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。
Controlled Ring-Opening of Siloxydifluorocyclopropanes for Carbocyclization: Synthesis of Difluorocyclopentenones
作者:Xiaoning Song、Shuangquan Tian、Ziming Zhao、Dongsheng Zhu、Mang Wang
DOI:10.1021/acs.orglett.6b01567
日期:2016.7.15
A highly controlled ring opening of siloxydifluorocyclopropanes, formed by nBuN4Br-catalyzed difluorocyclopropanation of methyl vinyl ketones bearing a β-alkylthio group by using TMSCF2Br as a unique difluorocarbene source, results in metal difluorohomoenolates with assistance of copper or silver followed by an intramolecular addition and elimination reaction leading to α-gem-difluorocyclopentenones
硅烷氧基二氟环丙烷的高度受控的开环,是通过将TMSCF 2 Br作为独特的二氟卡宾源,由n BuN 4 Br催化的带有β-烷硫基的甲基乙烯基酮的二氟环丙烷化而形成的,导致金属二氟均戊酸酯在铜或银的辅助下分子内的加成和消除反应有效地导致了α-宝石-二氟环戊烯酮。
Sulfuric Acid-Catalyzed Regioselective Alkylation of Indoles and β-Naphthols with Ketene Dithioacetal-Based Allylic Alcohols
作者:Mang Wang、Shaoguang Sun、Deqiang Liang、Bangyu Liu、Ying Dong、Qun Liu
DOI:10.1002/ejoc.201001487
日期:2011.5
alkylation of indoles with allylicalcohols has been developed. Catalyzed by sulfuric acid (10 mol-%), the reaction between indoles 2 and allylicalcohols 1 based on ketene dithioacetal affords polyfunctionalized indoles 3 in good to excellent yields with high regioselectivities under mild conditions. The catalytic carbon-carbon coupling reaction provides a facile method for the environmentally benign
Tandem [4 + 1 + 1] annulation and metal-free aerobic oxidative aromatization: straightforward synthesis of highly substituted phenols from one aldehyde and two ketones
作者:Mang Wang、Zhenqian Fu、Hui Feng、Ying Dong、Jun Liu、Qun Liu
DOI:10.1039/c0cc02313b
日期:——
Polysubstituted phenols are efficiently assembled from one aldehyde and two different methyl ketones in a one-pot operation via a newly base-induced regiospecific [4 + 1 + 1] annulation and sequential metal-free oxidative aromatization using molecular oxygen (from air) as the sole oxidant at room temperature.
Cyclization of Vinylketene Dithioacetals: A Synthetic Strategy for Substituted Thiophenes
作者:Ling Pan、Baihui Zheng、Xiaohui Yang、Liping Deng、Yifei Li、Qun Liu
DOI:10.1002/adsc.202001001
日期:2021.1.5
A synthetic strategy for the synthesis of substituted thiophenes is described by the one‐pot reaction of indoles with ketene dithioacetals under mild reaction conditions. Promoted by triflic acid (TfOH), the reaction of indoles with the easily available α‐acetyl ketene dithioacetals resulted in the formation of vinylketene dithioacetals via condensation instead of the well known nucleophilic addition‐alkylthio
AlCl<sub>3</sub>-Mediated Direct Carbon−Carbon Bond-Forming Reaction of α-Hydroxyketene-<i>S</i>,<i>S</i>-acetals with Arenes and Synthesis of 3,4-Disubstituted Dihydrocoumarin Derivatives
作者:Cheng-Ri Piao、Yu-Long Zhao、Xiao-Dan Han、Qun Liu
DOI:10.1021/jo702414y
日期:2008.3.1
α-hydroxyketene-S,S-acetals and various arenes via direct substitution of the hydroxy group in alcohols has been developed. On the basis of this C−C coupling reaction, a series of bio- and pharmacologically important 3,4-disubstituted dihydrocoumarins, difficult to obtain by other methods, were prepared in high yields by a sequential Friedel−Crafts alkylation and intramolecular annulation reaction of α-hydroxyketene