Asymmetric Photoreactions Using Microscopic Spaces

利用微观空间的不对称光反应

基本信息

批准号：
15350026
负责人：
MIZUNO Kazuhiko
金额：
$ 7.87万
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：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

Photochemical reactions using microscopic spaces were investigated to develop highly efficient and stereoselective photoreactions. The following results were obtained.(1)Control of intramolecular photocycloaddition of 1-cyanonaphthalene derivatives was studied in microreactors. By using the microreactors and flow system, both the efficiency and regioselectivity in the intramolecular photocycloaddition increased compared with those under batch conditions. An increase of efficiency can be attributed to thorough absorption of light in the thin ditch. Highly regioselective photoreaction was explained by flowing out of the initial product.(2)Asymmetric induction in photochemical reactions was investigated using chirally modified zeolites. Enantiomeric excesses (ee) was dependent on the structures of chiral materials adsorbed in zeolite cavity, SiO_2 / Al_2O_3 ratio, alkali metal cations in zeolites, molar ratio of substrates and chiral sources, and conversion of the reaction.(3)Stereocontro … More l in Photoalkylation and photoreduction of electron-deficient alkenes by allylic silanes was examined. Diastereomeric excesses (de) of products changed depending on the structures and stoichiometry of the added carboxylic acids. High diastereoselectivity can be attained when equimolar carboxylic acids bearing bulky substituents or hydroxy group at β-position were added.(4)Oxidative photodimerization of conjugated dienes proceeded in the presence of catalytic amount of 9-cyanophenanthrene to give nucleophile-incorporated photodimers of dienes in high yields. When chiral compounds were used as dienes or proton donors, enantioselective formation of 9-cyano-9,10-dihydrophenanthrene was observed.(5)Hydrogen bonding was effective for stereoselective photoreactions. Highly diastereoselective photocycloadditions of vinyl ethers and furan derivatives to electron-deficient naphthalene derivatives occurred to give (2+2) and caged cycloadducts via intermolecular hydrogen bonding in the ground states. Less

研究了利用微观空间的光化学反应，以开发高效、立体选择性的光反应。(1)利用微反应器和流动系统研究了1-氰基萘衍生物的分子内光环加成反应。与批量条件下相比，分子内光环加成的区域选择性有所提高，效率的提高可归因于细沟中光的彻底吸收。初始产物的流出解释了光反应的高度区域选择性。(2)利用手性改性沸石研究了光化学反应中的不对称诱导，其依赖于吸附在沸石空腔中的手性材料的结构、SiO_2/Al_2O_3比。，沸石中的碱金属阳离子，底物和手性源的摩尔比，以及转化率(3)通过烯丙基硅烷对缺电子烯烃进行光烷基化和光还原，研究了根据所添加的羧酸的结构和化学计量而改变的产物的非对映异构体过量(de)，可以获得高非对映选择性。添加等摩尔的β位带有大量取代基或羟基的羧酸。(4)氧化共轭二烯的光二聚反应在催化量的 9-氰基菲存在下进行，以高产率产生亲核试剂掺入的二烯光二聚体。当使用手性化合物作为二烯或质子供体时，对映选择性形成 9-氰基-9,10-二氢菲。 (5)氢键对于立体选择性光反应是有效的。乙烯基醚和呋喃衍生物与缺电子萘衍生物发生高度非对映选择性光环加成，通过基态分子间氢键生成 (2+2) 和笼状环加合物。