这项工作展示了通过可见光驱动的自由基-极性交叉环化策略合成各种全氟烷基杂环。在此过程中,单电子还原/ SN V型/环化序列遵循重氮酯的自由基加成反应,这与目前重氮酯作为自由基前体/受体的作用不同。这种转化表现出优异的官能团相容性,并允许用重氮酯修饰许多生物活性分子。这种反应可能代表了重氮化合物光化学转化的一种新方法。
Design, synthesis and biological evaluation of new rhodacyanine analogues as potential antitumor agents
作者:Yang Xiong Li、Xin Zhai、Wei Ke Liao、Wu Fu Zhu、Ying He、Ping Gong
DOI:10.1016/j.cclet.2012.01.015
日期:2012.4
attempt to develop potent antitumoragents, new rhodacyanine analogues containing the pyridinium ring ( 5a – 5h ), the isoquinolinium ring ( 6a – 6c ) and the quinolinium ring ( 7a – 7e ) linked to the rhodanine ring via N–N covalent bond were designed, synthesized and evaluated for antitumor activity against human lung cancer cell line (H460) by MTT assay in vitro . Most of the tested compounds showed enhanced
[3+2] Cycloaddition of N-Aminopyridines and Perfluoroalkynylphosphonates: Facile Synthesis of Perfluoroalkylated Pyrazolo[1,5-a]pyridines Containing a Phosphonate Moiety
3-Zwitterions generated from N-aminopyridines in the presence of base are trapped by perfluoroalkynylphosphonates to yield a variety of perfluoroalkylated pyrazolo[1,5-a]pyridine derivatives bearing a phosphonate group. The salient features of these [3+2] cycloadditions include operational simplicity, good tolerance of functional groups, and good to excellent yields at room temperature. 1,3-Zwitterions generated
§对这项工作有同等贡献。 抽象的 由N-氨基吡啶在碱存在下产生的1,3-两性离子被全氟炔基膦酸酯捕获,得到各种带有膦酸酯基团的全氟烷基化吡唑并[1,5- a ]吡啶衍生物。这些[3 + 2]环加成反应的显着特征包括操作简便,对官能团的良好耐受性以及在室温下良好至优异的收率。 由N-氨基吡啶在碱存在下产生的1,3-两性离子被全氟炔基膦酸酯捕获,得到各种带有膦酸酯基团的全氟烷基化吡唑并[1,5- a ]吡啶衍生物。这些[3 + 2]环加成反应的显着特征包括操作简便,对官能团的良好耐受性以及在室温下良好至优异的收率。
A convenient synthesis of polyfluoroalkyl-substituted pyrazolo[1,5-a] pyridine, pyrrolo[1,2-b]pyridazine and indolizine derivatives
作者:Xue-chun Zhang、Wei-yuan Huang
DOI:10.1016/s0022-1139(97)00118-8
日期:1998.1
(1b) or N-amino-isoquinolinium iodide (1c), N-phenacylpyridazinium (4), N-phenacylpyridinium (6a–c), and N-phenacylisoquinolinium (6d) bromides in DMF to give poly(per)fluoroalkyl-substituted pyrazolo[1,5-a] pyridine (3), pyrrolo[l,2-a]pyridazine (5) and indolizine (7 and 8) derivatives, respectively.
Preparation of New Nitrogen-Bridged Heterocycles. 42. Synthesis and the Reaction of Pyridinium<i>N</i>-Ylides Using Bifunctional Ethyl Thiocyanatoacetates
作者:Akikazu Kakehi、Suketaka Ito、Yasunobu Hashimoto
DOI:10.1246/bcsj.69.1769
日期:1996.6
cycloadditions of somepyridinium (unsymmetrically substituted cyanomethylide)s with dimethyl acetylenedicarboxylate (DMAD) in various solvents afforded only dimethyl 3-cyanoindolizine-1,2-dicarboxylate, except a few examples. On the other hand, the treatment of pyridinium (thiocyanatoaceto)- or (2-thiocyanatopropiono)amidates with a strong base, such as potassium t-butoxide, gave new bicyclic mesoionic compounds
Preparation of New Nitrogen-bridged Heterocycles. 11. A New Synthetic Method of Pyrazolo[1,5-<i>a</i>]pyridines from the Alkaline Treatment of 1-[(Acylmethylthio)methyleneamino]pyridinium Salts
Alkaline treatment of 1-[(acylmethylthio)methyleneamino]pyridinium halides gave unexpectedly 3-acyl- or 3-(acylthio)pyrazolo[1,5-a]pyridine derivatives in 35–87% yields. Some 4,4a-dihydropyrido[1,2-d][1,3,4]thiadiazine intermediates involved in these reactions could be detected by their nmr follows and three related 4a,8-dimethyl derivatives were isolated. Substituent effect and possible mechanisms