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。
Regio- and stereoselective synthesis of 2-cyclopentenones via a hydrogenolysis-terminated Heck cyclization of β-alkylthio dienones
作者:Bangyu Liu、Gang Zheng、Xiaocui Liu、Cong Xu、Jingxin Liu、Mang Wang
DOI:10.1039/c3cc37571d
日期:——
Palladium-catalyzed cyclization of β-alkylthio dienone derivatives affords 2-cyclopentenones in a regio- and stereoselective manner in the presence of silane. CâS activation, intramolecular carbopalladation and hydrogenolysis construct the cascade process.
Iron(III) Chloride Promoted Desulfitative C–C Coupling Reaction of α-Oxo Ketene Dithioacetals and Indoles: Highly Selective Synthesis of β,β-Bisindolyl and β-Indolyl α,β-Unsaturated Carbonyl Compounds
作者:Haifeng Yu、Tiechun Li、Peiqiu Liao
DOI:10.1055/s-0032-1317691
日期:——
Abstract The iron(III) chloridepromoted desulfitative C–C coupling of α-oxo ketene dithioacetals with indoles was developed for the synthesis of indole derivatives. In the presence of iron(III) chloride, α-oxo ketene dithioacetals reacted efficiently and highly selectively with C2-unsubstituted or C2-substituted indoles to afford excellent yields of β,β-bisindolyl or β-indolyl α,β-unsaturated carbonyl
Synthesis of γ-Pyrones from Formal [4 + 2] Cyclization of Ketene Dithioacetals with Acyl Chlorides
作者:Mingshan Wang、Lou Shi、Yifei Li、Qun Liu、Ling Pan
DOI:10.1021/acs.joc.9b01254
日期:2019.8.2
been developed. Mediated by lithium bis(trimethylsilyl)amide, a series of γ-pyrones were obtained with a broad substrate scope. This unprecedented formal [4 + 2] cyclization provides a novel mode for ketene dithioacetals as versatile synthons. The synthesized γ-pyrones could be successfully transformed to 2-aryl/amino γ-pyrones and 2,3-dihydroimidazo[1,2-a]pyridin-7(1H)-ones mainly via the cleavage of
已开发出容易获得的乙烯酮二硫缩醛与酰氯的正式[4 + 2]环化反应。在双(三甲基甲硅烷基)酰胺锂的介导下,获得了一系列具有较宽底物范围的γ-吡喃酮。这种前所未有的形式化[4 + 2]环化为烯酮二硫缩醛作为通用合成子提供了一种新颖的模式。合成的γ-吡喃酮主要通过C–S键的裂解成功转化为2-芳基/氨基γ-吡喃酮和2,3-二氢咪唑并[1,2 - a ]吡啶-7(1 H)-酮。 。
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