Photoinduced Electron Transfer Reactions in Chiral Reaction Media

手性反应介质中的光致电子转移反应

基本信息

批准号：
08454230
负责人：
MIZUNO Kazuhiko
金额：
$ 4.03万
依托单位：
Osaka Prefecture University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1997
项目状态：
已结题

项目摘要

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.

对本课题进行了调查，得到以下结果： 1．在各种手性猝灭剂对 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辨别。猝灭速率根据猝灭剂的结构、给电子能力和手性而变化。最大的手性区别在于对映体对(+)-和(-)-N-(α-甲基苄基)-2,5-二甲基吡咯对1a的荧光猝灭。2．在由 1a 和芳香胺（例如二甲基苯胺 (2)）通过手性猝灭剂产生的发射激基复合物的荧光猝灭中也观察到手性辨别。 (+)-肉桂酸薄荷酯在苯中对1a/2和1b/2体系的激基复合物发射的荧光猝灭中的kqtau比显示最大值为1.08，并且随着溶剂极性的增加而减小。这些结果表明手性猝灭剂与手性激基复合物以对映选择性方式相互作用。 3．研究了手性敏化剂（例如带有薄荷基和胆固醇基团的 1,4-二氰基萘和 9,10-二氰基蒽）催化醇与芳基烯烃的光化学极性加成。甲醇与 2-胆固醇氧基甲基-1,4-二氰基萘敏化的 1,1-二苯基丙烯的反马尔可夫尼科夫加成显示出最大值，即 27% 对映体过量。4．呋喃和萘环1-位或2,3-位上具有手性烷氧基羰基的萘衍生物之间的分子间和分子内光环加成分别以非对映选择性方式生成(4+4)环加合物和笼状化合物。此外，研究表明产物的区域化学受激基复合物的偶极矩控制。