Single Electron Transfer-Promoted Photocyclization Reactions of Linked Acceptor−Polydonor Systems: Effects of Chain Length and Type on the Efficiencies of Macrocyclic Ring-Forming Photoreactions of Tethered α-Silyl Ether Phthalimide Substrates
作者:Dae Won Cho、Jung Hei Choi、Sun Wha Oh、Chunsheng Quan、Ung Chan Yoon、Runtang Wang、Shaorong Yang、Patrick S. Mariano
DOI:10.1021/ja076846l
日期:2008.2.1
center to the terminal alpha-trimethylsilyl ether position. In addition, an inverse relationship was observed between the quantum yields of photocyclization reactions of the tethered phthalimides and naphthalimides and the length of the polyethylenoxy chain. Finally, the roles played by chain type and length in governing photoreaction efficiencies were investigated by using intramolecular competition
描述了一项调查结果,旨在获得有关控制单电子转移 (SET) 促进的连接受体-多供体系统的光环化反应效率的因素的信息。在这项工作中使用的一组基材包括 α-三甲基甲硅烷基醚封端、聚亚甲基和聚亚乙基氧基连接的邻苯二甲酰亚胺和 2,3-萘二甲酰亚胺。观察到聚氧乙烯连接的邻苯二甲酰亚胺和萘二甲酰亚胺的光环化反应以更高的化学产率和更大的量子效率发生,而不是含有几乎相等长度的聚亚甲基系链的类似物。这些发现表明,1、在光环化过程中作为关键中间体的 omega-两性离子双自由基在链中含有氧供体位点的物质中得到增强。研究结果表明,这些供体位点促进初始 SET 到受体激发态和随后的链内 SET,导致阳离子自由基中心迁移到末端 α-三甲基甲硅烷基醚位置。此外,在系留邻苯二甲酰亚胺和萘二甲酰亚胺的光环化反应的量子产率与聚氧乙烯链的长度之间观察到反比关系。最后,通过在聚氧乙烯和聚亚甲基双系邻苯二甲酰亚胺的光反应中使用
A Facile Approach to the Preparation of Bis-Crown Ethers Based on SET-Promoted Photomacrocyclization Reactions
作者:Nam Kyung Sung、Dae Won Cho、Jung Hei Choi、Kyung Wha Choi、Ung Chan Yoon、Hajime Maeda、Patrick S. Mariano
DOI:10.1021/jo701770x
日期:2007.11.1
[GRAPHICS]A novel methodology for the synthesis of bis-crown ethers has been developed. The preparative route takes advantage of an efficient single electron transfer promoted photomacrocyclization reaction of polyether branched bisphthalimides which contain a-trimethylsilylmethyl groups at terminal positions. The generality of the methodology was demonstrated by its application to the synthesis of symmetric and unsymmetric bis-crown ethers of various ring sizes. Finally, the metal cation binding and fluorescence emission properties of the bis-crowns, prepared by using the developed procedure, were briefly explored.
Yoon, Ung Chan; Oh, Sun Wha; Lee, Chan Woo, Heterocycles, 1995, vol. 41, # 12, p. 2665 - 2682
作者:Yoon, Ung Chan、Oh, Sun Wha、Lee, Chan Woo
DOI:——
日期:——
Photochemical Approach to the Preparation of Lariat Crown Ethers Containing Peptide Sidearms
作者:Dae-Won Cho、Chunsheng Quan、Hea-Jung Park、Ung-Chan Yoon、Patrick S. Mariano
DOI:10.5012/bkcs.2011.32.2.503
日期:2011.2.20
New types of lariat type crownethers containing peptide sidearms were prepared by using a novel strategy employing single electron transfer (SET)-induced photocyclization reactions of -silylether terminated phthalimides. Reactions of chiral substrates in this series produced diastereomeric mixtures of crownether products as a result of the formation of new stereogenic center generation in the photocyclization