A Case Of Chain Propagation: Alpha-Aminoalkyl Radicals As Initiators For Aryl Radical Chemistry

The generation of aryl radicals from the corresponding halides by redox chemistry is generally considered a difficult task due to their highly negative reduction potentials. Here we demonstrate that alpha-aminoalkyl radicals can be used as both initiators and chain-carriers for the radical coupling of aryl halides with pyrrole derivatives, a transformation often employed to evaluate new highly reducing photocatalysts. This mode of reactivity obviates for the use of strong reducing species and was also competent in the formation of sp(2) C-P bonds. Mechanistic studies have delineated some of the key features operating that trigger aryl radical generation and also propagate the chain process.