Energy-Transfer-Powered Sultine Synthesis

Abstract

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.

Catalytic asymmetric [4 + 2] dearomative photocycloadditions of anthracene and its derivatives with alkenylazaarenes

“…Consequently, at −35 °C with irradiation by three 3 W blue LEDs, 3a could be achieved in 83% yield with 90% ee when employing 10 mol% ( S )-SPINOL-derived N -triflyl-phosphoramide C1 in dichloromethane as the solvent within 36 h (entry 1, Table 1 ). Other photosensitizers were then evaluated, such as Eosin Y ( E T = 39.7 kcal/mol) 32 , Rose Bengal ( E T = 40.9 kcal/mol) 33 , 4CzIPN ( E T = 57.1 kcal/mol) 32 , Ir(ppy) 3 ( E T = 57.8 kcal/mol) 33 and (Ir[dF(CF 3 )ppy] 2 (dtbbpy))PF 6 ( E T = 60.8 kcal/mol) 33 (entries 2 − 6). The results clearly show that the photosensitizers with higher triplet energy (entries 4 − 6), but not lower (entries 2 − 3), than 1a can allow for a smooth conversion.…”

Comprehensive Insight into Construction of Active Sites toward Steering Photocatalytic CO2 Conversion

“…The generated FLPs can act as catalytic sites to adsorb, activate, and convert CO 2 . Moreover, the surface hydroxyl can self‐replenish by dissociating H 2 O during the reaction, achieving a long‐term CO 2 conversion up to 60 h. [ 71 ] Isomorphic substitution of Ca 2+ ions by Cu 2+ ions especially at very low levels of exchange creates new analogs of molecular surface FLPs in Cu x Ca 10−x (PO 4 ) 6 (OH) 2 , being defined as proximal Lewis acidic Cu 2+ and Lewi's basic OH − . The unique catalytically active surface boosts heterogeneous CO 2 photocatalytic hydrogenation.…”

Thermoinduced Radical Cyclization for the Synthesis of Sultines

“…In 2019, Alemán, Maestro, and co-workers discovered an intramolecular homolytic substitution cyclization of aryl halides under near UV light for benzo-fused sultine synthesis . In 2023, Shu and co-workers demonstrated two photoinduced sultine constructions through radical–polar crossover cyclization and energy-transfer-enabled radical–radical crossover coupling, respectively . Compared with photocatalysis, thermoinduced radical cyclization is an important and indispensable strategy for sultine assembly; however, most of these methods hinge on the use of very harsh conditions and are limited to the availability of starting materials, which are incompatible with certain functional groups.…”