The practical utility of decarboxylative transformations in organic synthesis is discussed, and the decarboxylative deuteration of (hetero)aromatic carboxylic acids is disclosed as a further example. Various monodeuterated arenes were synthesized under mild conditions, in a single step from easily accessible aromatic carboxylic acids and deuterium oxide. Copper catalysts were found to have the widest scope, but silver catalysts are superior for some ortho-substituted benzoates. A few substrates, e.g. quinoline-2-carboxylic acid, decarboxylate even in the absence of a metal catalyst.
mild and highly selective protocol for the monodeuteration of a variety of arenes and heteroarenes is presented. Catalytic amounts of Ag(I) salts in DMSO/D2O are shown to facilitate the deutero-decarboxylation of ortho-substituted benzoic and heteroaromatic α-carboxylic acids in high yields with excellent levels of deuterium incorporation.
提出了一种实用,温和且高度选择性的方案,用于多种芳烃和杂芳烃的单氘化。催化量的Ag(I)盐在二甲基亚砜已显示出/ D 2 O以高收率和良好的氘掺入水平促进了邻位取代的苯甲酸和杂芳族α-羧酸的氘代脱羧。
Oxidative addition of heteroaromatic halides to Negishi reagent and subsequent cross-coupling reactions
作者:Caleb F. Harris、Deepak Ravindranathan、Shouquan Huo
DOI:10.1016/j.tetlet.2012.07.105
日期:2012.10
Heteroarylzirconocene halides were prepared via the oxidative addition of heteroarylhalides to the Negishi reagent ‘Cp2ZrBu2’. The palladium-catalyzed cross-coupling of the in situ generated organozirconium reagents with functionalized aryl and heteroarylhalides proceeded smoothly in the presence of CuCl to produce the cross-coupling products in high yields.
report a unique approach to efficiently catalyze the deuteration of halogenated aromatic compounds using FePtPd nanowires (NWs) as catalysts, D as a deuteriumsource, CDOD and EtN as solvents. The advantages of this method include precise regulation of the amount of deuterium incorporation, specific targeting of the deuteration site and practical applicability for various functional groups. In addition
One-step exchange-labelling of pyridines and other N-heteroaromatics using deuterium gas: catalysis by heterogeneous rhodium and ruthenium catalysts
作者:Efstathios Alexakis、John R. Jones、William J.S. Lockley
DOI:10.1016/j.tetlet.2006.05.106
日期:2006.7
A wide range of pyridines and other nitrogen heteroaromatics can be labelled with deuterium at room temperature and pressure by isotopic exchange with deuterium gas in THF in the presence of rhodium black, ruthenium black or 5% rhodium on alumina. The labelling is rapid, isotope efficient and applicable to both electron-rich and electron-poor substrates. In a few cases, a degree of reduction accompanies the exchange. (c) 2006 Elsevier Ltd. All rights reserved.