the ability to carefully monitor a potential drug molecule’s biological fate. Over the past decade since these initial protocols were divulged, many additional advances have been made in terms of catalyst design and substrate scope. This review describes the broadened array of new iridium catalysts and associated protocols for direct and selective C-H activation and hydrogen isotope insertion within a number of new chemical entities of direct relevance to the pharmaceutical industry