These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
Mimicking Noncanonical Oxidations with Redox-Neutral Photocatalysis
preprintsubmitted on 29.08.2019, 03:30 and posted on 30.08.2019, 14:29 by Zheng Huang, Jean-Philip Lumb
Noncanonical oxygenases are a family of Fe-containing enzymes that catalyze oxidative radical cyclizations. Despite creating key structural features that often define a natural product’s complexity, the mechanisms of these oxidations remain poorly understood and difficult to mimic. In this work, we show that noncanonical cyclizations from lignan biosynthesis can be recreated when presumed biosynthetic radicals are generated using photocatalysis. These conditions afford the ensuing electron rich radicals sufficient time to undergo challenging 5- or 11-membered ring formation that create the defining structural features of the highly oxidized lignans taiwankadsurins A, B and kadsuphilin N. By showing that these cyclizations can occur without enzymatic assistance, we provide a more general strategy for mimicking noncanonical transformations that should broaden their use in organic synthesis.