Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations |
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Authors: | Christoph Fricke Kristina Deckers Prof?Dr Franziska Schoenebeck |
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Institution: | Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany |
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Abstract: | While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism. |
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Keywords: | chemoselectivity germanium halogenation reaction mechanisms synthetic methods |
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