Efficient synthesis of 4-sulfanylcoumarins from 3-bromo-coumarins<i>via</i>a highly selective DABCO-mediated one-pot thia-Michael addition/elimination process
作者:Vitor B. Mostardeiro、Marina C. Dilelio、Teodoro S. Kaufman、Claudio C. Silveira
DOI:10.1039/c9ra09545d
日期:——
was developed. The transformation took place with aromatic and aliphatic thiols as well as with α,ω-dithiols, affording the expected products in very good to excellent yields. Simple and convenient ways to access 4-((ω-mercaptoalkyl) thio)coumarins and the dimeric 4,4′-(alkane-1,4-diylbis(sulfanediyl))bis(coumarins) were also devised with the use of α,ω-alkanedithiols in different ratios with regards
开发了一种在 DABCO 促进下对 3-溴香豆素进行高选择性直接硫酰化的简便有效的方案。使用芳香族和脂肪族硫醇以及 α,ω-二硫醇进行转化,以非常好的至极好的产率提供预期的产物。还设计了使用 α 获得 4-((ω-巯基烷基)硫代)香豆素和二聚 4,4'-(烷烃-1,4-二基双(硫烷二基))双(香豆素)的简单方便的方法,与起始 3-溴香豆素有关的不同比例的 ω-烷二硫醇。转化似乎是通过 DABCO 介导的硫醇盐阴离子向香豆素的 α,β-不饱和羰基体系中的立体选择性加成,然后对所得的 α-溴羰基中间体进行 DABCO 辅助立体选择性脱溴氢反应来进行的。