Photoinduced Electron Transfer Reactions in Chiral Reaction Media

本课题的研究结果如下：1.在S-（+）-和R-（-）-2，2 '-二甲基-1，1'-联蒽（1a和1b）的荧光猝灭中观察到手性识别。猝灭速率根据猝灭剂的结构、给电子能力和手性而变化。发现最大的手性区分是通过对映体对（+）-和（-）-N-（α-甲基苄基）-2，5-二甲基吡咯在1a的荧光猝灭中发现的。在由1a和芳香胺如二甲基苯胺（2）产生的发射激基复合物的荧光猝灭中也观察到手性歧视。肉桂酸薄荷酯在苯中对1a/2和1b/2体系激基复合物的荧光猝灭的kqtau比有最大值，为1.08，并随溶剂极性的增大而减小。这些结果表明，手性猝灭剂与手性激基复合物的相互作用具有对映选择性.研究了手性敏化剂1，4-二氰基萘和9，10-二氰基蒽催化的醇与芳基烯烃的光化学极性加成反应。由2-胆甾烷氧基甲基-1，4-二氰基萘敏化的甲醇与1，1-二苯基丙烯的反马氏加成反应显示出最大值，27%的对映体过量。呋喃与萘环1-或2，3-位上具有手性烷氧羰基的萘衍生物之间的分子内和分子间光环加成反应分别以非对映选择性方式得到（4+4）环加合物和笼状化合物。此外，它揭示了区域化学的产品是由激基复合物的偶极矩。

The title subject was investigated and the following results were obtained :1. Chiral discrimination is observed in the fluorescence quenching of S- (+) -and R- (-) -2,2'-dimethyl-1,1'-bianthryls (1a and 1b) by a variety of chiral quenchers. Quenching rates are varied depending on the structures, electron-donating abilities, and chiralities of the quenchers. The largest chiral discrimination is found in the fluorescence quenching of 1a by the enantiomer pair (+) -and (-) -N-(alpha-methylbenzyl) -2,5-dimethylpyrrole.2. Chiral discrimination is also observed in the fluorescence quenching of emissive exciplexes generated from 1a and aromatic amines such as dimethylaniline (2) by chiral quenchers. The kqtau ratio in the fluorescence quenching of the exciplex emission of 1a/2 and 1b/2 systems by (+) -menthyl cinnamate in benzene shows a maximum value of 1.08, and is decreased with increasing polarity of solvents. These results indicate that the chiral quenchers interact with chiral exciplexes in a enantioselective manner.3. Photochemical polar additions of alcohols to arylalkenes catalyzed by chiral sensitizers such as 1,4-dicyanonaphthalene and 9,10-dicyanoanthracene bearing menthyl and cholesteryl group are investigated. Anti-Markovnikov addition of methanol to 1,1-diphenylpropene sensitized by 2-cholesteryloxymethyl-1,4-dicyanonaphthalene shows a maximum value, a 27% enantiomeric excess.4. Inter- and intramolecular photocycloadditions between furan and naphthalene derivatives having chiral alkoxycarbonyl group (s) at 1- or 2,3-position (s) of naphthalene ring give (4+4) cycloadducts and cage compounds in a diastereoselective manner, respectively. Moreover, it is revealed that the regiochemistry of products is governed by dipolar moments of exciplexes.