Synthesis of benzofurans from the cyclodehydration of α-phenoxy ketones mediated by Eaton’s reagent
作者:Zhanwei Ma、Min Zhou、Lin Ma、Min Zhang
DOI:10.1177/1747519820907244
日期:2020.7
acid) is used to prepare 3-substituted or 2,3-disubstituted benzofurans with moderate to excellent yields under mild conditions. The method provides a facile access to benzofurans from readily available starting materials such as phenols and α-bromo ketones. The reaction is highly efficient, which is attributed to the good reactivity and fluidity of Eaton’s reagent. The reaction can be applied to prepare
Catalytic [3+3] Annulation of
<scp>β‐Ketoethers</scp>
and Cyclopropenones
<i>via</i>
C(sp
<sup>3</sup>
)—O/C—C Bond Cleavage under
<scp>Transition‐Metal</scp>
Free Conditions
carbon-oxygen (C—O) bond is highly important for the transformation of oxygen-rich biomass and industry chemicals. Herein, an efficient [3+3] annulation of β-ketoethers with cyclopropenones in the presence of catalytic base has been developed, which proceeds through the C(sp3)—O bonds cleavage in β-ketoethers and C—C bond cleavage in cyclopropenones under transition-metal free conditions. The cleavage of C(sp3)—O
Camphorsulfonic acid catalysed facile tandem double Friedlander annulation protocol for the synthesis of phenoxy linked bisquinoline derivatives and discovery of antitubercular agents
A series of phenoxy linked bisquinoline derivatives were synthesised from the Friedlander annulation of 2-(4-acetylphenoxy)-1-aryl-1-ethanones with 2-aminobenzophenone in good yields using (+/-)-camphor-10- sulfonic acid (CSA) as the catalyst. These compounds were screened for their in vitro activity against Mycobacterium tuberculosis H37Rv (MTB) and among the 23 compounds screened, 2-(3-bromophenyl)-6-chloro-3-[4-(6-chloro-4-phenyl-2-quinolyl) phenoxy]-4-phenylquinoline (3q) and 2-(4-bromophenyl)-6-chloro-3-[4-(6-chloro-4-phenyl-2-quinolyl) phenoxy]-4-phenylquinoline (3o) were found to be the most active compounds with MIC of 1.1 and 2.2 mu M against MTB. The cytotoxic effects against mouse fibroblasts (NIH 3T3) in vitro were evaluated for 3o and 3q, which displayed no toxic effects against mouse fibroblast cell line NIH 3T3. (C) 2011 Elsevier Ltd. All rights reserved.