Energy-Transfer-Powered Sultine Synthesis

Molecules with precise sultine structures are particularly sought after since the function of a molecule depends on this interesting structure. Despite the positive pivotal significance of the sultines in synthesis, medicine, and materials science, the sultines' chemistry long remains unexplored due to their inaccessibility; only very limited protocols have been developed. Here, we report an energy-transfer-powered intramolecular radical–radical cross-coupling cyclization for the practical and atom-economical assembly of otherwise challenging-to-access sultines under mild and operationally simple conditions using an inexpensive organic photocatalyst. Importantly, this work presents a practical method of trifluoromethyl radical generation from alkyl trifluoromethanesulfinate, and the obtained sultines were confirmed as promising electrolyte additives for high-voltage lithium batteries employing LiNi0.5Mn1.5O4 cathodes and carbonate electrolytes. Sultines were applied to build highly valuable sultones, mercaptoalkanols, and disulfides. Mechanistic studies and density functional theory calculations supported that the reaction likely proceeds through an energy-transfer-powered radical–radical cross-coupling cyclization process.