Electrochemical oxidation of 1-chloro(bromo)-2,2,6,6-tetramethylpiperidines
摘要:
Electrochemical oxidation of 1-haloamines of the 2,2,6,6-tetramethylpiperidine series results in the formation of relatively stable radical-cations, detected by the methods of cyclic voltammetry and ESR spectroscopy. The final products of electrochemical oxidation of these haloamines are stable nitroxyl radicals.
氯从氯胺-T(CAT)转移到几种胺的动力学和机理是二阶的,与对甲苯磺酰胺的浓度无关。因此,该反应不涉及CAT向二氯胺-T的歧化。根据pH与速率的关系曲线,提出了以下机理:(1)CAT的离子化种类与电离胺的反应(离子机理)和(2)CAT的非离子化种类与未电离的反应胺(非离子机理)。计算的离子和非离子机理的二阶,pH无关速率常数分别为1.6和5 x 10(6)M-1 s-1。尽管这两种机制在动力学上是无法区分的,非离子机理的速率常数与针对涉及不可离子化的氯胺(例如N-氯琥珀酰亚胺,N-氯喹核苷和N-氯-N-甲基苯磺酰胺)的类似氯化反应计算的速率常数处于相同数量级。提出的氯交换机理涉及处于环状六元过渡态的水分子。
[EN] PROCESS FOR PREPARING CHLOROAMINES<br/>[FR] PROCÉDÉ DE PRÉPARATION DE CHLORAMINES
申请人:BAYER IP GMBH
公开号:WO2013120874A1
公开(公告)日:2013-08-22
The present application relates to a process for preparing chloroamines which can be used as precursors for syntheses of fine chemicals and active ingredients from pharmaceuticals and/or agriculture, by reaction of secondary amines of the formula (II) with chlorine gas in the presence of an aqueous alkali metal or alkaline earth metal oxide base.
2,2,6,6-Tetramethylpiperidine-Catalyzed, Ortho-selective Chlorination of Phenols by Sulfuryl Chloride
作者:Noam I. Saper、Barry B. Snider
DOI:10.1021/jo402424h
日期:2014.1.17
6-Tetramethylpiperidine (TMP)-catalyzed (1–10%) chlorinations of phenols by SO2Cl2 in aromatic solvents are more ortho selective than with primary and less hindered secondary amine catalysts. Ortho-selective chlorination is successful even with electron deficient phenols such as 2-hydroxybenzaldehyde and 2′-hydroxyacetophenone. Notably, ortho selectivity increases with the reaction temperature. On the other hand,
Palladium-Catalyzed Zinc-Amide-Mediated CH Arylation of Fluoroarenes and Heteroarenes with Aryl Sulfides
作者:Shinya Otsuka、Hideki Yorimitsu、Atsuhiro Osuka
DOI:10.1002/chem.201502101
日期:2015.10.12
heteroarenes with aryl sulfides proceeds smoothly with the aid of a palladium–N‐heterocyclic carbene catalyst. A bulky zinc amide, TMPZnCl⋅LiCl, plays a key role as an effective base to generate the corresponding arylzinc species in situ. This arylation protocol is practically much easier to perform than our previous method, which necessitates preparation of the arylzincreagents in advance from the corresponding
Ç polyfluoroarenes和杂芳烃的与芳基硫化物ħ芳基化用钯- N-杂环卡宾催化剂的帮助下顺利进行。甲笨重锌酰胺,TMPZnCl ⋅的LiCl,起着以原位产生相应的芳基锌物种的有效碱关键作用。该芳基化方案实际上比我们以前的方法更容易执行,后者需要从相应的芳基卤化物预先制备芳基锌试剂。通过硫特异性反应(如S N Ar磺酰化反应和扩展的Pummerer反应)制备的芳基硫化物会经历这种直接芳基化,从而提供有趣的转化,而这些转化是传统的基于卤素的有机合成难以实现的。
[EN] PREPARATION OF ALKALINE EARTH METAL-COMPLEXED METAL BISAMIDES FROM METAL MONOAMIDES<br/>[FR] PRÉPARATION DE BISAMIDES DE MÉTAL FORMANT UN COMPLEXE AVEC UN MÉTAL ALCALINO-TERREUX À PARTIR DE MONOAMIDES DE MÉTAL
申请人:BAYER CROPSCIENCE AG
公开号:WO2014124915A1
公开(公告)日:2014-08-21
The present invention relates to a process for preparing alkaline earth metal-complexed metal bisamides of the formula (I) from metal monoamides of the formula (II). The present invention further relates to a process for preparing alkaline earth metal monoamides of the formula (II-AE), to novel LiCl-free alkaline earth metal monoamides of the formula (II-AE-L), and to the use of these alkaline earth metal monoamides for metallation of aromatics, heteroaromatics, alkenes, alkynes and other organic compounds having activated C-H bonds.
[EN] ALKALINE EARTH METAL-COMPLEXED METAL BISAMIDES<br/>[FR] BISAMIDES MÉTALLIQUES COMPLEXÉS PAR DES MÉTAUX ALCALINO-TERREUX
申请人:BAYER IP GMBH
公开号:WO2013120911A1
公开(公告)日:2013-08-22
The present invention relates to alkaline earth metal-complexed metal bisamides of the formula (I), to a process for preparation thereof and to the use thereof for metallation of aromatics, heteroaromatics, alkenes, alkynes and other organic compounds having activated C-H bonds.