The Cinchona Primary Amine-Catalyzed Asymmetric Epoxidation and Hydroperoxidation of α,β-Unsaturated Carbonyl Compounds with Hydrogen Peroxide
作者:Olga Lifchits、Manuel Mahlau、Corinna M. Reisinger、Anna Lee、Christophe Farès、Iakov Polyak、Gopinadhanpillai Gopakumar、Walter Thiel、Benjamin List
DOI:10.1021/ja402058v
日期:2013.5.1
Using cinchona alkaloid-derived primary amines as catalysts and aqueous hydrogenperoxide as the oxidant, we have developed highly enantioselective Weitz-Scheffer-type epoxidation and hydroperoxidation reactions of α,β-unsaturated carbonylcompounds (up to 99.5:0.5 er). In this article, we present our full studies on this family of reactions, employing acyclic enones, 5-15-membered cyclic enones, and
A synthetic anionic clay, hydrotalcite (), promotes the epoxidation of electron-deficientalkenes with H2O2. With open-chain, α,β-unsaturated carbonyl compounds 3-hydroxy-1,2-dioxolanes are also obtained.
合成阴离子粘土水滑石()可以促进缺电子烯烃与H 2 O 2的环氧化。用开链,也可得到α,β-不饱和羰基化合物3-羟基-1,2-二氧戊环。
A Comparison of Intrazeolite and Solution Singlet Oxygen Ene Reactions of Allylic Alcohols
作者:Edward L. Clennan、Dong Zhang、Jamie Singleton
DOI:10.1562/2006-01-09-ra-768
日期:2006.9
of four allylic alcohols and for comparison an allylic ether have been examined both in solution and in zeolite Y. Brønsted acid sites in the zeolite were shown to inducedecomposition of several of the allylic alcohols. Treatment of the zeolites with pyridine removed these acid sites and allowed intrazeolite reactions of the allylic alcohols without interference from decomposition. Control reactions
摘要 四种烯丙醇和烯丙醚的单线态氧烯反应已在溶液和 Y 沸石中进行了检测。沸石中的布朗斯台德酸位被证明会诱导几种烯丙醇的分解。用吡啶处理沸石去除了这些酸性位点并允许烯丙醇在沸石内反应而不受分解干扰。与对分解呈惰性的烯丙醇的控制反应提供证据,证明沸石迷宫中吡啶的存在不会影响产品组成。
Hydroxy-directed regio-diastereoselective ene reaction of singlet oxygen with chiral allylic alcohols
作者:Waldemar Adam、Bernd Nestler
DOI:10.1021/ja00065a013
日期:1993.6
The photooxygenation of chiral allylic alcohols 1a, (Z)-1f-k, ethers 1b-d, and acetate 1e gave the corresponding hydroperoxy homoallylic alcohols and derivatives 2 through the enereaction with singletoxygen. While the reaction of the acetate 1e proceeded erythro-diastereoselectively as a result of the classical cis effect, for the allylic alcohols 1a and (Z)-1f-k, in which an alkyl group is located
手性烯丙醇 1a、(Z)-1f-k、醚 1b-d 和乙酸酯 1e 的光氧化反应通过与单线态氧的烯反应得到相应的氢过氧高烯丙醇和衍生物 2。由于经典的顺式效应,乙酸酯 1e 的反应以赤型非对映选择性进行,对于烯丙醇 1a 和 (Z)-1f-k,其中烷基位于带羟基的取代基的顺式,高观察到threo选择性。这一发现可以通过立体中心的亲核羟基官能团与进入的亲电子单线态氧亲烯体的配位来解释
Re<sub>2</sub>O<sub>7</sub>-catalyzed reaction of hemiacetals and aldehydes with <i>O</i>-, <i>S-,</i> and <i>C</i>-nucleophiles
作者:Wantanee Sittiwong、Michael W Richardson、Charles E Schiaffo、Thomas J Fisher、Patrick H Dussault
DOI:10.3762/bjoc.9.174
日期:——
monothioacetalization and allylation of hemiacetals. The reactions, which take place undermildconditions and at low catalyst loadings, can be conducted using hemiacetals, the corresponding O-silyl ethers, and, in some cases, the acetal dimers. Aldehydes react under similar conditions to furnish good yields of dithioacetals. Reactions of hemiacetals with nitrogen nucleophiles are unsuccessful. 1,2-Dioxolan-3-ols