Substituent effects of cis-cinnamic acid analogues as plant growh inhibitors
摘要:
1-O-cis-Cinnamoyl-beta-D-glucopyranose is one of the most potent allelochemicals that has been isolated from Spiraea thunbergii Sieb by Hiradate et al. It derives its strong inhibitory activity from cis-cinnamic acid (cis-CA), which is crucial for phytotoxicity. By preparing and assaying a series of cis-CA analogues, it was previously found that the key features of cis-CA for lettuce root growth inhibition are a phenyl ring, cis-configuration of the alkene moiety, and carboxylic acid. On the basis of a structure-activity relationship study, the substituent effects on the aromatic ring of cis-CA were examined by systematic synthesis and the lettuce root growth inhibition assay of a series of cis-CA analogues having substituents on the aromatic ring. While ortho- and para-substituted analogues exhibited low potency in most cases, meta-substitution was not critical for potency, and analogues having a hydrophobic and sterically small substituent were more likely to be potent. Finally, several cis-CA analogues were found to be more potent root growth inhibitors than cis-CA. (C) 2013 Elsevier Ltd. All rights reserved.
Substituent effects of cis-cinnamic acid analogues as plant growh inhibitors
摘要:
1-O-cis-Cinnamoyl-beta-D-glucopyranose is one of the most potent allelochemicals that has been isolated from Spiraea thunbergii Sieb by Hiradate et al. It derives its strong inhibitory activity from cis-cinnamic acid (cis-CA), which is crucial for phytotoxicity. By preparing and assaying a series of cis-CA analogues, it was previously found that the key features of cis-CA for lettuce root growth inhibition are a phenyl ring, cis-configuration of the alkene moiety, and carboxylic acid. On the basis of a structure-activity relationship study, the substituent effects on the aromatic ring of cis-CA were examined by systematic synthesis and the lettuce root growth inhibition assay of a series of cis-CA analogues having substituents on the aromatic ring. While ortho- and para-substituted analogues exhibited low potency in most cases, meta-substitution was not critical for potency, and analogues having a hydrophobic and sterically small substituent were more likely to be potent. Finally, several cis-CA analogues were found to be more potent root growth inhibitors than cis-CA. (C) 2013 Elsevier Ltd. All rights reserved.
Gold(<scp>i</scp>)-catalyzed cross-coupling reactions of aryldiazonium salts with organostannanes
作者:Manjur O. Akram、Popat S. Shinde、Chetan C. Chintawar、Nitin T. Patil
DOI:10.1039/c8ob00630j
日期:——
Gold(I)-catalyzed cross-couplingreactions of aryldiazonium salts with organostannanes are described. This redox neutral strategy offers an efficient approach to diverse biaryls, vinyl arenes and arylacetylenes. Monitoring the reaction with NMR and ESI-MS provided strong evidence for the in situ formation of Ph3PAuIR (R = aryl, vinyl and alkynyl) species which is crucial for the activation of aryldiazonium
描述了金(I)催化的芳基重氮盐与有机锡烷的交叉偶联反应。这种氧化还原中性策略为各种联芳基,乙烯基芳烃和芳基乙炔提供了一种有效的方法。用NMR和ESI-MS监测反应为原位形成Ph 3 PAu I R(R =芳基,乙烯基和炔基)物种提供了有力证据,这对于激活芳基重氮盐至关重要。