A palladium-catalyzed coupling reaction of aryl nonaflates, sulfur dioxide, and hydrazines
作者:Yuanyuan An、Hongguang Xia、Jie Wu
DOI:10.1039/c5ob02514a
日期:——
nonaflates, sulfurdioxide, and hydrazines is reported. This transformation proceeds in the presence of Pd(OAc)2/XantPhos, and TBAB in 1,4-dioxane at 80 °C, leading to the corresponding N-aminosulfonamides in moderate to good yields. The reaction scope has been demonstrated, and good functional tolerance is observed. A plausible mechanism is proposed through the insertion of sulfurdioxide.
Direct C3-Selective Arylation of N-Unsubstituted Indoles with Aryl Chlorides, Triflates, and Nonaflates Using a Palladium–Dihydroxyterphenylphosphine Catalyst
successfully applied to the direct C3-arylation of N-unsubstituted indoles with arylchlorides, triflates, and nonaflates. This catalyst showed C3-selectivity, whereas catalysts with other structurally related ligands exhibited N1-selectivity. Complex formation between the lithium salts of the ligand and the indole is assumed to accelerate the arylation at the C3 position. Reactions using 3-alkylindoles afforded
The photolysis of electron-rich aryl nonaflates (ArONfs) in protic media was investigated and heterolysis of the ArâOS bond (from 3ArONf) took place. The reaction generated a triplet phenyl cation that added to Ï-bond nucleophiles. This metal-free arylation method was made further useful by adopting in situ preparation of ArONf from the corresponding phenol.
Pyrroloindoline/Pyridoindoline Synthesis via C3-Dearomative Arylation/Cyclization of Tryptamine/Homotryptamine Derivatives Using Palladium–Dihydroxyterphenylphosphine Catalyst
C3-arylation of tryptaminederivatives with aryl nonaflates. The intramolecular cyclization of the resulting 3,3-disubstituted indolenines afforded C3a-arylated pyrroloindolines in one pot. We postulate that the formation of complexes between the lithium salts of DHTP and the tryptaminederivative is the key to promoting selective arylation at the C3-position of the indole ring. Furthermore, reactions using
We developed a Pd-catalyzeddecarboxylativecross-coupling of zinc polyfluorobenzoates, which were used as precursors for producing zinc reagents in situ, with aryl bromides and nonaflates, providing a mild and efficient pathway for the synthesis of polyfluorinated biaryls. This protocol exhibits a broad substrate scope and excellent functional tolerance. Moreover, the versatility of this approach