Alternatives to Iridium: A Polyaza[7]helicene as a Strongly Reductive Visible Light Photoredox Catalyst was written by Rocker, Johannes;Opatz, Till. And the article was included in ACS Organic & Inorganic Au in 2022.Electric Literature of C7H6N2 This article mentions the following:
The use of a readily accessible polyazahelicene as a strongly reducing metal-free alternative to the commonly used precious metal based photo redox catalysts is demonstrated. An improved two-step synthesis of the catalyst is described, and its photophys. properties with respect to its use as a photo redox catalyst are evaluated. Its activity under visible light irradiation is proven by application in two double radical light-driven multi-component reactions. The azahelicene gave comparable results to an iridium-based catalyst originally used for the same transformations. In the experiment, the researchers used many compounds, for example, 4-Methylpicolinonitrile (cas: 1620-76-4Electric Literature of C7H6N2).
4-Methylpicolinonitrile (cas: 1620-76-4) belongs to pyridine derivatives. Pyridines are an important class of heterocycles and occur in polysubstituted forms in many naturally occurring biologically active compounds, drug molecules and chiral ligands. Pyridine groups exist in countless molecules, and their applications include catalysis, drug design, molecular recognition, and natural product synthesis.Electric Literature of C7H6N2