About the Seminar:
Nitroarenes are an important class of molecules found in pharmaceuticals and used as synthetic intermediates in the synthesis of more complex molecules. Because nitroarenes are very pi-deficient, they are challenging to halogenate via electrophilic aromatic substitution (EAS). Currently, these molecules can be halogenated at the meta position using solvent quantities of strong acids and high temperatures, which can be incompatible with many potential starting materials. Methods to halogenate the ortho and para positions are rare and these nitroarene products are particularly in demand as they will further react with nucleophiles via nucleophilic aromatic substitution pathways. The purpose of this proposal is to develop strategies to facilitate electrophilic halogenation of nitroarenes at all possible positions. The proposed reactions operate via two distinct reaction platforms that effectively enhance the nucleophilicity of nitroarenes. Specific Aim 1 describes a dearomatization strategy, while Specific Aims 2 and 3 describe a method that temporarily derivatizes a nitro group to a 1,3,2-dioxazolidine ring. These methods would improve access to halogenated nitroarenes, and the proposed reaction platforms can potentially be expanded to electrophiles other than halogens, enabling a diverse set of reactions.