Pizzoli Francesco, Mita Alessandro, Caroleo Fabrizio, Nardis Sara, Calice Umberto, Caporale Marilena, Belviso Sandra, Superchi Stefano, Marconi Alessia, Calvaresi Matteo, Capolungo Chiara, Prodi Luca, Smith Kevin M, Fronczek Frank R, Paolesse Roberto
Department of Chemical Science and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica, 00133, Rome, Italy.
Department of Sciences, Università della Basilicata, Viale dell'Ateneo Lucano, 10, 85100, Potenza, Italy.
Chemistry. 2023 Nov 16;29(64):e202302517. doi: 10.1002/chem.202302517. Epub 2023 Oct 20.
Alkylation of one of the inner-core nitrogen atoms is one possible approach to obtain dianionic corrole ligands, suitable for the coordination of divalent metal ions, such as Pd . Inner-core N-methylation can be obtained by treating the corrole with CH I, but the reaction conditions should be optimized to limit the formation of the dimethylated derivative. Two regioisomers, the N-21 and the N-22 methyl derivatives are obtained from the reaction, with the first product achieved in a higher amount. Structural characterization of the reaction products evidenced the distortion induced by the introduction of the methyl groups; the N-methylcorroles are chiral compounds, and the enantiomers were separated by chromatography, with their absolute configuration assigned by ECD computation. Palladium insertion was achieved in the case of monosubstituted corroles, but not with the dimethylated macrocycle; X-ray characterization of the complexes showed the distortion of the macrocycles. The Pd complexes do not show luminescence emission, but are able to produce singlet oxygen upon irradiation. The Pd complexes were also inserted in human serum albumin (HSA) and dispersed in water; in this case, the protein protects the corroles from photobleaching, and a switch from the type II to the type I mechanism in reactive oxygen species (ROS) production is observed.
使内芯氮原子之一烷基化是获得适合与二价金属离子（如钯）配位的双阴离子卟吩配体的一种可能方法。通过用CH₃I处理卟吩可实现内芯N-甲基化，但应优化反应条件以限制二甲基化衍生物的形成。该反应可得到两种区域异构体，即N-21和N-22甲基衍生物，其中第一种产物的产量更高。反应产物的结构表征证明了甲基引入所引起的扭曲；N-甲基卟吩是手性化合物，对映体通过色谱法分离，其绝对构型通过ECD计算确定。在单取代卟吩的情况下实现了钯的插入，但二甲基化大环则未实现；配合物的X射线表征显示了大环的扭曲。钯配合物不显示发光发射，但在光照下能够产生单线态氧。钯配合物也被插入人血清白蛋白（HSA）并分散在水中；在这种情况下，蛋白质可保护卟吩不发生光漂白，并且观察到活性氧（ROS）产生机制从II型转变为I型。
