The Parasram Lab reported the facile, intermolecular synthesis of phenanthrenes from styrenes and aryl iodides using visible light, which can serve as a practical alternative to classical methods to create unsymmetrical moieties hosting varying functionalities. The work, entitled “Cascade Synthesis of Phenanthrenes under Photoirradiation” was published in the Journal of Organic Chemistry. The contributing authors include co-first authors Yongkang Li and Dr. Dan Wise, second author Mr. Joshua Mitchell, and Principal Investigator Assistant Professor Marvin Parasram. Click here to read the full article in JOC.
Abstract: We report a photoinduced phenanthrene synthesis from aryl iodides and styrenes through an arylation/cyclization cascade. Compared to prior methods, this approach obviates the need for hazardous reagents and provides access to unsymmetrical phenanthrenes with good functional group tolerance. Mechanistic studies revealed that photoexcitation of aryl iodides leads to homolytic C–I bond cleavage. Arylation of styrenes with the formed aryl radical species furnishes stilbene derivatives, which undergo photoinduced cyclization promoted by iodine generated in situ to yield phenanthrene products.