3-Cyclobutenyl-1,2-dione-substituted porphyrins. A general and efficient entry to porphyrin-quinone and quinone-porphyrin-quinone architectures.
3-Cyclobutenyl-1,2-dione-substituted porphyrins. A general and efficient entry to porphyrin-quinone and quinone-porphyrin-quinone architectures.
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DOI：
10.1021/jo9912799
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发表时间：
2000-02
期刊：
影响因子：
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通讯作者：
X. Shi;S. R. Amin;L. S. Liebeskind
中科院分区：
文献类型：
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作者：
X. Shi;S. R. Amin;L. S. Liebeskind
通过在一个或两个不相邻的中间位置上含有3-环丁烯基-1,2-二酮和3-（1-乙烯基）环丁烯基-1,2-二酮取代基的卟啉中间体，开发了一种新的高效的中间连接卟啉-醌二联体和醌-卟啉-醌三联体的合成方法。游离基卟啉- 5-溴-10,20-二苯基卟啉和5,15-二溴-10,20-二苯基卟啉与3-异丙氧基-2-三正丁基-环丁烯-1,2-二酮通过钯催化的简单的Stille偶联反应，得到相应的单和双（3-环丁基-1,2-二酮）取代卟啉，产率高。相比之下，锌溴卟啉与相同的锡试剂反应缓慢，并形成副产物。游离基溴卟啉也与三正丁基乙烯基锡偶联，得到了产率很高的乙烯基卟啉。5,15-二苯基-10-乙烯基卟啉转化为反式溴基卟啉，与3-异丙氧基-2-三-正丁基丁基环丁烯-1,2-二酮进行简单的Stille偶联，得到3-环丁基-1,2-二酮取代的乙烯基卟啉。用x射线晶体学测定了5,15-二（3-环丁基-1,2-二酮）-10,20-二苯基卟啉（zn）的分子结构。虽然数据显示环丁烯二酮和卟啉环之间存在较大的二面角（57°），但单-和双（3-环丁烯基-1,2-二酮）取代卟啉的紫外-可见光谱均显示B-和q -波段红移，表明溶液中卟啉和环丁烯二酮发色团之间存在强电子耦合。在环丁烯二酮和卟啉环之间引入双键导致与非葡萄系相比，B和q带都发生了显著的红移。所有的卟啉环丁烯二酮都用锌金属化，然后利用已建立的环丁烯二酮化学，用芳基锂和乙烯基格氏试剂以优异的收率转化为各种卟啉醌。从单（3-环丁基-1,2-二酮）取代卟啉7，可以很容易地合成多种直接连接的单醌-卟啉二偶体。通过溴化和钯催化的交叉偶联反应，可以在7的自由介位上引入取代基，并以此为原料制备卟啉单醌类化合物。葡萄状的方基卟啉与苯基锂反应，经过热重排和氧化，转化为双键连接的卟啉醌。5,15-二（3-环丁基-1,2-二酮）-10,20-二苯基卟啉（zn）由于卟啉和醌之间的C-C键周围的旋转受阻，得到了一对稳定的、可分离的、热可互换的卟啉-醌的反旋异构体。用x射线晶体学测定了其中一种atropisomer的结构。
A new and efficient synthesis of meso-linked porphyrin-quinone dyads and quinone-porphyrin-quinone triads has been developed via the intermediacy of porphyrins bearing 3-cyclobutenyl-1,2-dione and 3-(1-ethenyl)cyclobutenyl-1,2-dione substituents at one or two nonadjacent meso-positions. The free-base porphyrins 5-bromo-10,20-diphenylporphyrin and 5,15-dibromo-10,20-diphenylporphyrin undergo facile palladium-catalyzed Stille coupling with 3-isopropoxy-2-tri-n-butylstannyl-cyclobutene-1,2-dione to produce the corresponding mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins in good yields. In contrast, the zinc bromoporphyrins reacted with the same tin reagent only slowly and with the formation of side products. The free-base bromoporphyrins also were coupled with tri-n-butylvinyltin to afford vinylporphyrins in very good yields. 5,15-Diphenyl-10-vinylporphyrin was converted into trans-bromovinylporphyrin, which underwent facile Stille coupling with 3-isopropoxy-2-tri-n-butylstannylcyclobutene-1,2-dione to afford the vinylogous 3-cyclobutenyl-1,2-dione-substituted porphyrin. The molecular structure of 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n) was determined by X-ray crystallography. Although the data revealed a fairly large dihedral angle between the cyclobutenedione and the porphyrin rings (57 degrees), the UV-vis spectra of both the mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins showed B- and Q-band red shifts indicative of strong electronic coupling between the porphyrin and cyclobutenedione chromophores in solution. Introduction of a double bond between the cyclobutenedione and porphyrin rings resulted in a significant red shift of both the B- and Q-bands compared to those of the nonvinylogous system. All porphyrinic cyclobutenediones were metalated with zinc and then, using established cyclobutenedione chemistry, converted into a variety of porphyrin-quinones in excellent yields with aryllithium and vinylic Grignard reagents. From the mono(3-cyclobutenyl-1,2-dione)-substituted porphyrin, 7, a variety of directly linked monoquinone-porphyrin dyads were easily synthesized. Substituents could also be introduced at the free meso-position of 7 by bromination followed by palladium-catalyzed cross-coupling reactions, and additional porphyrinic monoquinones were then prepared from these starting materials. The vinylogous squarylporphyrin was converted into a double bond linked porphyrin-quinone via reaction with phenyllithium followed by thermal rearrangement and oxidation. As a result of the hindered rotation around the C-C bond between the porphyrin and the quinone, pairs of stable, separable, and thermally interconvertable atropisomers of porphyrin-quinones were obtained from 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n). The structure of one of the atropisomers was determined by X-ray crystallography.