Ionic liquid brush as an efficient and reusable heterogeneous catalytic assembly for the tosylation of phenols and alcohols in neat water
作者:Simin Feng、Jing Li、Junfa Wei
DOI:10.1039/c7nj00141j
日期:——
A very efficient and reusable heterogeneous ionicliquidbrush assembly was developed. The catalyst exhibits high catalytic activity for the tosylation of phenols and alcohols in neat water. Moreover, the catalyst shows outstanding stability and reusability, and it can be simply and effectively recovered and reused five times without noticeable loss of catalytic activity.
Mechanistic Insights into the Palladium-Catalyzed Domino Synthesis of 10,11-Dihydro-5<i>H</i>-dibenzo[<i>b</i>,<i>e</i>][1,4]diazepines
作者:Joydev K. Laha、K. S. Satyanarayana Tummalapalli、Ankur Gupta
DOI:10.1002/ejoc.201402207
日期:2014.8
A palladium-catalyzed domino approach to the synthesis of 10,11-dihydro-5H-dibenzo[b,e][1,4]diazepines starting from o-phenylenediamines and 2-bromobenzyl bromides or tosylates has been developed. Mechanistic studies support the following domino sequence. Intermolecular mono-N-benzylation of the o-phenylenediamine through oxidative palladium insertion, primarily at the benzylic position of the 2-bromobenzyl
Assembly of 4H-chromenes, imidazobenzothiazines and quinazolines via copper-catalyzed domino reactions using 2-halobenzyl tosylates as substrates
作者:Mohamed A. Omar、Jürgen Conrad、Uwe Beifuss
DOI:10.1016/j.tet.2014.06.071
日期:2014.9
The use of 2-halobenzyl tosylates as substrates in copper-catalyzed domino intermolecular substitution/intramolecular arylation processes for the efficient and selective preparation of heterocycles is reported for the first time. Reaction of 2-halobenzyl tosylates with beta-ketoesters delivers 4H-chromenes with yields ranging between 59 and 89%. Imidazobenzothiazines are formed with yields up to 82% upon reaction of 2-halobenzyl tosylates with 2-mercaptoimidazoles. When 2-halobenzyl tosylates are reacted with benzamidines the corresponding quinazolines are obtained. (C) 2014 Elsevier Ltd. All rights reserved.