Yoshiaki Nishibayashi and co-workers at the University of Tokyo have reported in JACS on the use of an iridium photocatalyst to form alpha-aminoalkyl radicals.
What is photoredox catalysis anyway? I have always been turned away from this kind of reaction because it always looked like people lit up a light bulb right next to their reactions to run these reactions, but I guess more and more people are starting to develop it. People use a catalyst with a special ligand that allows it to undergo a metal to ligand charge transfer in the presence of low energy visible light. The excited catalyst accepts an electron from a donor source (such as Hunig’s base). This may be the reaction of 2012.
Hien Nguyen and co-workers from the University of Illinois have reported in JACS on a fluorination reaction using iridium. This substrate is a trichloroacetimidate that is usually found as a substrate in the Overman rearrangement.
Corey Stephenson and colleague at Boston University have reported in Organic Letters on an iridium catalyzed tandem reaction using visible light – the reaction forms a divinyl cyclopropane intermediate that undergoes a Cope rearrangement.
Belen Martin Matute and co-workers at Stockholm University have reported in Synthesis on the transformation from an allylic alcohol to an alpha-fluoroketone using an iridium catalyst and Selectfluor as the fluorinating agent.