Exploring aminium radical reactivity toward enol derivatives under photocatalytic conditions

The intermolecular addition of aminium radicals to enol derivatives offers a promising strategy for the synthesis of amino sugar derivatives. Inspired by recent advances in visible-light photocatalytic hydroamination, we are investigating different amine precursors as sources of aminium radicals for the functionalization of enol derivatives. The feasibility of this approach was demonstrated by reproducing the hydroamination of 4-methylpiperidine with 3,4-dihydro-2H-pyran in satisfactory yield. Building on these results, the methodology is being expanded to include nitrogen heterocycles and amino acid derivatives as alternative radical precursors. In parallel, glycals are being evaluated as carbohydrate-derived enol ethers to provide direct access to amino sugar derivatives. Preliminary results indicate that reaction efficiency is strongly influenced by substrate structure, highlighting the need for optimization of photocatalysts, reaction conditions, and protecting groups. These studies aim to establish a general platform for the photocatalytic functionalization of enol derivatives and expand the synthetic utility of aminium radical chemistry.