Synthesis of 3-Alkyl-4-aryl- and 3,4-Diaryl-1,2,5-thiadiazoles via Palladium-catalyzed Cross-Coupling Reaction
摘要:
4-Substituted 3-aryl-1,2,5-thiadiazoles were synthesized by palladium-catalyzed cross-coupling reaction of arylstannane with easily available 4-substituted 3-halogeno- and 3-trifluoromethylsulfonyloxy-1,2,5-thiadiazoles.
Synthesis of 3-Alkyl-4-aryl- and 3,4-Diaryl-1,2,5-thiadiazoles via Palladium-catalyzed Cross-Coupling Reaction
摘要:
4-Substituted 3-aryl-1,2,5-thiadiazoles were synthesized by palladium-catalyzed cross-coupling reaction of arylstannane with easily available 4-substituted 3-halogeno- and 3-trifluoromethylsulfonyloxy-1,2,5-thiadiazoles.
Reactions of 1-aryl-2,2-dihalogenoethanone oximes with tetrasulfur tetranitride (S4N4): a general method for the synthesis of 3-aryl-4-halogeno-1,2,5-thiadiazoles
作者:Sung Cheol Yoon、Jaeeock Cho、Kyongtae Kim
DOI:10.1039/a704408i
日期:——
on the basis of 1H NMR spectroscopic evidence and an X-ray crystallographic analysis of 1-(3-chlorophenyl)-2,2-dichloroethanone oxime 7f. The 1-aryl-2,2-dihalogenoethanone oximes react with tetrasulfurtetranitride in refluxing 1,4-dioxane to give 3-aryl-4-chloro-1, 3-aryl-4-bromo-2, and 3-aryl-4-fluoro-1,2,5-thiadiazoles 3 in 69–98, 49–99, and 32–65% yields, respectively. A mechanism for the formation
1-芳基-2,2-二氯-7、1-芳基-2,2-二溴-8、1-芳基-2-溴-2-氟-9和1-芳基-2-氯-2-氟-通过在室温下在EtOH中使相应的酮与盐酸羟胺反应来制备乙酮肟10。在1 H NMR光谱证据和1-(3-氯苯基)-2,2-二氯乙酮肟7f的X射线晶体学分析的基础上,对肟进行立体化学分配。1-芳基-2,2-二卤代乙酮肟与四氮化四硫反应,回流1,4-二恶烷,得到3-芳基-4-氯-1、3-芳基-4-溴-2和3-芳基-4 -氟-1,2,5-噻二唑3的产率分别为69-98、49-99和32-65%。提出了形成1,2,5-噻二唑的机理。
Reactions of Monohalomethyl Aryl Ketoximes with Tetrasulfur Tetranitride: Much Improved Synthesis of 3-Aryl-1,2,5-thiadiazoles
作者:Kyongtae Kim、Jaeeock Cho
DOI:10.3987/com-94-6755
日期:——
Reactions of chloromethyl aryl ketoximes (1, X = Cl) with tetrasulfur tetranitride in p-dioxane at reflux for 4 h afforded 3-aryl-1,2,5-thiadiazoles (2) in 37-92% yields, whereas those of bromo analogs under the same conditions gave 2 and 3-aryl-4-bromo-1,2,5-thiadiazoles (3) in 48-81% and 17-31% yields, respectively. However, the compounds (3) were not formed in the presence of pyridine. Alpha-nitrosostyrene and its ring-substituted derivatives (4) are proposed as intermediates for the formations of 2.
Kim Kyongtae, Cho Jaecock, Heterocycles, 38 (1994) N 8, S 1859-1866