对(氧化)金催化的选定关键反应的广泛动力学研究集中在催化活性的降低,这是由于吡啶衍生物引起的金(I)催化剂的抑制,如果使用N氧化物作为副产物获得的吡啶衍生物氧气供体。不管它们的市售性如何,都已对受检吡啶衍生物及其相应的N-氧化物进行了选择。特别注意的是迄今为止在大多数反应筛选中都被忽略的实际益处。用GC和1监测测试反应1 H NMR光谱。所接收的反应常数提供了关于杂环的电子结构与催化活性之间的相关性的信息。根据收集的动力学数据,有可能开发出一套基本的三种N氧化物,这些氧化物必须在进一步的氧化金(I)催化反应中加以考虑。
Strategic Approach on <i>N</i>
-Oxides in Gold Catalysis - A Case Study
作者:Jasmin Schießl、Philipp M. Stein、Judith Stirn、Kirsten Emler、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/adsc.201801007
日期:2019.2.19
An extensive kinetic study of selected key reactions of (oxidative) goldcatalysis concentrates on the decrease of the catalytic activity due to inhibition of the gold(I) catalyst caused by pyridine derivatives that are obtained as by‐products if N‐oxides are applied as oxygen donors. The choice of the examined pyridine derivatives and their corresponding N‐oxides has been made regardless of their
对(氧化)金催化的选定关键反应的广泛动力学研究集中在催化活性的降低,这是由于吡啶衍生物引起的金(I)催化剂的抑制,如果使用N氧化物作为副产物获得的吡啶衍生物氧气供体。不管它们的市售性如何,都已对受检吡啶衍生物及其相应的N-氧化物进行了选择。特别注意的是迄今为止在大多数反应筛选中都被忽略的实际益处。用GC和1监测测试反应1 H NMR光谱。所接收的反应常数提供了关于杂环的电子结构与催化活性之间的相关性的信息。根据收集的动力学数据,有可能开发出一套基本的三种N氧化物,这些氧化物必须在进一步的氧化金(I)催化反应中加以考虑。
Silver catalyzed decarboxylative acylation of pyridine-N-oxides using α-oxocarboxylic acids
Silver catalyzed acylation of pyridine-N-oxides by α-oxocarboxylic acid is demonstrated. This decarboxylative acylation using a metal catalyst takes place at 50 °C via a radical process.
Iodo- or 2-bromopyridine N-oxides were readily magnesiated with i-PrMgCl·LiCl via the iodine or bromine−magnesium exchange. The bromine adjacent to pyridineN-oxide (at the 2- or 6-position) can be regioselectively magnesiated in the presence of other position substituted halogens. This method was tested in various substituted pyridineN-oxide systems, and has been successfully applied to the total
A New, Simple, and General Synthesis of N-Oxides of Iodopyridines and Iodoquinolines via the Diazotization–Iodination of Heterocyclic Amino N-Oxides in the Presence of p-Toluenesulfonic Acid in Water
Abstract The diazotization of a series of N-oxides of aminopyridines and aminoquinolines under the action of sodium nitrite in the presence of KI and p-TsOH in water at room temperature leads to the formation of the corresponding N-oxides of iodopyridines and iodoquinolines in high yields. The method has a general character and can be used for the preparation of 3-, 2-, and 4- N-oxides of iodopyridines