作者:Charles W. Rees、Tai-Yuen Yue
DOI:10.1039/b106384g
日期:2001.10.11
Trithiazyl chloride 1 converts the oximes of simple cyclic ketones into fused 1,2,5-thiadiazoles and bis-1,2,5-thiadiazoles in mild one-pot reactions. Cyclopentanone oxime gives the bisthiadiazole 3 (20%) in which all four methylene groups have been functionalised. Indan-1-one oxime 4 gives the thiadiazole 5 (63%), and tetralone oximes 6 and 8 give the bisthiadiazole 7 in low yields (20%) in complex reactions. Benzosuberone oxime 11 however gives only the monothiadiazole 12 (30%) which is not converted further with more trimer 1. These
reactions probably occur by mechanisms analogous to those proposed earlier for the conversion of alkenes, alkynes, active methylene compounds and enamines into 1,2,5-thiadiazoles. Bisthiadiazole 3, a reactive analogue of fluorene, condenses with p-anisaldehyde to give 13 and is oxidised by PCC to the fluorenone analogue 15 in low yield; 15 is formed directly from cyclopentane-1,3-dione with trimer 1. Ketone 15 condenses with malononitrile and Hünig's base to give the dicyanomethylene derivative 17 (94%) which forms a black metallic 1 ∶ 1 complex with TTF at room temperature.
Trithiazyl chloride 1 通过温和的单锅反应,将简单环酮的肟转化为融合的 1,2,5-噻二唑和双-1,2,5-噻二唑。环戊酮肟可以得到双噻二唑 3(20%),其中的四个亚甲基均已官能化。茚酮肟 4 可以生成噻二唑 5(63%),四氢萘酮肟 6 和 8 在复杂的反应中可以生成双噻二唑 7,但产率较低(20%)。然而,苯并环酮肟 11 只生成了单噻二唑 12(30%),而这种单噻二唑 12 在三聚体 1 的作用下无法进一步转化。这些反应的发生机理可能与之前提出的烯、炔、活性亚甲基化合物和烯胺转化为 1,2,5-噻二唑的机理类似。双噻二唑 3 是芴的活性类似物,它与对甲氧基苯甲醛缩合生成 13,并被 PCC 氧化为芴酮类似物 15,产率较低;15 是由环戊烷-1,3-二酮与三聚体 1 直接生成的。酮 15 与丙二腈和 Hünig 碱缩合,得到二氰亚甲基衍生物 17(94%),该衍生物在室温下与 TTF 形成黑色金属 1 ∶ 1 复合物。