Tetracyanoanthraquinodimethanes with a chiral amide group: preparation, properties, and charge-transfer photochirogenetic reaction with 1,2-dianisylacenaphthene-1,2-diol.
Tetracyanoanthraquinodimethanes with a chiral amide group: preparation, properties, and charge-transfer photochirogenetic reaction with 1,2-dianisylacenaphthene-1,2-diol.
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DOI：
10.1021/jo0505324
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发表时间：
2005-06
期刊：
影响因子：
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通讯作者：
Takanori Suzuki;K. Ichioka;H. Higuchi;Hidetoshi Kawai;K. Fujiwara;M. Ohkita;T. Tsuji;Yasutake Takahashi-Yas
中科院分区：
文献类型：
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作者：
Takanori Suzuki;K. Ichioka;H. Higuchi;Hidetoshi Kawai;K. Fujiwara;M. Ohkita;T. Tsuji;Yasutake Takahashi-Yas
[反应：以相应的蒽醌为原料，合成了一系列带有手性酰胺助剂1a-f的蝶形四氰基蒽醌二甲烷（TCNAQs）。它们是比未取代的衍生物更强的受体，并且进行单波双电子还原。它们与标题频哪醇2形成弱的电子给体受体（EDA）络合物。在这些配合物的电荷转移激发下，有效地形成了二氢-TCNAQs 3和1，8-dianisoylnaphthalene 4，后者是retropinacol通过2+* 反应的产物。在CD 3CN中，rac-2与2-[（R）-1-苯乙基氨基甲酰基]-TCNAQ的光反应实现了部分对映体的分化。因此，从光解物中回收了光学活性的（S，S）-（+）-频哪醇2（在54%转化率下为12.3%ee;在70%转化率下为21.5%ee）。该反应代表了一个新的和罕见的叔醇的假动力学拆分伴随着C-C键断裂的例子。非对映体EDA复合物的缔合常数的显着差异是观察到的对映体分化的原因。
[reaction: see text] A series of butterfly-shaped tetracyanoanthraquinodimethanes (TCNAQs) with a chiral amide auxiliary 1a-f were prepared from the corresponding anthraquinones. They are stronger acceptors than the unsubstituted derivative and undergo one-wave two-electron reduction. They form weak electron-donor-acceptor (EDA) complexes with the title pinacol 2. Upon charge-transfer excitation of these complexes, dihydro-TCNAQs 3 and 1,8-dianisoylnaphthalene 4 were efficiently formed, the latter of which is the product of a retropinacol reaction via 2+*. Partial enantiodifferentiation of rac-2 was realized during the photoreactions with 2-[(R)-1-phenylethylcarbamoyl]-TCNAQ 1ain CD3CN. Thus, optically active (S,S)-(+)-pinacol 2 (12.3% ee at 54% conversion; 21.5% ee at 70% conversion) was recovered from the photolyzates. This reaction represents a new and rare example of the pseudokinetic resolution of tert-alcohol accompanied by C-C bond fission. Significant differences in the association constants for the diastereomeric EDA complexes are responsible for the observed enantiodifferentiation.