Synthesis of 2-Azaindolizines by Using an Iodine-Mediated Oxidative Desulfurization Promoted Cyclization of N-2-Pyridylmethyl Thioamides and an Investigation of Their Photophysical Properties
摘要:
Iodine-mediated, oxidative desulfurization promoted cyclization of N-2-pyridylmethyl thioamides serves as an efficient and versatile method for the preparation of 2-azaindolizines (imidazo[1,5-a]pyridines) and rare 2-azaindolizine sulfur-bridged dimers. The 2-azaindolizines prepared in this manner are readily converted to a variety of fluorescent compounds by using transition-metal-catalyzed cross-coupling reactions.
Copper-Catalyzed CH Bond Direct Chalcogenation of Aromatic Compounds Leading to Diaryl Sulfides, Selenides, and Diselenides by Using Elemental Sulfur and Selenium as Chalcogen Sources Under Oxidative Conditions
oxidation conditions. The use of a polar solvent was crucial for the reaction, and DMSO (dimethyl sulfoxide) in particular stimulated the reaction. The reaction could be applied to common aromaticcompounds, such as N‐methyl indole and dialkyl anilines. The reaction of indole proceeded at the nucleophilic C3 position rather than at the acidic C2 position. In addition, the reaction of dialkyl anilines
进行了铜盐催化的芳香族化合物与元素硫属元素的反应,并以分子氧作为氧化剂。在CuTC(铜(I)噻吩羧酸盐)存在下,3-取代的咪唑并[1,5- a ]吡啶与元素硫的反应以良好的定量收率得到了相应的双咪唑并吡啶基硫化物。即使在有氧氧化条件下,反应也进行。极性溶剂的使用对于反应至关重要,尤其是DMSO(二甲基亚砜)会促进反应。该反应可应用于常见的芳族化合物,例如N-甲基吲哚和二烷基苯胺。吲哚的反应在亲核的C3位置进行,而不是在酸性的C2位置进行。另外,二烷基苯胺的反应以邻位,对位进行。咪唑并吡啶与元素硒在相似条件下的反应得到相应的双咪唑并吡啶二硒化物和双咪唑并吡啶单硒化物。在相同条件下,未反应的咪唑并吡啶易于将得到的二硒化物转化为相应的单硒化物。该反应可用于双官能双咪唑并吡啶和元素硫的共聚,以定量收率得到低聚物。
Synthesis of 1,3-diarylated imidazo[1,5-a]pyridines with a combinatorial approach: metal-catalyzed cross-coupling reactions of 1-halo-3-arylimidazo[1,5-a]pyridines with arylmetal reagents
reagents led to 1,3-diarylated imidazo[1,5-a]pyridines in good to excellent yields. Suzuki–Miyaura cross-coupling of the 1-bromo-3-phenylimidazo[1,5-a]pyridine and p- or m-methoxycarbonylphenylboronic acids furnished the coupling product in respective yields of 91% and 61%. The obtained 1,3-diarylated imidazo[1,5-a]pyridines showed a wide variety of fluorescent emissions in a wavelength range of 449–533 nm
用碘,溴,N-氯代琥珀酰亚胺和1-氟-2,4,6-三甲基吡啶四氟硼酸盐作为卤化剂进行3-芳基咪唑并[1,5- a ]吡啶的卤化反应,得到选择性卤化的产物1-卤-3-芳基咪唑并[1,5- a ]吡啶的产率高至优异。所获得的1-碘-3-芳基咪唑并[1,5- a ]吡啶和芳基格氏试剂的Kumada-Tamao-Corriu交叉偶联导致1,3-二芳基化的咪唑并[1,5- a ]吡啶良好或优异。产量。1-溴-3-苯基咪唑并[1,5- a ]吡啶与p-或m的铃木-宫浦交叉偶联-甲氧基羰基苯基硼酸分别以91%和61%的产率提供了偶联产物。与单芳基化的相比,获得的1,3-二芳基化的咪唑并[1,5- a ]吡啶在449-533 nm的波长范围内具有多种荧光发射,并具有提高的量子产率。
Halogenated imidazo[1,5-a]pyridines: chemical structure and optical properties of a promising luminescent scaffold
作者:Giorgio Volpi、Claudio Garino、Emanuele Priola、Claudio Magistris、Michele R. Chierotti、Claudia Barolo
DOI:10.1016/j.dyepig.2019.107713
日期:2019.12
A series of halogenated imidazo[1,5-a]pyridines was prepared and their structural and optical properties investigated. The products were characterized by spectroscopic techniques and their optical properties discussed in relation to their chemical structure. We were able to triplicate the luminescence quantum yields (φ) in solution for three different imidazo[1,5-a]pyridine derivatives, depending on
制备了一系列卤代咪唑并[1,5- a ]吡啶,并对其结构和光学性质进行了研究。通过光谱技术表征了产物,并讨论了关于其化学结构的光学性质。我们能够一式三份的溶液中的发光量子产率(φ)为三个不同的咪唑并[1,5-一个]吡啶衍生物,这取决于取代基的性质卤素的咪唑并[1,5-一个]吡啶部分。通过单晶X射线衍射研究了卤素以及分子骨架的几何和化学特征对晶体堆积的影响。同时,通过固态NMR分析评估了可能存在的卤素键。
Cu(I)-Catalyzed Transannulation of <i>N</i>-Heteroaryl Aldehydes or Ketones with Alkylamines via C(sp<sup>3</sup>)–H Amination
A copper(I)-catalyzed direct transannulation of N-heteroaryl aldehydes or ketones with alkylamines via C-sp(3)-H amination has been achieved using molecular oxygen as a sole oxidant. N-Heteroarenes are employed as the amine source. This transformation provides a rapid and concise access to multifunctional imidazo[1,5-a]pyridines.