Visible-light mediated regioselective approach towards synthesis of 7-aroyl-6-methyl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines
作者:Ranjana Aggarwal、Shilpa Sharma、Mona Hooda、Dionisia Sanz、Rosa M. Claramunt、Brendan Twamley、Isabel Rozas
DOI:10.1016/j.tet.2019.130728
日期:2019.12
The first visible-light mediated, simple, efficient and ecofriendly protocol for the regioselective synthesis of novel [1,2,4]triazolo[3,4-b][1,3,4]thiadiazines has been developed by the reaction of α-bromodiketones, generated in situ by the bromination of a diverse array of β-diketones with N-bromosuccinimide, with 4-amino-[1,2,4]triazole-3-thiols. The methodology does not require the presence of
通过α的反应,开发了第一个可见光介导的,简单,有效和环保的方案,用于区域选择性合成新型[1,2,4]三唑[3,4- b ] [1,3,4]噻二嗪-溴代二酮,通过将各种不同的β-二酮与N溴化而原位生成-溴代琥珀酰亚胺,具有4-氨基-[1,2,4]三唑-3-硫醇。该方法不需要任何添加剂,并且该反应在EDG(OMe),EWG(Cl)和杂芳烃(thiophenyl)的存在下进行,从而以良好的收率获得了预期的产物。还建立了无溶剂方案以完成目标化合物的合成,但是它需要PTSA作为催化剂,收率相对较差。区域异构体的结构已通过异核2D-NMR [(1 H- 13 C)HMBC,(1 H- 15 N)HMBC,(1 H- 13 C)HMQC]光谱学和X射线晶体学研究得到了明确确认。