氢溴酸被发现是在C独特催化剂与烯酮二硫C键形成反应。与其他酸(包括路易斯酸和布朗斯台德酸)明显不同,氢溴酸在催化量上的显着催化性能在易于获得的官能化乙烯酮二硫缩醛1与各种亲电试剂的“酸”催化反应中观察到。在0.1当量的氢溴酸的催化下,1与羰基化合物2 a – l的反应生成多官能化的戊-1,4-二烯3或共轭二烯4产量高到极好。该反应在乙烯酮二硫缩醛1和羰基化合物2上均具有宽范围的取代基。这种有效的CC键形成方法的应用是在温和的,无金属的条件下,通过氢溴酸1与水杨醛2 m - o和对苯醌6 a - d的反应生成香豆素5和苯并呋喃7。, 分别。根据抗衡离子的性质,形成了一种新的反应性物种,即一种硫稳定的碳鎓叶立德,这被提议作为氢溴酸独特催化的关键中间体。
氢溴酸被发现是在C独特催化剂与烯酮二硫C键形成反应。与其他酸(包括路易斯酸和布朗斯台德酸)明显不同,氢溴酸在催化量上的显着催化性能在易于获得的官能化乙烯酮二硫缩醛1与各种亲电试剂的“酸”催化反应中观察到。在0.1当量的氢溴酸的催化下,1与羰基化合物2 a – l的反应生成多官能化的戊-1,4-二烯3或共轭二烯4产量高到极好。该反应在乙烯酮二硫缩醛1和羰基化合物2上均具有宽范围的取代基。这种有效的CC键形成方法的应用是在温和的,无金属的条件下,通过氢溴酸1与水杨醛2 m - o和对苯醌6 a - d的反应生成香豆素5和苯并呋喃7。, 分别。根据抗衡离子的性质,形成了一种新的反应性物种,即一种硫稳定的碳鎓叶立德,这被提议作为氢溴酸独特催化的关键中间体。
A facile and practical method for the stereospecific synthesis of α-oxoketene O,S-acetals in water has been developed. Catalyzed by tetrabutylammonium bromide at room temperature, the one-pot reaction of various β-dicarbonyl compounds, 2-bromoethanol, and carbon disulfide, in the presence of potassium carbonate, leads to the corresponding α-oxoketene O,S-acetals stereospecifically in good to excellent
Visible-Light-Induced Formation of Thiavinyl 1,3-Dipoles: A Metal-Free [3+2] Oxidative Cyclization with Alkynes as Easy Access to Thiophenes
作者:Baihui Zheng、Xiaotong Li、Yang Song、Shuyang Meng、Yifei Li、Qun Liu、Ling Pan
DOI:10.1021/acs.orglett.1c00915
日期:2021.5.7
previously unknown thiavinyl 1,3-dipoles in the presence of an acridine photosensitizer is reported. A series of multisubstituted thiophenes were achieved regioselectively in ≤98% yields under very mild metal-free conditions without other additives. This reaction could tolerate a wide range of substrates and achieve good efficiency in large-scale syntheses. The reaction mechanism and their applications
Synthesis of γ-pyrone precursors by condensation of acetyl ketene dithioacetals with ethyl polyfluorocarboxylates and diethyl oxalate
作者:Sergey A. Usachev、Vyacheslav Ya. Sosnovskikh
DOI:10.1007/s10593-017-2000-5
日期:2016.12
β-Dicarbonyl compounds with the ketene dithioacetyl fragment were obtained by condensation of acetyl ketene dithioacetals with ethyl polyfluorocarboxylates and diethyl oxalate in the presence of NaH in Et2O at room temperature in 65–94% yields. These compounds can be used for the synthesis of 6-polyfluoroalkyl(ethoxycarbonyl)-2-methylsulfanyl-4-pyrones.
Friedel–Crafts Coupling of Electron-Deficient Benzoylacetones Tuned by Remote Electronic Effects
作者:Hongmei Luo、Ling Pan、Xianxiu Xu、Qun Liu
DOI:10.1021/acs.joc.5b01371
日期:2015.8.21
electrophilic substitutions and remains a major challenge. Herein, the synthesis of naphthoquinones and 1,3-indandiones, bearing two acyl groups at positions ortho to each other on a benzene ring, are demonstrated by means of copper-catalyzed intramolecular aerobic oxidative acylation of benzoylacetone derivative precursors. This unusual Friedel–Crafts reaction reveals a new activation mode for the
A tandem reaction of 2-acetylmethylene-1,3-dithiolanes via fragmentation of the dithiolane ring in the presence of amines: a facile route to functionalized thioamides
作者:Fushun Liang、Yan Li、Dazhi Li、Xin Cheng、Qun Liu
DOI:10.1016/j.tetlet.2007.09.065
日期:2007.11
A facile and efficient route to functionalized thioamides has been developed by a tandem reaction of 2-acetylmethylene-1,3-dithiolanes via fragmentation of the dithiolane ring upon heating and in the presence of an amine.