4-CH<sub>3</sub>CONH-TEMPO/Peracetic Acid System for a Shortened Electron-Transfer-Cycle-Controlled Oxidation of Secondary Alcohols
作者:Shufang Zhang、Chengxia Miao、Chungu Xia、Wei Sun
DOI:10.1002/cctc.201500214
日期:2015.6.15
catalyzed oxidation of secondaryalcohols with peracetic acid as the oxidant, which was generated from H2O2 and acetic acid catalyzed by strongly acidic resins. The oxidation of alcohols proceeded well through a shortened electron‐transfer cycle under metal‐free conditions, avoiding the use of any other electron‐transfer mediators such as halides. In addition, we demonstrated that the present system exhibited
我们已经开发了一种2,2,6,6-四甲基哌啶-1-氧基(TEMPO)衍生物以过氧乙酸为氧化剂催化仲醇氧化的方法,该过氧化氢是由H 2 O 2和强酸性树脂催化的乙酸产生的。在无金属条件下,醇的氧化通过缩短的电子转移周期进行得很好,避免了使用任何其他电子转移介体,例如卤化物。另外,我们证明了本系统在温和条件下对芳族,脂族和烯丙基仲醇的氧化表现出优异的效率。
Tethered Aminohydroxylation: Dramatic Improvements to the Process
作者:Timothy J. Donohoe、Carole J. R. Bataille、William Gattrell、Johannes Kloesges、Emilie Rossignol
DOI:10.1021/ol070430v
日期:2007.4.1
[reaction: see text] Changing the identity of the N leaving group on a hydroxylamine-based reoxidant gives a dramatic improvement to the tetheredaminohydroxylationreaction. Using OCOC6F5 as a leaving group means that only 1 mol % of osmium is required and yields as high as 98% can be obtained. Acyclic homoallylic alcohols were substrates considered too unreactive for effective use in the tethered
<i>N</i>-Sulfonyloxy Carbamates as Reoxidants for the Tethered Aminohydroxylation Reaction
作者:Timothy J. Donohoe、Majid J. Chughtai、David J. Klauber、David Griffin、Andrew D. Campbell
DOI:10.1021/ja057389g
日期:2006.3.1
for the tetheredaminohydroxylation (TA) reaction is reported. These new conditions obviate the requirement for lithium hydroxide and tBuOCl in the oxidation mixture. In addition to providing aminohydroxylation products in good yields, the catalyst loadings can be reduced to just 1 mol % osmium. Moreover, for the first time, homoallylic alcohols are now viable substrates for the TA reaction.
Kinetic resolution of racemic allylic alcohols <i>via</i> iridium-catalyzed asymmetric hydrogenation: scope, synthetic applications and insight into the origin of selectivity
作者:Haibo Wu、Cristiana Margarita、Jira Jongcharoenkamol、Mark D. Nolan、Thishana Singh、Pher G. Andersson
DOI:10.1039/d0sc05276k
日期:——
Asymmetric hydrogenation is one of the most commonly used tools in organic synthesis, whereas, kineticresolution via asymmetric hydrogenation is less developed. Herein, we describe the first iridium catalyzed kineticresolution of a wide range of trisubstituted secondary and tertiary allylic alcohols. Large selectivity factors were observed in most cases (s up to 211), providing the unreacted starting
不对称氢化是有机合成中最常用的工具之一,而通过不对称氢化进行动力学拆分的开发较少。在此,我们描述了各种三取代仲和叔烯丙醇的第一次铱催化动力学拆分。在大多数情况下观察到较大的选择性因子(高达211),从而以良好的收率和高水平的对映体纯度(ee 高达 >99%)提供未反应的起始材料。该方法的实用性在一些生物活性天然产物的对映选择性正式合成中得到了强调,包括 pumiliotoxin A、inthomycin A 和 B。提出了 DFT 研究和关于选择性起源的选择性模型。
Efficient Acyclic Stereocontrol Using the Tethered Aminohydroxylation Reaction
作者:Timothy J. Donohoe、Peter D. Johnson、Richard J. Pye、Martine Keenan
DOI:10.1021/ol049136i
日期:2004.7.1
[reaction: see text] The tetheredaminohydroxylation (TA) of acyclic allylic carbamates has been achieved in a stereospecific and stereoselective manner. Unusually high levels of stereocontrol were observed in the oxidation of 1,1-disubstituted substrates.