Synthesis of indaphyrins: meso-tetraarylsecochlorin-based porphyrinoids containing direct o-phenyl-to-β-linkages
作者:Jason R. McCarthy、Michael A. Hyland、Christian Brückner
DOI:10.1039/b401629g
日期:——
The synthesis of indaphyrins, novel meso-tetraarylsecochlorin-derived chromophores incorporating o-phenyl-to-β-linkages, is described. Oxidative diol cleavage of meso-tetraaryl-2,3-dihydroxy-2,3-chlorins results in the formation of a secochlorin bisaldehyde. Depending on the reaction conditions during the ring cleavage reaction, one or two of the aldehyde groups react with the adjacent o-phenyl positions, leading to an intramolecular electrophilic aromatic substitution of the o-phenyl proton, and the establishment of a direct o-phenyl-to-β-linkage. The initially formed carbinol is spontaneously oxidized to the corresponding ketone. This modification forces the aryl groups into co-planarity with the macrocycle, allowing for interactions between the Ï-electrons of the aryl groups, the ketone linkage, and those of the chromophore, resulting in a significant electronic modulation of the porphyrinic Ï-system. The UV-vis spectroscopic properties of the free base, CuII, NiII, and ZnII indaphyrins are discussed.
本研究描述了吲达霉素的合成过程,吲达霉素是一种新型中-四芳基-secochlorin 衍生的发色团,含有邻苯基-δ-连接。中-四芳基-2,3-二羟基-2,3-氯素的氧化二醇裂解会形成仲氯素双醛。根据裂环反应过程中的反应条件,一个或两个醛基会与邻近的邻苯基位置发生反应,导致邻苯基质子发生分子内亲电芳香取代反应,并建立邻苯基与δ的直接连接。最初生成的甲醇会自发氧化成相应的酮。这种修饰迫使芳基与大环共面,使芳基的Ï电子、酮连接和发色团的Ï电子之间发生相互作用,从而对卟啉Ï系统产生显著的电子调节作用。本文讨论了游离碱、CuII、NiII 和 ZnII indaphyrins 的紫外-可见光谱特性。