A new facile, efficient synthesis and structure peculiarity of quinoxaline derivatives with two benzimidazole fragments
作者:Vakhid A. Mamedov、Nataliya A. Zhukova、Victor V. Syakaev、Aidar T. Gubaidullin、Tat'yana N. Beschastnova、Dil'bar I. Adgamova、Aida I. Samigullina、Shamil K. Latypov
DOI:10.1016/j.tet.2012.10.045
日期:2013.1
A highly efficient and versatile method for the synthesis of quinoxalinederivatives with two benzimidazole fragments have been developed on the basis of the ring contraction of 3-(benzimidazo-2-yl)quinoxalin-2(1H)-one with 1,2-diaminobenzene and its various types of substituted and condensed derivatives. Owing to the inter- and intramolecular processes, involving self association, proton exchange
基于3-(苯并咪唑-2-基)喹喔啉-2(1 H)-与1,2-的环收缩,已开发出一种高效且通用的具有两个苯并咪唑片段的喹喔啉衍生物的合成方法。二氨基苯及其各种类型的取代和稠合衍生物。由于分子间和分子内过程,涉及桥联和相邻碳原子的大多数双-苯并咪唑基喹喔啉信号的几种形式之间的自缔合,质子交换,构象和/或互变异构交换,且NMR光谱中的苯并咪唑片段变宽。苯并咪唑片段与分子的喹喔啉核心之间的共轭作用比喹喔啉衍生物(10c)与其噻二唑[ f ]-(17)和吡咯并[ a ]-(19)环化了衍生物,导致整个分子的平面度更大。
Synthesis of α-heterosubstituted ketones through sulfur mediated difunctionalization of internal alkynes
作者:Zhong Zhang、Yuzheng Luo、Hongguang Du、Jiaxi Xu、Pingfan Li
DOI:10.1039/c9sc00568d
日期:——
Synthesis of α-heterosubstituted ketones was achieved through sulfur mediated difunctionalization of internal alkynes in one pot. The reaction design involves: phenyl substituted internal alkyne attacking triflic anhydride activated diphenyl sulfoxide to give a sulfonium vinyl triflate intermediate, hydrolysis to give an α-sulfonium ketone, and then substitution with various nucleophiles. This method
Metal free synthesis of quinoxalines from alkynes via a cascade process using TsNBr2
作者:Debojit Hazarika、Prodeep Phukan
DOI:10.1016/j.tet.2017.01.056
日期:2017.3
protocol for the synthesis of quinoxalinesfrom alkynes has been developed. The reaction was carried out by treating alkynes with TsNBr2 in presence of O-phenylenediamines in a mixture of acetonitrile and water (9:1). This one-pot reaction proceeds via an oxidative transformation of alkynes to α,α-dibromoketones in presence of TsNBr2 and eventually to quinoxalines in presence of 1,2-diamines in a cascade
Highly efficient vinylaromatics generation via iron-catalyzed sp3 C–H bond functionalization CDC reaction: a novel approach to preparing substituted benzo[α]phenazines
An iron-catalyzed benzylic vinylation was developed to transfer the carbon atom in the N,N-dimethyl moiety of N,N-dimethylacetamide (or N,N-dimethylformamide) to 2-methyl azaarenes to generate 2-vinyl azaarenes.
Both elementaliodine and diphenyldiselenides, in the presence of [bis(trifluoroacetoxy)iodo]benzene (PIFA), promote the transformation of internal alkynes into the corresponding 1,2-diketones. The reactions carried out in the presence of iodine unfortunately did not proceed with complete conversion of the starting alkynes. On the other hand, diphenyldiselenide was more efficient and gave satisfactory