Tetracyanoanthraquinodimethanes with a Chiral Amide Group: Preparation, Properties, and Charge-Transfer Photochirogenetic Reaction with 1,2-Dianisylacenaphthene-1,2-diol
作者:Takanori Suzuki、Koji Ichioka、Hiroki Higuchi、Hidetoshi Kawai、Kenshu Fujiwara、Masakazu Ohkita、Takashi Tsuji、Yasutake Takahashi
DOI:10.1021/jo0505324
日期:2005.7.1
(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 1a in CD3CN. Thus, optically active (S,S)-(+)-pinacol
由相应的蒽醌制备了一系列具有手性酰胺助剂1a - f的蝴蝶形四氰基蒽醌二甲烷(TCNAQ)。它们比未取代的衍生物更强受体,并且经历一波两电子还原。它们与标题频哪醇2形成弱电子供体受体(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-TCNAQ 3和1,8-双异萘基萘4,后者是通过2 + •进行的频哪酚反应的产物。部分enantiodifferentiation消旋- 2在与CD 3 CN中的2-[(R)-1-苯基乙基氨基甲酰基] -TCNAQ 1a进行光反应的过程中实现了“α” 。因此,从光解产物中回收了旋光的(S,S)-(+)-频哪醇2(54%转化率的12.3%ee; 70%转化率的21.5%ee)。该反应代表了伴随着CC键裂变的叔醇假动力学拆分的一个新的和罕见的例子。非对映体EDA复合物缔合常数的显着差异是所观察到的对映异构化的原因。