The Reduction of Oxalic Amidines with Metallic Lithium: Preparation of Lithiated Bisamides [R″N(RR′N)C=C(NRR′)NR″]Li
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and Their Use as Intermediates in a Novel Synthesis of Tetraaminoethenes
作者:Matthias Wenzel、Dirk Lindauer、Rainer Beckert、Roland Boese、Ernst Anders
DOI:10.1002/cber.19961290110
日期:1996.1
amidines with lithium metal yields the new lithium diamides 3. Subsequent reaction of 3 with various electrophiles gives the title substances 4, 5, and the acylated derivative 6, respectively. The first SET step in this reaction is the formation of monolithium radical anions 2, which were detected by EPR spectroscopy. The second electron transfer leads to the deeply colored dianions 3. – In the case
用锂金属还原六取代的草am的1,4-二氮杂1,3-丁二烯亚结构产生了新的二酰胺锂3。3与各种亲电试剂的后续反应分别得到标题物质4、5和酰化衍生物6。该反应的第一个SET步骤是形成单锂自由基阴离子2,可通过EPR光谱法对其进行检测。二次电子转移导致深色的双价阴离子3。-在化合物的情况下3A [顺式-图3a ·3的Et 2 O],在X射线晶体结构揭示了cisoid在锂阳离子的第一个配位域中,将二齿配体和三个乙醚分子以2:1的方式排列。在[D 10 ]乙醚/二乙醚(8:1)中3a的NMR 2D- 1 H,6 Li-HOESY研究表明,Li +与醚分子的氢原子和与该分子的邻氢原子接触芳基部分。半经验计算(PM3)的结果与实验数据完全一致,可以解释化合物3的锂阳离子的不同配位模式。