575-26-8Relevant articles and documents
Te(II)-Catalyzed Cross-Dehydrogenative Phenothiazination of Anilines
Cremer, Christopher,Patureau, Frederic W.,Vemuri, Pooja Y.
supporting information, p. 1626 - 1630 (2022/03/14)
Oxidative clicklike reactions are useful for the late-stage functionalization of pharmaceuticals and organic materials. Hence, novel methodologies that enable such transformations are in high demand. Herein we describe a tellurium(II)-catalyzed cross-dehydrogenative phenothiazination (CDP) of aromatic amines. A key feature of this method is a cooperative effect between the phenotellurazine catalyst and the silver salt, which serves as a chemical oxidant for the reaction. This novel catalysis concept therefore enables a considerably broader scope compared with previous chemical oxidation methods.
Well-Designed N-Heterocyclic Carbene Ligands for Palladium-Catalyzed Denitrative C-N Coupling of Nitroarenes with Amines
Chen, Kai,Chen, Wanzhi,Chen, Wei,Liu, Miaochang,Wu, Huayue
, p. 8110 - 8115 (2019/08/26)
The C-N bond formation is one of the fundamental reactions in organic chemistry, because of the widespread presence of amine moieties in pharmaceuticals and biologically active compounds. Palladium-catalyzed C-N coupling of haloarenes represents one of the most efficient approaches to aromatic amines. Nitroarenes are ideal alternative electrophilic coupling partners, since they are inexpensive and readily available. The denitration and cross-coupling using nitroarenes as the electrophilic partners is challenging, because of the low reactivity of the Ar-NO2 bond toward oxidative addition. We report here the C-N coupling of nitroarenes and amines using palladium/5-(2,4,6-triisopropylphenyl)imidazolylidene[1,5-a]pyridines as the catalyst. The ligands are readily available from commercial chemicals. The reaction shows broad substrate scope and functional group tolerance. The method is applicable to both aromatic and aliphatic amines, and many secondary and tertiary aromatic amines bearing various functional groups were obtained in high yields.
Facile synthesis and characterization of naphthidines as a new class of highly nonplanar electron donors giving robust radical cations
Desmarets, Christophe,Champagne, Benoit,Walcarius, Alain,Bellouard, Christine,Omar-Amrani, Rafik,Ahajji, Abdelaziz,Fort, Yves,Schneider, Raphael
, p. 1351 - 1361 (2007/10/03)
Naphthidines 2 were prepared by nickel-catalyzed amination of 1-chloronaphthalene followed by oxidative homocoupling of 1-naphthalene amines 1 using titanium(IV) tetrachloride. The electronic and magnetic properties of materials 2 were investigated by cyclic voltammetry and other electrochemical techniques, EPR and UV-visible spectroscopies, and magnetic susceptibility. It was demonstrated that compounds 2 could be easily and reversibly oxidized via a two-electron-transfer reaction into their bis(radical cation) 22.2+, which displays a substantial stability at room temperature (the half-life of 22.2+ estimated by EPR at 25 °C was 10 days). B3LYP/6-31G* optimized structures of N,N′-bis(4-methoxyphenyl)-(1,1′-binaphthyl)- 4,4′-diamine 2g shows significant differences in the torsion angle between the naphthalene moieties depending on its oxidation state. Twisted structures are preferred for neutral compounds, whereas more planar are favored for the oxidized forms 2g+ and 2g2.2+ to realize spin and/or charge delocalizations over the whole π-system. Such conformation changes concerted with the electron transfers contribute to explain the unusual two-electron process observed in the electrochemical behavior of 2g instead of the two single-electron transfers that would have been expected in the case of two successive oxidations. It is finally shown that the oxidation of 2g in CH2Cl2 with thianthrenium perchlorate (ThClO4) generates the dication 2g2.2+ with singlet spin-multiplicity.
