Radical homolysis of pyridine-based Breslow-like enaminols

by Kubik, Jacklyn; Barrett, Justin; McIntosh, Matt

We have found that Breslow intermediates derived from condensation of aromatic aldehydes and appropriately substituted N-heterocyclic carbenes undergo C-N sigma bond homolysis at temperatures as low as ambient (https://doi.org/10.1002/anie.201508368). The geminate radical pair so generated principally undergoes recombination to give products of formal 1,3-rearrangement. DFT calculations suggested that this phenomenon may occur with other related heterocyclic structures. We report that pyridine-based Breslow-type enaminols likewise engage in the same reaction pathway. We will present our results in extending this reactivity to substrates derived from 2-hydroxymethyl pyridines.