Transition Metal Free Cycloamination of Prenyl Carbamates and Ureas Promoted by Aryldiazonium Salts |
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Authors: | Roman Abrams Dr Quentin Lefebvre Prof Jonathan Clayden |
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Institution: | School of Chemistry, University of Bristol, Bristol, UK |
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Abstract: | Upon treatment with aryldiazonium salts, prenyl carbamates and ureas undergo redox‐neutral azocycloamination. In general, N‐aryl O‐prenyl carbamates cyclize in a photocatalytic reaction with visible light and an organic dye. With electron‐deficient diazonium salts, electronic matching with an electron‐rich N‐aryl substituent results in a reaction proceeding in the ground state, without either light or photocatalyst. Cyclic voltammetry suggests that this radical reaction is initiated by hydrogen‐atom abstraction mediated by an aryl radical, followed by a radical addition cascade and proton‐coupled hole propagation. The reaction proceeds at room temperature in short reaction times, and a range of functional groups is tolerated. |
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Keywords: | amination cyclizations diazonium salts heterocycles radicals |
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