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Abstract Photoredox nickel catalysis has emerged as a powerful strategy for cross-coupling reactions. Although the involvement of paramagnetic Ni(I)/Ni(III) species as active intermediates in the catalytic cycle has been proposed, a thorough spectroscopic investigation of these species is lacking. Herein, we report the tridentate pyridinophane ligandsRN3 that allow for detailed mechanistic studies of the photocatalytic C–O coupling reaction. The derived (RN3)Ni complexes are active catalysts under mild conditions and without an additional photocatalyst. We also provide direct evidence for the key steps involving paramagnetic Ni species in the proposed catalytic cycle: the oxidative addition of an aryl halide to a Ni(I) species, the ligand exchange/transmetalation at a Ni(III) center, and the C–O reductive elimination from a Ni(III) species. Overall, the present work suggests theRN3 ligands are a practical platform for mechanistic studies of Ni-catalyzed reactions and for the development of new catalytic applications.
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In‐vitro and In‐vivo Photocatalytic Cancer Therapy with Biocompatible Iridium(III) Photocatalysts
Abstract Photocatalytic anticancer profile of a IrIIIphotocatalyst (Ir3) with strong light absorption, high turnover frequency, and excellent biocompatibility is reported.Ir3showed selective photo‐cytotoxicity against cisplatin‐ and sorafenib‐resistant cell lines while remaining dormant to normal cell lines in the dark.Ir3exhibited excellent photo‐catalytic oxidation of cellular co‐enzyme, the reduced nicotinamide adenine dinucleotide phosphate (NADPH), and amino acids via a single electron transfer mechanism. The photo‐induced intracellular redox imbalance and change in mitochondrial membrane potential resulted in necrosis and apoptosis of cancer cells. Importantly,Ir3exhibited high biocompatibility and photo‐catalytic anticancer efficiency as evident from in vivo zebrafish and mouse cancer models. To the best of our knowledge,Ir3is the first IrIIIbased photocatalyst with such a high biocompatibility and photocatalytic anticancer therapeutic effect.
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- Award ID(s):
- 1764264
- PAR ID:
- 10237077
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Angewandte Chemie International Edition
- Volume:
- 60
- Issue:
- 17
- ISSN:
- 1433-7851
- Format(s):
- Medium: X Size: p. 9474-9479
- Size(s):
- p. 9474-9479
- Sponsoring Org:
- National Science Foundation
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