Fluoroalkyl end-capped vinyltrimethoxysilane oligomer</span> </div> <span style="font-family:""> <div style="text-align:justify;"> <span style="font-family:&quo...Fluoroalkyl end-capped vinyltrimethoxysilane oligomer</span> </div> <span style="font-family:""> <div style="text-align:justify;"> <span style="font-family:""><span style="font-family:Verdana;">[R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(CH</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">-CHSi(OMe)</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">: </span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 2, 3, R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;"> = CF(CF</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">)OC</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">7</span></sub><span style="font-family:Verdana;">: R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">]</span></span><span style="font-family:Verdana;">,</span><span style="font-family:""><span style="font-family:Verdana;"> was applied to the facile preparation of the corresponding oligomer/sand (Ottawa </span><span style="font-family:Verdana;">sand: OS) composites [R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM-SiO</span><sub><span style="font-family:Verdana;">3/2</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">/OS] through the sol-gel reaction </span><span style="font-family:Verdana;">of the oligomer in the presence of micro-sized OS particles (590 </span></span><span style="font-family:Verdana;">-</span><span style="font-family:""><span style="font-family:Verdana;"> 840 μm) under alkaline conditions at room temperature. FE-SEM (Field Emission Scanning Electron Micrograph) images showed that the obtained composites consist of the R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM-SiO</span><sub><span style="font-family:Verdana;">3/2</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;"> oligomeric nanoparticles and the micro-sized </span><span style="font-family:Verdana;">OS particles. Interestingly, the R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM-SiO</span><sub><span style="font-family:Verdana;">3/2</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">/OS composites thus ob</span><span style="font-family:Verdana;">tained </span><span style="font-family:Verdana;">can provide the superoleophilic/superhydrophobic characteristic on the</span><span style="font-family:Verdana;"> composite surface, applying to the separation of not only the mixture of oil/water but also the W/O emulsion to isolate the transparent colorless oil. The fluorinated oligomeric OS composites were also found to be applicable to the selective removal of fluorinated aromatic compounds from </span></span><span style="font-family:Verdana;">an </span><span style="font-family:Verdana;">aqueous methanol solution. Especially, it was demonstrated that the fluorinated OS composites can supply a higher efficient and smooth separation ability for the separation of </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">mixture of oil and water than that of the corresponding fluorinated micro-sized controlled silica gel (μ-SiO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">) composites (average particle size: 9.5 μm), which were prepared under similar conditions. In addition to the separation of oil/water, the fluorinated OS composites provided higher and </span></span><span style="font-family:Verdana;">more </span><span style="font-family:""><span style="font-family:Verdana;">selective removal ability for the fluorinated aromatic compounds from aqueous solutions than that of the μ-SiO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> composites.展开更多
The site-selective C-H fluorination of heteroarenes is a straightforward approach to accessing valuable heteroaryl fluorides but remains a formidable challenge.Herein,we report a general strategy for visible-light-ind...The site-selective C-H fluorination of heteroarenes is a straightforward approach to accessing valuable heteroaryl fluorides but remains a formidable challenge.Herein,we report a general strategy for visible-light-induced C-H fluorination of heteroarenes via the merger of N-F fluorinating reagents and silane.Electron paramagnetic resonance experiments provide evidence for the homolytic cleavage of the N-F bond under blue light-emitting diode irradiation,which is the key step in the process.This transformation is metal-free,photocatalysts-free,and site-selective under mild reaction conditions(ambient temperature,visible-light irradiation,tolerant to H2O).The robustness of this protocol has also been highlighted by late-stage modification of complex and medicinally relevant molecules.展开更多
文摘Fluoroalkyl end-capped vinyltrimethoxysilane oligomer</span> </div> <span style="font-family:""> <div style="text-align:justify;"> <span style="font-family:""><span style="font-family:Verdana;">[R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(CH</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">-CHSi(OMe)</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">: </span><i><span style="font-family:Verdana;">n</span></i><span style="font-family:Verdana;"> = 2, 3, R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;"> = CF(CF</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">)OC</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;">F</span><sub><span style="font-family:Verdana;">7</span></sub><span style="font-family:Verdana;">: R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">]</span></span><span style="font-family:Verdana;">,</span><span style="font-family:""><span style="font-family:Verdana;"> was applied to the facile preparation of the corresponding oligomer/sand (Ottawa </span><span style="font-family:Verdana;">sand: OS) composites [R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM-SiO</span><sub><span style="font-family:Verdana;">3/2</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">/OS] through the sol-gel reaction </span><span style="font-family:Verdana;">of the oligomer in the presence of micro-sized OS particles (590 </span></span><span style="font-family:Verdana;">-</span><span style="font-family:""><span style="font-family:Verdana;"> 840 μm) under alkaline conditions at room temperature. FE-SEM (Field Emission Scanning Electron Micrograph) images showed that the obtained composites consist of the R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM-SiO</span><sub><span style="font-family:Verdana;">3/2</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;"> oligomeric nanoparticles and the micro-sized </span><span style="font-family:Verdana;">OS particles. Interestingly, the R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">-(VM-SiO</span><sub><span style="font-family:Verdana;">3/2</span></sub><span style="font-family:Verdana;">)</span><i><sub><span style="font-family:Verdana;">n</span></sub></i><span style="font-family:Verdana;">-R</span><sub><span style="font-family:Verdana;">F</span></sub><span style="font-family:Verdana;">/OS composites thus ob</span><span style="font-family:Verdana;">tained </span><span style="font-family:Verdana;">can provide the superoleophilic/superhydrophobic characteristic on the</span><span style="font-family:Verdana;"> composite surface, applying to the separation of not only the mixture of oil/water but also the W/O emulsion to isolate the transparent colorless oil. The fluorinated oligomeric OS composites were also found to be applicable to the selective removal of fluorinated aromatic compounds from </span></span><span style="font-family:Verdana;">an </span><span style="font-family:Verdana;">aqueous methanol solution. Especially, it was demonstrated that the fluorinated OS composites can supply a higher efficient and smooth separation ability for the separation of </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">mixture of oil and water than that of the corresponding fluorinated micro-sized controlled silica gel (μ-SiO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;">) composites (average particle size: 9.5 μm), which were prepared under similar conditions. In addition to the separation of oil/water, the fluorinated OS composites provided higher and </span></span><span style="font-family:Verdana;">more </span><span style="font-family:""><span style="font-family:Verdana;">selective removal ability for the fluorinated aromatic compounds from aqueous solutions than that of the μ-SiO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> composites.
基金financial support from the National Natural Science Foundation of China (grant no.22201121)Jiangxi Provincial Natural Science Foundation (grant nos.20224BAB213006 and 20232BAB203002).
文摘The site-selective C-H fluorination of heteroarenes is a straightforward approach to accessing valuable heteroaryl fluorides but remains a formidable challenge.Herein,we report a general strategy for visible-light-induced C-H fluorination of heteroarenes via the merger of N-F fluorinating reagents and silane.Electron paramagnetic resonance experiments provide evidence for the homolytic cleavage of the N-F bond under blue light-emitting diode irradiation,which is the key step in the process.This transformation is metal-free,photocatalysts-free,and site-selective under mild reaction conditions(ambient temperature,visible-light irradiation,tolerant to H2O).The robustness of this protocol has also been highlighted by late-stage modification of complex and medicinally relevant molecules.