The Cu-catalyzed regioselective synthesis of phenazine N-oxides was realized from benzoxadiazoles and diaryliodonium salts. The process was initiated by the electrophilic arylation of benzoxadiazoles with diaryliodonium salts and followed by benzocyclization reactions. The further reduction of N-oxides in situ to phenazine scaffolds and deviation to organic fluorescent materials were readily accomplished
Cu-Catalyzed Cascade Reaction of Isoxazoles with Diaryliodonium Salts for the Synthesis of Acridines
作者:Shangrong Zhu、Xuechen Lu、Qiuneng Xu、Jian Li、Shenghu Yan
DOI:10.2174/1570178617666200225125427
日期:2020.12.8
A straightforward and efficient synthesis of acridinederivatives via a copper-catalyzed cascade reaction among isoxazoles and diaryliodoniumsalts is achieved. Various mono-, multi-substituted and 9-substituted acridinederivatives could be obtained in moderate to good yields. The process has gone through tandem double arylation and Friedel-Craftsreactions.
Radical and Ionic Mechanisms in Rearrangements of o-Tolyl Aryl Ethers and Amines Initiated by the Grubbs–Stoltz Reagent, Et3SiH/KOtBu
作者:Krystian Kolodziejczak、Alexander J. Stewart、Tell Tuttle、John A. Murphy
DOI:10.3390/molecules26226879
日期:——
investigation of the rearrangements of the aryl tolyl ethers now instead supports an anionic Truce–Smiles rearrangement, where the initial benzyl anion can be formed by either of two pathways: (i) direct deprotonation of the tolyl methyl group under basic conditions or (ii) electron transfer to an initially formed benzyl radical. By contrast, the rearrangements of o-tolyl aryl amines depend on the
最近宣布了使用 Grubbs-Stoltz 试剂(Et 3 SiH + KO t Bu)重排邻甲苯基芳基醚、胺和硫化物,其中醚转化为邻羟基二芳基甲烷,而(o-tol)(Ar)NH 胺转化为二氢吖啶。根据该试剂系统中三乙基甲硅烷基自由基的先前证据,提出了自由基机制。对芳基甲苯基醚重排的详细计算研究现在支持阴离子休战-微笑重排,其中初始苄基阴离子可以通过两种途径之一形成:(i)在碱性条件下甲苯基甲基的直接去质子化或(ii) 电子转移到最初形成的苄基。相比之下,o-的重排甲苯基芳基胺取决于胺的性质。仲胺经历 NH 的去质子化,然后发生自由基重排,形成二氢吖啶,而叔胺通过自由基和/或阴离子途径形成二氢吖啶和二芳基甲烷。总的来说,这项研究强调了由 Et 3 SiH/KO t Bu 系统形成的反应中间体之间的竞争。
Facile Synthesis of Unsymmetrical Acridines and Phenazines by a Rh(III)-Catalyzed Amination/Cyclization/Aromatization Cascade
作者:Yajing Lian、Joshua R. Hummel、Robert G. Bergman、Jonathan A. Ellman
DOI:10.1021/ja406131a
日期:2013.8.28
annulations of aromatic azides with aromatic imines and azobenzenes to give acridines and phenazines, respectively. These transformations proceed through a cascade process of Rh(III)-catalyzed amination followed by intramolecular electrophilic aromatic substitution and aromatization. Acridines can be directly prepared from aromatic aldehydes by in situ imineformation using catalytic benzylamine.