Azulichlorins and Benzocarbachlorins Derived Therefrom
Azulichlorins and Benzocarbachlorins Derived Therefrom
复制标题
天青二氯林和由其衍生的苯并卡巴二氯林
DOI：
10.1021/acs.joc.9b01578
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Lash, Timothy D.
中科院分区：
文献类型：
--
作者：
Noboa, Mario A.;AbuSalim, Deyaa I.;Lash, Timothy D.
酸催化的azulidipyrrane醛与二氢二吡咯甲醛的缩合提供了azulichlorins的第一个实例。这些大环产物以单质子化形式分离，并且游离碱被证明有些不稳定。一价阳离子是强向异性的，并且质子NMR光谱显示内部C-H在约100 ° C处。-2 ppm。添加TFA得到相关的dications，但这些表现出显着降低芳环电流。在二氯甲烷/甲醇中，三氯偶氮与叔丁基过氧化氢和KOH反应，得到苯并氨甲酰氯和两种相关的醛。苯并氨甲酰氯灵的紫外-可见光谱在414和430 nm处显示出分裂的Soret带，在684 nm处有强烈的类氯吸收。质子核磁共振谱表明氨甲酰氯是强芳香性的，内部的C-H在−4.64 ppm处被观察到。加入TFA后，C-质子化双阳离子的环电流显著增加。质子NMR谱、NICS计算和AICD图表明，该体系有利于通过稠合苯并单元的22π电子离域途径。添加三氟乙酸的benzocarbachlorin醛主要导致形成单价阳离子，和C-质子化的dications的产生不再是有利的，由于存在吸电子的甲酰基部分。
Acid-catalyzed condensation of azulidipyrrane aldehydes with a dihydrodipyrrin carbaldehyde afforded the first examples of azulichlorins. These macrocyclic products were isolated in a monoprotonated form, and the free bases proved to be somewhat unstable. The monocations were strongly diatropic, and proton NMR spectroscopy showed the internal C–H at ca. −2 ppm. Addition of TFA gave the related dications, but these exhibited significantly reduced aromatic ring currents. Reaction of an azulichlorin withtert-butyl hydroperoxide and KOH in dichloromethane/methanol gave a benzocarbachlorin and two related aldehydes. The UV–vis spectrum for the benzocarbachlorin showed a split Soret band at 414 and 430 nm, together with a strong chlorin-like absorption at 684 nm. The proton NMR spectrum indicated that the carbachlorin is strongly aromatic and the internal C–H was observed at −4.64 ppm. Addition of TFA afforded a C-protonated dication with a significantly increased diatropic ring current. The proton NMR spectrum, NICS calculations, and AICD plots indicated that the system favors a 22π electron delocalization pathway that runs through the fused benzo unit. Addition of TFA to the benzocarbachlorin aldehydes primarily led to the formation of monocations, and the generation of C-protonated dications was no longer favored due to the presence of electron-withdrawing formyl moieties.