Faiz Jonathan A, Spencer Neil, Pikramenou Zoe
School of Chemistry, The University of Birmingham, Edgbaston, B15 2TT, UK.
Org Biomol Chem. 2005 Dec 7;3(23):4239-45. doi: 10.1039/b508607h. Epub 2005 Oct 25.
A mono-6-O-propargyl permethylated beta-cyclodextrin, 3, has been prepared by two synthetic routes as a versatile building block for the construction of cyclodextrin dimers and trimers with a core junction which is potentially electron conducting. Glaser-Hay coupling of 3 gave beta-cyclodextrin dimer 6, and Pd(0)-catalysed coupling allowed the preparation of a cyclodextrin dimer with a 1,4-phenylene bridge, 7, and a cyclodextrin trimer based on a 1,3,5-trisubstituted benzene, 8. All compounds have been fully characterised, and in particular, detailed analysis by 2D NMR spectroscopic techniques has provided useful insight into the identities of the compounds. The detailed full characterisation of mono-3,6-anhydro-heptakis(2,3-O-methyl)-hexakis(6-O-methyl)-beta-cyclodextrin, 5, is also described. Product 5 is formed during the methylation of compound 3, and its formation was found to be sensitive to the reaction conditions. The absorption and fluorescence spectra of the phenylene-bridged dimer 7 and trimer 8 are also reported. They show different properties of the excited state based on the different electronic coupling imposed by the phenylene core.
一种单-6-O-炔丙基全甲基化的β-环糊精3，已通过两种合成路线制备出来，作为一种通用的结构单元，用于构建具有潜在电子传导性核心连接的环糊精二聚体和三聚体。3的Glaser-Hay偶联反应得到β-环糊精二聚体6，钯(0)催化的偶联反应使得能够制备具有1,4-亚苯基桥的环糊精二聚体7和基于1,3,5-三取代苯的环糊精三聚体8。所有化合物均已得到充分表征，特别是通过二维核磁共振光谱技术进行的详细分析为化合物的结构提供了有用的见解。还描述了单-3,6-脱水-七(2,3-O-甲基)-六(6-O-甲基)-β-环糊精5的详细全面表征。产物5在化合物3的甲基化过程中形成，发现其形成对反应条件敏感。还报道了亚苯基桥连二聚体7和三聚体8的吸收光谱和荧光光谱。基于亚苯基核心施加的不同电子耦合，它们显示出激发态的不同性质。
