Lash T D, Gandhi V
Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, USA.
J Org Chem. 2000 Nov 17;65(23):8020-6. doi: 10.1021/jo001216m.
Porphyrins with fused isoquinoline and quinoline units have been prepared by the "3 + 1" methodology. 5-Nitroisoquinoline and 6-nitroquinoline condensed with ethyl isocyanoacetate in the presence of a phosphazene base to give isoquino- and quinopyrroles, respectively. Ester saponification and decarboxylation with KOH in ethylene glycol at 190 degrees C gave the parent azatricycles, and these were further condensed with 2 equiv of an acetoxymethylpyrrole to give the corresponding tripyrranes protected at the terminal positions as their tert-butyl esters. In a one-pot procedure, the ester protective groups were cleaved with TFA, and following dilution with dichloromethane, "3 + 1" condensation with a pyrrole dialdehyde and dehydrogenation of the phlorin intermediate with DDQ gave the targeted azanaphthoporphyrins in excellent yields. Although the UV-vis spectra of these new porphyrin systems are unexceptional, they show promise for further functionalization and applications in the development of porphyrin arrays. In addition, a zinc chelate of the isoquinoporphyrin system shows a high degree of regioselective intermolecular interaction/aggregation in chloroform solution that may lead to selectivity in molecular recognition studies.
通过“3 + 1”方法制备了具有稠合异喹啉和喹啉单元的卟啉。5-硝基异喹啉和6-硝基喹啉在磷腈碱存在下与异氰基乙酸乙酯缩合，分别得到异喹啉基和喹啉基吡咯。在190℃下于乙二醇中用氢氧化钾进行酯皂化和脱羧反应，得到母体氮杂三环化合物，然后将这些化合物与2当量的乙酰氧基甲基吡咯进一步缩合，得到在末端位置以叔丁酯形式保护的相应三吡咯。在一锅法中，用三氟乙酸裂解酯保护基团，用二氯甲烷稀释后，与吡咯二醛进行“3 + 1”缩合，并使用2,3-二氯-5,6-二氰基-1,4-苯醌将卟吩中间体脱氢，以优异的产率得到目标氮杂萘卟啉。尽管这些新的卟啉体系的紫外-可见光谱并无异常，但它们在卟啉阵列的进一步功能化和应用方面显示出前景。此外，异喹啉卟啉体系的锌螯合物在氯仿溶液中表现出高度的区域选择性分子间相互作用/聚集，这可能导致分子识别研究中的选择性。
