Kröhnke condensation of several cycloimmonium salts with p-dimethylaminobenzaldhyde has been studied. X-Ray diffraction, IR and Raman spectra, 1H-and 13C-NMR and UV spectra of the products are discussed, being compared, when necessary, with the starting pyridinium salts. All compounds showed the Z configuration, corresponding to the more stable structure, except one, in which steric factors were predominant
A highly efficient method for the synthesis of 2-hydroxy-2,3-dihydrofuran derivatives from 1,4-enediones and phenacyl pyridinium halides via a domino reaction has been developed. This is a simple and beneficial strategy for the construction of 2-hydroxy-2,3-dihydrofuran compounds from readily available starting materials under mild conditions. Moreover, the application of this reaction provides a straightforward
Stereoselective Synthesis of Atropisomeric Bipyridine <i>N,N′</i>-Dioxides by Oxidative Coupling
作者:Yasuaki Fukazawa、Vladimir Yu. Vaganov、Sergei A. Shipilovskikh、Aleksandr E. Rubtsov、Andrei V. Malkov
DOI:10.1021/acs.orglett.9b01687
日期:2019.6.21
Bipyridine N,N′-dioxide is a structural fragment found in many bioactive compounds. Furthermore, chiral analogues secured their place as powerful Lewis base catalysts. The scope of the existing methods for the synthesis of atropisomeric bipyridine N,N′-dioxides is limited. Herein, we present a practical, highly chemo- and stereoselective method for oxidative dimerization of chiral pyridine N-oxides using
Direct synthesis of 3,5‐diaryl‐1,2,
<scp>4‐oxadiazoles</scp>
using 1‐(2‐oxo‐2‐arylethyl)pyridin‐1‐iums with benzamidines
作者:Yue Zhang、Chengjun Wu、Xinyi Wan、Cunde Wang
DOI:10.1002/jhet.4354
日期:2021.12
An efficient domino protocol for the synthesis of 1,2,4-oxadiazole derivatives from readily available 1-(2-oxo-2-arylethyl)pyridin-1-iums and amidine hydrochlorides was developed. In this practical approach, N-acyl amidine precursors were formed firstly via a simple nucleophilic substitution, without the purification of N-acylamidine intermediates, and the following intramolecularly dehydrative cyclization
开发了一种用于从容易获得的 1-(2-oxo-2-arylethyl)pyridin-1-iums 和脒盐酸盐合成 1,2,4-恶二唑衍生物的有效多米诺协议。在该实用的方法,Ñ酰基脒前体通过简单的亲核取代首先形成,未经纯化Ñ -acylamidine中间体和分子内下列脱水闭环中的我的存在下,得到1,2,4-恶二唑衍生物2 / K 2 CO 3 /DMSO 表现出优异的官能团耐受性并在简单的实验条件下进行。
Kröhnke pyridines: Rapid and facile access to Mcl-1 inhibitors
作者:Ivie L. Conlon、Daniel Van Eker、Sameh Abdelmalak、William A. Murphy、Hassan Bashir、Michael Sun、Jay Chauhan、Kristen M. Varney、Raquel Godoy-Ruiz、Paul T. Wilder、Steven Fletcher
DOI:10.1016/j.bmcl.2018.03.050
日期:2018.6
Accordingly, the development of Mcl-1 inhibitors largely focuses on synthetic BH3 mimicry. The condensation of α-pyridinium methyl ketone salts and α,β-unsaturatedcarbonylcompounds in the presence of a source of ammonia, or the Kröhnke pyridine synthesis, is a simple approach to afford highly functionalized pyridines. We adapted this chemistry to rapidly generate low-micromolar inhibitors of Mcl-1 wherein