A Novel Coupling 1,3-Dipolar Cycloaddition Sequence as a Three-Component Approach to Highly Fluorescent Indolizines
作者:Alexandru V. Rotaru、Ioan D. Druta、Thomas Oeser、Thomas J. J. Müller
DOI:10.1002/hlca.200590141
日期:2005.7
Indolizines 4 and biindolizines 6 can be synthesized in moderate yields in a consecutive one-pot three-component process by a coupling/1,3-dipolar cycloaddition sequence of a (hetero)arenecarbonyl chloride 1, a terminal alkyne 2, and a suitable 1-(2-oxoethyl) pyridinium bromide 3 or 5, respectively (Schemes 1 and 2). After the Sonogashira coupling, a [2+3] cycloaddition of the in situ formed pyridinium
吲哚嗪4和联吲哚嗪6可以通过(杂)芳烃羰基氯1,末端炔烃2和合适的1的偶合/ 1,3-偶极环加成序列,以连续的一锅三组分法以中等收率合成。-(2-氧乙基)吡啶鎓溴化物3或5(方案1和2)。在Sonogashira耦合之后,原位[2 + 3]环加成形成的吡啶鎓内鎓盐(一种烯丙基型1,3偶极子)提供了一种环加合物,该环加合物被瞬间氧化芳构化,以给出高荧光的吲哚嗪衍生物,其明确地由化合物4d的X射线结构分析表征(图1)。另外,用吡啶基取代的代表进行的荧光研究不仅表明吲哚嗪和联吲哚嗪是非常有趣的荧光染料,而且它们的荧光颜色也可以在改变培养基的pH值时可逆地转换。