In 2022,Bawden, Joseph C.; Francis, Paul S.; DiLuzio, Stephen; Hayne, David J.; Doeven, Egan H.; Truong, Johnny; Alexander, Richard; Henderson, Luke C.; Gomez, Daniel E.; Massi, Massimiliano; Armstrong, Blake I.; Draper, Felicity A.; Bernhard, Stefan; Connell, Timothy U. published an article in Journal of the American Chemical Society. The title of the article was 《Reinterpreting the Fate of Iridium(III) Photocatalysts-Screening a Combinatorial Library to Explore Light-Driven Side-Reactions》.Electric Literature of C7H3BrFN The author mentioned the following in the article:
Photoredox catalysts are primarily selected based on ground and excited state properties, but their activity is also intrinsically tied to the nature of their reduced (or oxidized) intermediates. Catalyst reactivity often necessitates an inherent instability, thus these intermediates represent a mechanistic turning point that affords either product formation or side-reactions. In this work, we explore the scope of a previously demonstrated side-reaction that partially saturates one pyridine ring of the ancillary ligand in heteroleptic iridium(III) complexes. Using high-throughput synthesis and screening under photochem. conditions, we identified different chem. pathways, ultimately governed by ligand composition The ancillary ligand was the key factor that determined photochem. stability. Following photoinitiated electron transfer from a sacrificial tertiary amine, the reduced intermediate of complexes containing 1,10-phenanthroline derivatives exhibited long-term stability. In contrast, complexes containing 2,2′-bipyridines were highly susceptible to hydrogen atom transfer and ancillary ligand modification. Detailed characterization of selected complexes before and after transformation showed differing effects on the ground and excited state reduction potentials dependent on the nature of the cyclometalating ligands and excited states. The implications of catalyst stability and reactivity in chem. synthesis was demonstrated in a model photoredox reaction. The results came from multiple reactions, including the reaction of 4-Bromo-2-fluorobenzonitrile(cas: 105942-08-3Electric Literature of C7H3BrFN)
4-Bromo-2-fluorobenzonitrile(cas:105942-08-3) is used as a reagent in the synthesis of picolinamide derivatives as a novel class of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors.Electric Literature of C7H3BrFN 4-Bromo-2-fluorobenzonitrile is also used in the preparation of fluorinated CB2 receptor agonists for PET imaging.
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts