含非对称苝二酰亚胺侧链多肽的合成

Synthesis of polypeptides with asymmetric perylene diimide side chains

苝二酰亚胺及其衍生物因具有独特的光物理和电化学性质而备受关注。为了获得具有新颖光物理性质的苝二酰亚胺材料,对其结构进行了修饰。以3,4,9,10-苝四羧酸二酐为起始原料,分步与环己胺和L-Ala-D-Leu-(N-Me)-Ala-D-Leu-Ally四肽进行氨解反应,用于合成不对称的苝二酰亚胺侧链多肽。考察了物料比、溶剂、催化剂等因素对反应的影响,确定了较优的反应条件。结果表明:当物料比n(苝酐)∶n(环己胺)=1∶6、乙醇/水为溶剂(V(乙醇)∶V(水)=4∶1)、于70℃反应6h,可得到中间产物N-环己基-3,4,9,10-苝四羧酸-3,4-酸酐-9,10-酰亚胺;后者再与LAla-D-Leu-(N-Me)-Ala-D-Leu-Ally链状四肽在咪唑中混合,以4-二甲氨基吡啶(以下简称DMAP)为催化剂,于120℃反应4h,可得到目标化合物N-环己基-N’-(L-Ala-D-Leu-(N-Me)-Ala-D-Leu-Ally)-3,4,9,10-苝四羧酸二酰亚胺,总收率为32.6%;得到的产物通过ESI-MS和1 HNHR进行了结构表征。该合成方法反应条件温和,操作简便,为制备非对称结构的苝二酰亚胺类化合物提供了一条便捷途径。

Perylenetetracarboxylic diimides(PDI)and their derivatives have been paid more attention due to their special photophysical and electrochemical properties.The modification on molecular structure of PDI aimed at changing the photophysical properties is one of an important means to obtain functional materials of PDI.An asymmetric PDI containing polypeptide chain at one imide nitrogen is synthesized by stepwise aminolysis reaction of 3,4,9,10-perylenetetracarboxylic dianhydride.The influence of reactions on yield is then inquired.The optimal reaction condition are determined as follows:molar ratio of PDI to cyclohexylamine,1∶6;the solvent volume ratio of ethanol to water,4∶1;reaction temprature and time,70℃and 6 h,the intermediate N-cyclohexyl-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide.In the presence of the catalyst DMAP,this intermediate undergoing aminolysis reaction with L-Ala-D-Leu-(N-Me)-Ala-D-Leu-Ally affords polypeptides with asymmetric PDI in imidazole for 4 h at 120℃,and the tatal yield is above 32.6%.The product structure is characterized by ESI-MS and 1H-NHR.The process is simple and mild conditions,which provides a convenient synthetic route for the preparation of asymmetric PDI compounds.