焦脱镁叶绿酸的区域和立体选择性的芳(芳酰)亚甲基化及其叶绿素类二氢卟吩衍生物的合成

Regio-and Stereoselective Aryl(aroyl)methylenenation of Pyropheophorbide and Syntheses of Chlorophyllous Chlorin Derivatives

以焦脱镁叶绿酸-a甲酯为起始原料,利用其外接环酮的空气氧化反应,在大环色基N^(21)-N^(23)轴的水溶性端向的不同位置上构建了甲酰基和邻位二酮结构.通过交叉羟醛缩合反应,在焦脱镁叶绿酸的外接环和12-位上区域和立体选择性地完成了芳(芳酰)亚甲基化,合成出一系列未见报道的具有芳(芳酰)烯酮结构单元的叶绿素类二氢卟吩衍生物,同时,讨论了芳(芳酰)亚甲基化二氢卟吩的形成机理、立体异构以及紫外-可见光谱性质.所有新合成化合物的结构均经UV-Vis、^(1)H NMR、MS以及元素分析予以证实.

Using the pyropheophorbide-a methyl ester as the starting material,the formyl group and α-diketone moiety were introduced into the water-soluble end of the N^(21)-N^(23) axis of the macrocyclic chromophore at different positions by the allomerization on the exocyclic ring ketone.Based on the cross-aldol condensation,the regio-and stereoselective aryl(aroyl)-methylenations of pyropheophorbide-a were accomplished on the exocyclic ring and at C12-position.A series of unreported chlorin derivatives that contain the aryl(aroyl)ketene unit were synthesized.In addition,the formation mechanism,stereoisomerism and the optical properties of the aryl(aroyl)methylenated products were discussed.The chemical structures of all newly synthesized compounds were characterized by elemental analysis,MS,UV-Vis and 1H NMR spectra.