Transfer hydrogenation of pyridinium and quinolinium species using ethanol as a hydrogen source to access saturated N-heterocycles
作者:Suman Yadav、Dhananjay Chaudhary、Naveen Kumar Maurya、Dharmendra Kumar、Km Ishu、Malleswara Rao Kuram
DOI:10.1039/d2cc00241h
日期:——
Catalytic transfer hydrogenation (TH) for the reduction of heterocycles is an emerging strategy for accessing biologically active saturated N-heterocycles. Herein, we report a TH protocol that utilizes ethanol as a renewable hydrogen source and an Ir catalyst for the reduction of quinolines and pyridines. The reaction is promoted by simple amides as ligands.
用于还原杂环的催化转移氢化 (TH) 是获得具有生物活性的饱和 N-杂环的新兴策略。在此,我们报告了一种 TH 协议,该协议利用乙醇作为可再生氢源和 Ir 催化剂来还原喹啉和吡啶。该反应通过简单的酰胺作为配体来促进。
Non-thermal internal energy distribution of ions observed in an electrospray source interfaced with a sector mass spectrometer
The internalenergy distribution P(Eint) of ions emitted in an electrospray (ESI) source interfaced with a sector massspectrometer is evaluated by using the experimental survival yield (SY) method including the kinetic shift. This method is based on the relationship between the degree of fragmentation of an ion and its amount of internalenergy and uses benzylpyridinium cations due to their simple
‘One-pot’ Hammett plots: a general method for the rapid acquisition of relative rate data
作者:Hon Man Yau、Anna K. Croft、Jason B. Harper
DOI:10.1039/c2cc34074g
日期:——
A general âone-potâ method for determining relative rates of reaction in complex mixtures has been established using free energy relationships to demonstrate its utility. Competition experiments involving as many as seven species gave relative rate constants that are in good agreement to those obtained from individual kinetic analyses.
Bromide complexes of bismuth with 4-bromobenzyl-substituted cations of pyridinium family
作者:Igor D. Gorokh、Sergey A. Adonin、Andrey N. Usoltsev、Alexander S. Novikov、Denis G. Samsonenko、Sergey V. Zakharov、Maxim N. Sokolov、Vladimir P. Fedin
DOI:10.1016/j.molstruc.2019.126955
日期:2020.1
Abstract Two bromobismuthate (III) complexes containing 4-bromobenzyl-substituted pyridinium cations – (1-(4-BrBz)Py)3[Bi2Br9] (1) and (1-(4-BrBz)-2-MePy)3[BiBr6] (2) – were prepared by reactions of Bi2O3 and corresponding pyridinium bromides in HBr. In the structure of 1 there are weak contacts between the Br atoms of 1-(4-BrBz)Py+ and bromide ligands of [Bi2Br9]3-, while in the case of 2 such interactions
Copper-Catalyzed Oxidative [3 + 2] Cycloaddition of <i>N</i>-Alkyl Pyridinium Salts to Imidazo[1,2-<i>a</i>]pyridines
作者:Yuan Zhang、Weibin Fan、Yinghua Li、Deguang Huang
DOI:10.1021/acs.joc.3c00728
日期:2023.9.1
A copper-catalyzed reaction of pyridiniumsalts and trimethylsilyl cyanide (TMSCN) in the presence of diethyl phosphite is developed. This reaction, which allows the single-step construction of biologically important 2-cyanoimidazo[1,2-a]pyridine from readily available starting materials, is realized for the first time and is feasible at the gram scale. The scope of the protocol is demonstrated with
开发了在亚磷酸二乙酯存在下吡啶鎓盐和三甲基硅烷基氰化物 (TMSCN) 的铜催化反应。该反应首次实现了从容易获得的起始材料一步构建生物学上重要的2-氰基咪唑并[1,2- a ]吡啶的反应,并且在克级是可行的。该协议的范围通过 27 个示例进行了演示。在这一一锅法中可以实现连续的双氰化和环化。TMSCN 发挥双重作用,不仅作为“CN”源,而且作为咪唑并[1,2- a ]吡啶环化的偶联伙伴。