Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis.Here,we introduce the development of a visible-light catalytic direct reduction coupling reaction betweenα-CF_(3)-...Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis.Here,we introduce the development of a visible-light catalytic direct reduction coupling reaction betweenα-CF_(3)-alkyl bromides and alkynyl bromides to access valuable organic frameworks.Our research confirms the excellent compatibility of this reaction with various functional groups,which could be used to modify the substrate with biologically active molecular fragments.Mechanistic investigations,including control experiments,fluorescence quenching studies,and light-switching experiments,have provided insights into the reaction mechanism.This study paves the way for the application of visible-light catalysis in diverse synthetic transformations,offering a sustainable and efficient approach to organic synthesis.展开更多
综合采用红外光谱(FTIR)、核磁碳谱(13 C NMR)、差示扫描量热(DSC),热失重测试(TGA)等多种表征手段,研究了聚硅芳炔(PAR)和聚硅乙炔(PMR)两种含硅炔基树脂的固化行为,讨论了树脂固化物的结构与热稳定性的关系。结果表明:PAR和PMR树脂的...综合采用红外光谱(FTIR)、核磁碳谱(13 C NMR)、差示扫描量热(DSC),热失重测试(TGA)等多种表征手段,研究了聚硅芳炔(PAR)和聚硅乙炔(PMR)两种含硅炔基树脂的固化行为,讨论了树脂固化物的结构与热稳定性的关系。结果表明:PAR和PMR树脂的固化机理不同,PAR主要通过炔基间的加成和Diels-Alder反应实现分子间的固化交联,并最终形成由苯环和稠芳环组成的芳构网络;PMR则主要通过硅氢基、炔基、烯基之间的加成反应实现固化,并成形饱和的碳硅Si—C(sp3)网络结构。固化成型的芳构网络和Si—C(sp3)网络结构分别赋予了PAR和PMR树脂固化物良好的热稳定性能,它们的热分解温度Td5均大于600℃,900℃残重率均达到85%以上。展开更多
A variety of rigid ruthenium and osmium allenylidene, ruthenium alkynyl-allenylidene complexes have been prepared. These allenylidene complexes were derived from 9-ethynyl-9-fluorenol and 9-hydroxy-9-ethynyl-4,5-diaza...A variety of rigid ruthenium and osmium allenylidene, ruthenium alkynyl-allenylidene complexes have been prepared. These allenylidene complexes were derived from 9-ethynyl-9-fluorenol and 9-hydroxy-9-ethynyl-4,5-diazafluorene in the presence of cis-OsCl2（dppm）2 and cis-RuCl2（dppe）2. The respective products have been fully characterized by 1H, 13C, 31P NMR spectrometry, IR spectrometry, elemental analysis, and UV/Vis spectrophotometry. Moreover, electrochemical studies reveal that the dinuclear complexes display a quasi-reversible redox behavior and a moderate electronic communication between the two metal centers in 8a. UV–vis studies show a remarkable absorption in the region （λmax = 300-700 nm） for these complexes.展开更多
基金support was from Tianjin University(2024XJD-0062)the National Natural Science Foundation of China(No.22371203).
文摘Traditional reduction coupling reactions of two bromides typically rely on transition metal catalysis.Here,we introduce the development of a visible-light catalytic direct reduction coupling reaction betweenα-CF_(3)-alkyl bromides and alkynyl bromides to access valuable organic frameworks.Our research confirms the excellent compatibility of this reaction with various functional groups,which could be used to modify the substrate with biologically active molecular fragments.Mechanistic investigations,including control experiments,fluorescence quenching studies,and light-switching experiments,have provided insights into the reaction mechanism.This study paves the way for the application of visible-light catalysis in diverse synthetic transformations,offering a sustainable and efficient approach to organic synthesis.
文摘综合采用红外光谱(FTIR)、核磁碳谱(13 C NMR)、差示扫描量热(DSC),热失重测试(TGA)等多种表征手段,研究了聚硅芳炔(PAR)和聚硅乙炔(PMR)两种含硅炔基树脂的固化行为,讨论了树脂固化物的结构与热稳定性的关系。结果表明:PAR和PMR树脂的固化机理不同,PAR主要通过炔基间的加成和Diels-Alder反应实现分子间的固化交联,并最终形成由苯环和稠芳环组成的芳构网络;PMR则主要通过硅氢基、炔基、烯基之间的加成反应实现固化,并成形饱和的碳硅Si—C(sp3)网络结构。固化成型的芳构网络和Si—C(sp3)网络结构分别赋予了PAR和PMR树脂固化物良好的热稳定性能,它们的热分解温度Td5均大于600℃,900℃残重率均达到85%以上。
基金This research was supported by the National Natural Science Foundation of China （Nos. 21332002）.
文摘A variety of rigid ruthenium and osmium allenylidene, ruthenium alkynyl-allenylidene complexes have been prepared. These allenylidene complexes were derived from 9-ethynyl-9-fluorenol and 9-hydroxy-9-ethynyl-4,5-diazafluorene in the presence of cis-OsCl2（dppm）2 and cis-RuCl2（dppe）2. The respective products have been fully characterized by 1H, 13C, 31P NMR spectrometry, IR spectrometry, elemental analysis, and UV/Vis spectrophotometry. Moreover, electrochemical studies reveal that the dinuclear complexes display a quasi-reversible redox behavior and a moderate electronic communication between the two metal centers in 8a. UV–vis studies show a remarkable absorption in the region （λmax = 300-700 nm） for these complexes.
