A novel protocol for the efficient activation of the Beckmannrearrangement utilizing the readily available sulfuryl fluoride (SO2F2 gas) is reported. The substrate scope of this methodology has been demonstrated by 37 examples with good to nearly quantitative isolated yields in a short time. A tentative mechanism was proposed involving formation and elimination of sulfonyl ester.
报道了一种利用容易获得的硫酰氟(SO 2 F 2气体)有效激活贝克曼重排的新方案。该方法的底物范围已通过37个实例证明,并在短时间内获得了良好至近乎定量的分离产率。提出了一种尝试性的机制,涉及形成和消除磺酰基酯。
Oxime‐derived palladacycle Immobilized in an Ionic Liquid Brush as an Efficient and Reusable Catalyst for Mozoroki‐Heck Reaction in Neat Water
作者:Rong Wang、Shan Li、Jing Li、Junfa Wei
DOI:10.1002/aoc.5226
日期:2019.11
An efficient and reusable heterogeneous catalyst with oxime‐derived palladacycle immobilized in an ionic liquid brush has been synthesized and an environmentally‐friendly procedure have been developed for coupling aryl iodides and bromides with acrylic acid. These reactions were conducted in neat water under aerobic conditions with water‐insoluble or even solid arylhalides and they proceeded smoothly
Radical Beckmann Rearrangement and Its Application in the Formal Total Synthesis of Antimalarial Natural Product Isocryptolepine via C–H Activation
作者:Pankaj S. Mahajan、Vivek T. Humne、Subhash D. Tanpure、Santosh B. Mhaske
DOI:10.1021/acs.orglett.6b01634
日期:2016.7.15
ketoximes, mediated by ammonium persulfate-dimethyl sulfoxide as a reagent, has been achieved under neutral conditions. Based on the radical trapping and 18O-labeling experiments, the transformation follows a mechanism involving a radical pathway. The scope and generality of the developed protocol has been demonstrated by 19 examples. The developed protocol and Pd-catalyzed intramolecular double C–H
Cross-coupling reactions with boronic acids in water catalysed by oxime-derived palladacycles
作者:Luis Botella、Carmen Nájera
DOI:10.1016/s0022-328x(02)01727-8
日期:2002.12
Palladacycles derivedfrom phenone-oximes 1 are efficient precatalysts for the Suzuki–Miyaura coupling of arylboronic acids with aromatic and heteroaromatic bromides and chlorides under water reflux under aerobic conditions. Alternatively, the coupling can also be carried out at room temperature in methanol–water. Aryl bromides gave biaryls with TON up to 105 and TOF up to 7×104 h−1. Activated and
衍生自苯酮肟1的Palladacycles是有氧条件下在水回流下芳烃硼酸与芳族和杂芳族溴化物和氯化物的Suzuki-Miyaura偶联的有效预催化剂。或者,也可以在室温下在甲醇-水中进行偶联。芳基溴化物使联芳基的TON高达10 5,TOF高达7×10 4 h -1。活化和失活的芳基氯化物需要存在TBAB才能偶联,表现出稍低的效率(TON高达9000,TOF高达3850 h -1)。C(sp 2)C(sp 3)也可以通过三甲基环硼氧烷和丁基硼酸与芳族溴化物和氯化物在水回流下以及苄基和烯丙基氯化物或乙酸酯与芳基硼酸在丙酮-水中在室温下的交叉偶联反应形成。
Scope and Mechanism of a True Organocatalytic Beckmann Rearrangement with a Boronic Acid/Perfluoropinacol System under Ambient Conditions
作者:Xiaobin Mo、Timothy D. R. Morgan、Hwee Ting Ang、Dennis G. Hall
DOI:10.1021/jacs.8b01618
日期:2018.4.18
enylboronic acid were identified as efficient catalysts for the direct and chemoselective activation of oxime N-OH bonds in the Beckmann rearrangement. This classical organic reaction provides a unique approach to prepare functionalized amide products that may be difficult to access using traditional amide coupling between carboxylic acids and amines. Using only 5 mol % of boronic acid catalyst and