We successfully developed a decatungstate-catalyzed benzylic C(sp3)-H alkylation of sulfonanilides by utilizing the hydrogen bond between the sulfonamide group of the substrates and decatungstate photocatalysts. Using this catalytic system, site-selective C(sp3)-H alkylation was achieved at the benzylic position near the sulfonamide group.
This work presents a systematic and rational approach to the synthesis of previously reported as well as novel tetra- and di-ortho-borylated perylene, perylenediimide, and perylenemonoimide scaffolds. Through optimization of the reaction conditions, employing [Ir(OMe)(COD)]2 as a catalyst and suitable ligands, efficient tetraborylation and regioselective diborylations were achieved. Additionally, the reaction times were reduced from days to hours under microwave irradiation, rendering this methodology a practical and scalable route for the ortho-functionalization of perylene derivatives.
Despite the widespread ortho-functionalization of cyclic diaryliodoniums in organic chemistry, the corresponding meta-functionalization is less explored. Herein, we report a practical meta-selective activation of cyclic hypervalent iodoniums for the synthesis of 4-amino coumarin derivatives in a broad functional group tolerance and environmentally friendly manner. The practicability of this protocol was further highlighted by the late-stage modification of some common pharmaceuticals and natural products.
As cationic functional groups with excellent alkaline resistance that are potentially applicable to building blocks of robust anion exchange membrane (AEM) materials for water splitting and fuel cell modules, we describe the synthesis of triarylsulfonium (TAS) salts bearing sterically demanding substituents by the reaction of arynes with diaryl sulfides/sulfoxides and by the Friedel-Crafts reaction of diaryl sulfoxides. The TAS cations possessing three substituted benzene rings, such as tris(2,5-dimethylphenyl)sulfonium and bis(2,5-dimethylphenyl)mesitylsulfonium, were effectively produced through the appropriate choice of reactions and reagents. The alkaline stability of the TAS cations thus obtained was evaluated from their time-course 1H NMR spectra in 1 M KOH/CD3OD, from which the alkaline resistance of the TAS cations increased dramatically as the steric bulkiness of the aromatic substituents attached to the TAS cations increased. Among them, bis(2,5-dimethylphenyl)mesitylsulfonium was found to exhibit 25 times higher alkaline resistance performance compared to benzyltrimethylammonium, a conventional quaternary ammonium cation. The decomposition mechanism of the TAS cations in the basic methanol media was studied in detail, and it was concluded that the decomposition occurred by the nucleophilic ipso-substitution by the methoxide anions.
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：