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首页> 外文期刊>Chemistry: A European journal >Synthesis of mono- and disubstituted porphyrins: A- and 5,10-A(2)-type systems
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Synthesis of mono- and disubstituted porphyrins: A- and 5,10-A(2)-type systems

机译：单取代和双取代的卟啉的合成：A和5,10-A（2）型系统

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摘要

General syntheses have been developed for meso-substituted porphyrins with one or two substituents in the 5,10-positions and no beta substituents. 5-Substituted porphyrins with only one meso substituent are easily prepared by an acid-catalyzed condensation of dipyrromethane, pyrrole-2-carbaldehyde. and an appropriate aldehyde using a "[2+1+1]" approach. Similarly, 5,10-disubstituted porphyrins are accessible by simple condensation of unsubstituted tripyrrane with pyrrole and various aldehydes using a "[3+1]" approach. The yields for these reactions are low to moderate and additional formation of either di- or mono-substituted porphyrins due to scrambling of the intermediates is observed. However, the reactions can be performed quite easily and the desired target compounds are easily removed due to large differences in solubility. A complementary and more selective synthesis involves the use of organolithium reagents for SNAr reactions. Reaction of in situ generated porphyrin (porphine) with 1.1-8 equivalents of RLi gave the monosubstituted porphyrins, while reaction with 3-6 equivalents of RLi gave the 5,10-disubstituted porphyrins in yields ranging from 43 to 90%. These hitherto almost inaccessible compounds complete the series of different homologues of A-, 5,15-A(2)-, 5,10-A(2)-, A(3)-, and A(4)-type porphyrin's and allow an investigation of the gradual influence of type, number, and regiochemical arrangement of substituents on the properties of meso-substituted porphyrins. They also present important starting materials for the synthesis of ABCD porphyrins and are potential synthons for supramolecular materials requiring specific substituent orientations.
机译：已经开发出对于在5,10位具有一个或两个取代基且没有β取代基的内消旋卟啉的一般合成方法。通过二吡咯甲烷，吡咯-2-甲醛的酸催化缩合，可以很容易地制备仅具有一个内消旋取代基的5-取代的卟啉。和适当的醛使用“ [2 + 1 + 1]”方法。类似地，通过使用“ [3 + 1]”方法将未取代的三吡喃与吡咯和各种醛进行简单缩合可得到5,10-二取代的卟啉。这些反应的产率低至中等，并且观察到由于中间体的加扰而另外形成的二取代或单取代的卟啉。然而，由于溶解度的巨大差异，反应可以非常容易地进行，并且所需的目标化合物易于除去。补充性和选择性更高的合成涉及将有机锂试剂用于SNAr反应。原位生成的卟啉（卟啉）与1.1-8当量的RLi反应生成单取代的卟啉，而与3-6当量的RLi反应则生成5,10-二取代的卟啉，产率为43％至90％。这些迄今几乎无法接近的化合物完成了A-，5,15-A（2）-，5,10-A（2）-，A（3）-和A（4）型卟啉和允许研究取代基的类型，数量和区域化学排列对介孔取代卟啉性质的逐渐影响。它们也为合成ABCD卟啉提供了重要的起始原料，并且是需要特定取代基取向的超分子材料的潜在合成子。

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