Synthesis of Nitrogen-Containing Polyaromatics by Aza-Annulative π-Extension of Unfunctionalized Aromatics
Synthesis of Nitrogen-Containing Polyaromatics by Aza-Annulative π-Extension of Unfunctionalized Aromatics
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DOI：
10.1002/anie.201913394
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发表时间：
2020-03-02
影响因子：
16.6
通讯作者：
Itami, Kenichiro
中科院分区：
文献类型：
--
作者：
Kawahara, Kou P.;Matsuoka, Wataru;Itami, Kenichiro
含氮多环芳香族化合物（N-PAC）是材料科学中一类重要的化合物。这里报道的是一种新的氮杂环π延伸（aza-APEX）反应，该反应允许从容易获得的未官能化芳族化合物和亚胺酰氯中快速获得一系列N-PAC，产率为11-84%。在六氟磷酸银存在下，芳烃和亚氨基氯化物以区域选择性方式偶联。随后用对四氯苯醌进行氧化处理，得到结构多样的 N-PAC，但合成起来非常困难。 DFT计算表明，aza-APEX反应通过芳烃和原位生成的二芳基腈盐的形式[4+2]环加成进行，并具有相对较低的活化能的连续芳构化。还描述了 N-PAC 向氮掺杂纳米石墨烯的转化及其光物理性质。
Nitrogen-containing polycyclic aromatic compounds (N-PACs) are an important class of compounds in materials science. Reported here is a new aza-annulative pi-extension (aza-APEX) reaction that allows rapid access to a range of N-PACs in 11-84 % yields from readily available unfunctionalized aromatics and imidoyl chlorides. In the presence of silver hexafluorophosphate, arenes and imidoyl chlorides couple in a regioselective fashion. The follow-up oxidative treatment with p-chloranil affords structurally diverse N-PACs, which are very difficult to synthesize. DFT calculations reveal that the aza-APEX reaction proceeds through the formal [4+2] cycloaddition of an arene and an in situ generated diarylnitrilium salt, with sequential aromatizations having relatively low activation energies. Transformation of N-PACs into nitrogen-doped nanographenes and their photophysical properties are also described.