Photoredox Catalysts Based on Earth-abundant Metal Complexes

We would like to thank the Engineering and Physical Sciences Research Council and CRITICAT Centre for Doctoral Training for financial support [Ph.D. studentship to B.H.; Grant code: EP/L016419/1]. C.L thanks the Prof. & Mrs Purdie Bequests Scholarship and AstraZeneca for his PhD Studentship.Over the last decade, visible light photoredox catalysis has exploded into the consciousness of the synthetic chemist. The principal photocatalysts used are based on rare and toxic ruthenium(II) and iridium(III) complexes. This critical review focusses on Earth-abundant metal complexes as potential replacement photocatalysts and summarizes the use of photoactive Cu(I), Zn(II), Ni(0), V(V), Zr(IV), W(0), W(VI), Mo(0), Cr(III) , Co(III) and Fe(II) complexes in photoredox reactions. The optoelectronic properties of these complexes and relevant structurally related analogs, not yet used for photoredox catalysis, are disccussed in combination with the reaction scope reported for each photocatalyst. Prospects for the future of photocatalyst design are considered.PostprintPeer reviewe

Recent advances in organic synthesis using light-mediated n-heterocyclic carbene catalysis

The combination of photocatalysis with other ground state catalytic systems have attracted much attention recently due to the enormous synthetic potential offered by a dual activation mode. The use of N-heterocyclic carbene (NHC) as organocatalysts emerged as an important synthetic tool. Its ability to harness umpolung reactivity by the formation of the Breslow intermediate has been employed in the synthesis of thousands of biologically important compounds. However, the available coupling partners are relatively restricted, and its combination with other catalytic systems might improve its synthetic versatility. Thus, merging photoredox and N-heterocyclic carbene (NHC) catalysis has emerged recently as a powerful strategy to develop new transformations and give access to a whole new branch of synthetic possibilities. This review compiles the NHC catalyzed methods mediated by light, either in the presence or absence of an external photocatalyst, that have been described so far, and aims to give an accurate overview of the potential of this activation modeL.M. acknowledges the Autonomous Community of Madrid (CAM) for the financial support (PEJD-2019-PRE/AMB-16640 and SI1/PJI/ 2019-00237) and for an “Atracción de Talento Investigador” contract (2017-T2/AMB-5037

Polyfluoroarylation of oxazolones: access to non-natural fluorinated amino acids

Herein, we demonstrate the use of the oxazolone enolate to access non-natural fluorinated amino acid derivatives.</p

Hope as a predictor of physical activity behavior in middle-aged and older adults with musculoskeletal pain

Background: Musculoskeletal pain is a barrier to physical activity, enhancing functional decline in older adults. Thus, identifying psychological factors that promote physical activity in older adults with musculoskeletal pain is warranted. Prior research shows that the psychological construct of hope predicts the frequency of exercise in healthy younger adults. However, the impact of hope on physical activity behavior in an older population with clinical pain is unknown. This observational study was designed to determine whether hope predicted self-reported and objective physical activity levels in older adults with musculoskeletal pain. Methods: Fifty-two middle-aged to older adults (age range 55-85 years; 67% female) completed all assessments. Participants completed questionnaires to assess hope (Adult Hope Scale), self-reported physical activity (Physical Activity Scale for the Elderly), bodily pain (SF-36), kinesiophobia (Tampa Scale of Kinesiophobia), and pain catastrophizing (Pain Catastrophizing Scale). Participants also wore accelerometers on the hip for one week to objectively measure physical activity levels. Correlations were conducted to determine relationships between variables. Hierarchical regressions were conducted to determine whether hope predicted self-reported and objective physical activity levels after controlling for relevant demographics, pain, and other psychological variables. Results: After controlling for bodily pain, hope significantly predicted self-reported physical activity and was associated with greater physical activity levels. Bodily pain, but not hope, significantly predicted average daily steps derived from the accelerometer. Decreased bodily pain was associated with more daily steps. Conclusion: These findings suggest that trait hope could be a key psychological predictor of self-reported physical activity in older adults with musculoskeletal pain. Clarifying the role of hope in the physical activity behavior of older adults could present a novel target for intervention