38768-63-7Relevant articles and documents
Design and Synthesis of Novel 4-Hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one Derivatives for Use as Herbicides and Evaluation of Their Mode of Action
Lei, Kang,Li, Pan,Yang, Xue-Fang,Wang, Shi-Ben,Wang, Xue-Kun,Hua, Xue-Wen,Sun, Bin,Ji, Lu-Sha,Xu, Xiao-Hua
, p. 10489 - 10497 (2019/10/02)
In order to develop a novel herbicide containing the β-triketone motif, a series of 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one derivatives were designed and synthesized. The bioassay results showed that compound II15 had good pre-emergent herbicidal activity even at a dosage of 187.5 g ha-1. Moreover, compound II15 showed a broader spectrum of weed control when compared with a commercial herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), and displayed good crop safety to Triticum aestivum L. and Zea mays Linn. when applied at 375 g ha-1 under pre-emergence conditions, which indicated its great potential as a herbicide. More importantly, studying the molecular mode of action of compound II15 revealed that the novel triketone structure is a proherbicide of its corresponding phenoxyacetic acid auxin herbicide, which has a herbicidal mechanism similar to that of 2,4-D. The present work indicates that the 4-hydroxyl-3-(2-phenoxyacetyl)-pyran-2-one motif may be a potential lead structure for further development of novel auxin-type herbicides.
Synthesis and molecular structures of 1-hydroxyethyl-2-(p-substituted) phenoxymethyl benzimidazoles
Wu, Jiacheng,Zhao, Li,Zhao, Changqing,Wang, Zhiyuan,Gu, Haibin,Chen, Wuyong
, p. 974 - 980 (2016/11/22)
Five novel 1-hydroxyethyl-2-(p-substituted) phenoxymethyl benzimidazoles were synthesized by a three-step route. Under microwave irradiation, the p-substituted phenols were firstly O-carboxymethylated to prepare the corresponding p-substituted phenoxymethyl acids, which then reacted with o-phenylendiamine to get the key intermediates 2-(p-substituted) phenoxymethyl benzimidazole. Finally, the solid-liquid phase transfer catalysis method, where tetrabutyl ammonium bromide (TBAB) was used as the catalyst, was applied to synthesize the target compounds c1-c5 by the N-hydroxyethylation reaction with 2-chloroethyl alcohol. The structures of the obtained compounds were well characterized and confirmed by elemental analysis, MS, IR, 1H NMR, 13C NMR and single-crystal X-ray diffraction analysis.
Catalyst-free photoredox addition-cyclisations: Exploitation of natural synergy between aryl acetic acids and maleimide
Manley, David W.,Mills, Andrew,O'Rourke, Christopher,Slawin, Alexandra M. Z.,Walton, John C.
supporting information, p. 5492 - 5500 (2014/05/20)
Suitably functionalised carboxylic acids undergo a previously unknown photoredox reaction when irradiated with UVA in the presence of maleimide. Maleimide was found to synergistically act as a radical generating photoxidant and as a radical acceptor, negating the need for an extrinsic photoredox catalyst. Modest to excellent yields of the product chromenopyrroledione, thiochromenopyrroledione and pyrroloquinolinedione derivatives were obtained in thirteen preparative photolyses. In situ NMR spectroscopy was used to study each reaction. Reactant decay and product build-up were monitored, enabling reaction profiles to be plotted. A plausible mechanism, whereby photo-excited maleimide acts as an oxidant to generate a radical ion pair, has been postulated and is supported by UV/Vis. spectroscopy and DFT computations. The radical-cation reactive intermediates were also characterised in solution by EPR spectroscopy. UVA photolyses of aryloxy-, arylthio- and arylamino-acetic acids with maleimide yield oxa-, thia- and aza-tricyclo pyrroledione derivatives in the absence of a photoredox catalyst (see scheme). An intriguing mechanism has been proposed and has been supported and supplemented by NMR monitoring experiments, DFT computations and UV/Vis and EPR spectroscopy.
