Atmospheric CO<sub>2</sub> promoted synthesis of N-containing heterocycles over B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> catalyst
作者:Xiang Gao、Bo Yu、Qingqing Mei、Zhenzhen Yang、Yanfei Zhao、Hongye Zhang、Leiduan Hao、Zhimin Liu
DOI:10.1039/c6nj01721e
日期:——
B(C6F5)3 combined with atmospheric CO2 was found to be highly effective for the cyclization of ortho-substituted aniline derivatives with N,N-dimethylformamide (DMF), and a series of N-containing heterocycles including benzothiazoles, benzimidazoles, quinazolinone and benzoxazole were obtained in good to excellent yields.
发现B(C 6 F 5)3与大气CO 2结合对于N,N-二甲基甲酰胺(DMF)和一系列含N的杂环(包括苯并噻唑,苯并咪唑)的邻位取代苯胺衍生物的环化非常有效以良好至优异的产率获得喹唑啉酮和苯并恶唑。
Ionic Liquid-Catalyzed C–S Bond Construction using CO<sub>2</sub> as a C1 Building Block under Mild Conditions: A Metal-Free Route to Synthesis of Benzothiazoles
作者:Xiang Gao、Bo Yu、Zhenzhen Yang、Yanfei Zhao、Hongye Zhang、Leiduan Hao、Buxing Han、Zhimin Liu
DOI:10.1021/acscatal.5b01874
日期:2015.11.6
The construction of the C–S bond using CO2 as a C1 feedstock can be considered as a green route for the synthesis of S-containing compounds and is of great significance. Herein, we report the acetate-based ionic liquids (ILs)-catalyzed synthesis of benzothiazoles via cyclization of 2-aminothiophenols with CO2 and hydrosilane under mild conditions (e.g., 60 °C, 0.5 MPa). It was found that the IL (e
Compounds of formula (I)
are useful in treating conditions or disorders prevented by or ameliorated by histamine-3 receptor ligands. Also disclosed are pharmaceutical compositions comprising the histamine-3 receptor ligands, methods for using such compounds and compositions, and a process for preparing compounds within the scope of formula (I).
Ionic liquid promoted spiroannulation via hetero-Michael addition and intramolecular heterocyclisation
作者:I. R. Siddiqui、Shireen、Shayna Shamim、Afaf A. H. Abumhdi、Malik A. Waseem、Arjita Srivastava、Rahila、Anjali Srivastava
DOI:10.1039/c3nj41070f
日期:——
spiro-5-thiazolidin-2-one-indolo[1,5]benzothiazepine from readily available isatin, 4-thioxothiazolidin-2-one and 2-aminothiophenol is reported. The synthesis involves formation of N-methyl-3-(2-oxo-4-thioxothiazolidinon-5-ylidene)-1,3-dihydro indol-2-one by [bmIm]OH promoted Knoevenagelcondensation of 4-thioxo-2-thiazolidinone with isatin. The Knoevenagel product on ionic liquid promoted thia-Michael addition with
Synthesis of benzothiazoles from 2-aminobenzenethiols in the presence of a reusable polythiazolium precatalyst under atmospheric pressure of carbon dioxide
作者:Supill Chun、Sabyuk Yang、Young Keun Chung
DOI:10.1016/j.tet.2017.05.003
日期:2017.6
Synthesis of benzothiazoles from 2-aminobenzenethiols and carbondioxide was carried out using poly(3,4-dimethyl-5-vinylthiazolium) iodide as a precatalyst to in situ generation of NHCs by deprotonation. The reaction was successfully carried out under mild conditions (1 atm of CO2 and 60–70 °C) with a broad substrate scope and functional group tolerance. The precatalyst salt was recovered and reused