647016-68-0Relevant articles and documents
Silver-mediated palladium-catalyzed direct C-H arylation of 3-bromoisothiazole-4-carbonitrile
Ioannidou, Heraklidia A.,Koutentis, Panayiotis A.
supporting information; experimental part, p. 1510 - 1513 (2011/05/04)
Silver(I) fluoride-mediated Pd-catalyzed C-H direct arylation/ heteroarylation of 3-bromoisothiazole-4-carbonitrile (1a) gives twenty-four 5-aryl/heteroaryl-3-bromoisothiazole-4-carbonitriles. The reaction was partially optimized with respect to catalyst, ligand, and base. During this study 3,3′-dibromo-5,5′-biisothiazole-4,4′-dicarbonitrile (3a) was isolated as a byproduct and subsequently prepared via the silver-mediated Pd-catalyzed oxidative dimerization of 3-bromoisothiazole-4-carbonitrile in 67% yield. The analogous phenylation and oxidative dimerization of 3-chloroisothiazole-4-carbonitrile (1b) gave 3-chloro-5-phenylisothiazole-4- carbonitrile (4) and 3,3′-dichloro-5,5′-biisothiazole-4,4′- dicarbonitrile (3b) in 96% and 69% yields, respectively.
Regiospecific Suzuki coupling of 3,5-dichloroisothiazole-4-carbonitrile
Christoforou, Irene C.,Koutentis, Panayiotis A.,Rees, Charles W.
, p. 2900 - 2907 (2007/10/03)
3,5-Dichloroisothiazole-4-carbonitrile 1 reacts with aryl- and methylboronic acids to give in high yields the 3-chloro-5-(aryl and methyl)-isothiazole-4-carbonitrile 2 regiospecifically. The reaction was optimized with respect to base, phase transfer agent and palladium catalyst. Suzuki coupling at C-5 was also achieved in high yield using potassium phenyltrifluoroborate. The regiospecificity of either coupling method is maintained with 3,5-dibromoisothiazole-4-carbonitrile 4 to give exclusively 3-bromo-5-phenylisothiazole-4-carbonitrile 5. Suzuki cross-coupling conditions applied to 3-chloro-5-phenylisothiazole-4-carbonitrile 2a gave 3-phenoxy-5-phenylisothiazole-4-carbonitrile 6, which was prepared independently, and not the 3-phenyl derivative. All isothiazole products were fully characterized.
