以meso-焦脱镁叶绿酸-a甲酯为起始原料,利用其二氢卟吩大环上的活性反应区域,选用不同的亲电试剂进行卤化和硝化反应,分别在20-meso-位上选择性地引进了氯、溴、碘和硝基;通过空气氧化和胺解等反应,对其五元E-环实施了结构改造,并在外接环上稠并了不同的含氮杂环,完成了13个未见报道的叶绿素类二氢卟吩衍生物的合成,其化学结构均经UV-Vis,IR,1H NMR及元素分析予以证实,同时讨论了meso-焦脱镁叶绿酸-a的化学反应机理和相应的光谱性质.
meso-Pyropheophorbide-a methyl ester was used as a starting material, and the halogenation and nitration were carried out with different electrophilic reagents making use of active regions in chlorin macrocycle selectively to introduce chlorine, bromine, iodine and nitryl group at 20-meso-position, respectively. The reconstructions for five-membered exocyclic E-ring by allomerization and aminolysis were completed to fuse different azo-heterocycle with the exocyclic ring. The synthesis of 13 unreported chlorins related to chlorophyll was accomplished and their chemical structures were characterized by elemental analysis, UV-Vis, IR and 1H NMR spectra. The reaction mechanisms of meso-pyropheophorbide-a and corresponding spectral properties were discussed.