Investigation of the Scope of Heterogeneous and Homogeneous Procedures for Preparing Magnesium Chelates of Porphyrins, Hydroporphyrins, and Phthalocyanines.
Investigation of the Scope of Heterogeneous and Homogeneous Procedures for Preparing Magnesium Chelates of Porphyrins, Hydroporphyrins, and Phthalocyanines.
复制标题
研究制备卟啉、氢卟啉和酞菁镁螯合物的多相和均相程序的范围。
DOI：
10.1021/ic960812p
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发表时间：
1996
影响因子：
4.6
通讯作者：
J. Lindsey
中科院分区：
文献类型：
--
作者：
D. O’Shea;Mark A Miller;Hiroko Matsueda;J. Lindsey
本文提出了一种在室温下均相条件下，用稳定的MgI(2)和N，N-二异丙基乙胺的乙醚溶液使卟啉化合物金属化的简单方法。以前开发的一种多相程序在室温下在非配位溶剂中使用卤化镁和非亲核胺的混合物。对一系列19种卟啉化合物，包括合成的卟啉、合成的或天然存在的氯，以及有机可溶的酞菁，研究了异相和均相镁离子插入过程的范围。与配体的碱度相平行，系列的酞菁类化合物中镁的插入率增加。虽然酞菁镁的核尺寸最小，但在酸诱导的脱金属反应中，酞菁镁的稳定性远高于卟啉镁。非均相方法广泛适用于卟啉、氯化和酞菁。均相方法通常比多相方法慢，尽管这两种方法都提供了大多数卟啉的快速金属化，包括缺电子的、外围配位的或面阻碍的中位取代的四芳基卟啉，以及β取代的八乙基卟啉。在均相但不均相的条件下，e(6)三甲酯和焦脱镁叶绿酸a甲酯被干净地金属化，而脱镁叶绿素a两种方法都失败了。均相方法对于酞菁完全失败了。镁化学中已经发展了几种方法来加强这些过程，包括温和地合成四苯氯，以及基于选择性地形成镁螯合物来简化分离卟啉、氯和细菌氯。总而言之，这些方法应该扩大基于卟啉类化合物的镁螯合物的模型体系的范围。
A simple method has been developed for metalation of porphyrinic compounds under homogeneous conditions at room temperature using a stable ethereal solution of MgI(2) and N,N-diisopropylethylamine. A previously developed heterogeneous procedure employs a mixture of a magnesium halide and a nonnucleophilic amine in a noncoordinating solvent at room temperature. The scope of the heterogeneous and homogeneous magnesium insertion procedures has been investigated across a family of 19 porphyrinic compounds, including synthetic porphyrins, synthetic or naturally occurring chlorins, and organic-soluble phthalocyanines. The rate of magnesium insertion increased in the series phthalocyanines < chlorins < porphyrins, which parallels the basicity of the ligands. Though phthalocyanines have the smallest core size, the magnesium phthalocyanines were far more stable than magnesium porphyrins to acid-induced demetalation. The heterogeneous method is broadly applicable to porphyrins, chlorins, and phthalocyanines. The homogeneous method is generally slower than the heterogeneous method, though both afford rapid metalation of most porphyrins, including electron-deficient, peripherally coordinating, or facially encumbered meso-substituted tetraarylporphyrins, and the beta-substituted octaethylporphyrin. Chlorin e(6) trimethyl ester and methyl pyropheophorbide a were metalated cleanly under homogeneous but not heterogeneous conditions, while pheophytin a failed with both methods. The homogeneous method failed altogether with phthalocyanines. Several methods in magnesium chemistry have been developed that augment these procedures, including a mild synthesis of tetraphenylchlorin and a streamlined separation of porphyrin, chlorin, and bacteriochlorins based on selective formation of the magnesium chelates. Collectively, these methods should broaden the scope of model systems based on magnesium chelates of porphyrinic compounds.