2818-88-4Relevant articles and documents
Di- tert-butyl Peroxide-Mediated Radical C(sp2/sp3)-S Bond Cleavage and Group-Transfer Cyclization
Luo, Kai,Yang, Wen-Chao,Wei, Kai,Liu, Yue,Wang, Jun-Ke,Wu, Lei
supporting information, p. 7851 - 7856 (2019/10/11)
A novel strategy of cascade radical C(sp2/sp3)-S bond cleavage and group-transfer cyclization is disclosed. Triggered by alkyl radicals, varieties of 2-isocyanoaryl thioethers containing aliphatic, aryl, and heteroaromatic groups can be cleaved and precisely reinstalled to give benzothiazole derivatives. Mechanistic studies reveal that the cascade reaction undertakes an intermolecular pathway, and the inner radical sources (R radicals) exhibit high priority over those of methyl radical origin from di-tert-butyl peroxide.
Reactivity of Heterocyclic Nitrogen Donors in Systems containing the Tetrachloroaurate(III) Anion
Canovese, Luciano,Cattalini, Lucio,Tomaselli, Michele,Tobe, Martin L.
, p. 307 - 314 (2007/10/02)
A series of gold(III) complexes of the type has been prepared and characterized (L = oxazole, benzoxazole, thiazole, their benzo and methyl-substituted derivatives, or 2-methylbenzoselenazole).The five-membered N.O-, N,S- and N,Se-heterocyclic bases are all bound to Au(III) through nitrogen.The kinetics of the displacement of L by chloride to give (1-) has been studied in methanol-water (95:5. v/v) at 25.0 deg C and I = 0.20 mol dm-3 (LiClO4).The equilibrium constants for the reversible processes have also been determined.The reactions of the corresponding pyridine, 4-chloro-, 4-cyano- and 2,6-bis(chloromethyl)-pyridine complexes have also been reexamined under the same conditions.The equlibrium constants, K2, depend upon the basicity of the nitrogen in the ligands and points for all ligands, irrespective of ring size and composition, lie roughly on the same log K2 versus pKa curve.There is no significant systematic steric effect on the equilibrium constants of the sort found for the more basic methyl pyridines.The complexes of the five-membered heterocyclic ligands are approximately ten times less reactive than those of the six-membered N-heterocycles of comparable basicity and exhibit steric retardation from ortho-methyl substituents.The nucleophilicities of these ligands have been calculated and five-membered N,O- and N,S-heterocycles are considerably less reactive than six-membered N-heterocycles of similar basicity.
Novel Benzyne Additions to the 1,2,5-Thiadiazole and 1,2,5-Selenadiazole Ring Systems
Bryce, Martin R.,Hanson, Peter,Vernon, John M.
, p. 299 - 300 (2007/10/02)
Novel modes of benzyne addition to 3,4-dimethyl-1,2,5-thiadiazole and 3,4-dimethyl-1,2,5-selenadiazole afford methyl derivatives of three heterocyclic systems: quinoxaline, 1,2-benzisothiazole, and 1,3-benzoselenazole respectively.