With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established...With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established,featuring readily available starting materials,high efficiency,good functional groups compatibility,green chemistry with high atom economy and only water release,etc.,to provide a series of polyfunctionalized 5-alkenyl-3-carbonylfurans,which could be applied to the late-stage functionalization of naturally occurring compounds and bioactive molecules,as well as the transformation to pyrroles and polycyclic aromatic hydrocarbon via electrocyclic reaction.Theγ-hydroxyl has played an important role in the unexpected process of ring opening isomerization of 2H-pyran to furanones,as confirmed by detailed mechanistic studies.展开更多
We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the di...We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the direct coupling method yield high optical intensity at resonance, which is different from the conventional strategy to create localized ＂hot spots.＂ The observed excitation efficiency of the Raman signal is significantly enhanced,owing to the high Q factor of the resonant cavity. Furthermore, effective modulation of the Raman intensity is available by adjusting the polymethyl methacrylate（PMMA） thickness in the guiding layer, i.e., by tuning the light–matter interaction length. A large modulation depth is verified through the fact that 10 times variation in the enhancement factor is observed in the experiment as the PMMA thickness varies from 7 to 23 μm.展开更多
基金Financial support from National Natural Science Foundation of China(Grant No.22201187)the starting grant from Capital Medical University(Grant No.3100-12400123)。
文摘With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established,featuring readily available starting materials,high efficiency,good functional groups compatibility,green chemistry with high atom economy and only water release,etc.,to provide a series of polyfunctionalized 5-alkenyl-3-carbonylfurans,which could be applied to the late-stage functionalization of naturally occurring compounds and bioactive molecules,as well as the transformation to pyrroles and polycyclic aromatic hydrocarbon via electrocyclic reaction.Theγ-hydroxyl has played an important role in the unexpected process of ring opening isomerization of 2H-pyran to furanones,as confirmed by detailed mechanistic studies.
基金supported by the Natural Science Foundation of Jiangsu Province(Nos.BK20140246 and BK20160417)the National Natural Science Foundation of China(No.61371057,61601251,11404092,and61701261)+1 种基金the China Postdoctoral Science Foundation Funded Project(No.2016M601586)the Fundamental Research Funds for the Central Universities(No.2017B14914)
文摘We report experimental realization of Raman spectra enhancement of copper phthalocyanine, using an on-chip metallic planar waveguide of the sub-millimeter scale. The oscillating ultrahigh order modes excited by the direct coupling method yield high optical intensity at resonance, which is different from the conventional strategy to create localized ＂hot spots.＂ The observed excitation efficiency of the Raman signal is significantly enhanced,owing to the high Q factor of the resonant cavity. Furthermore, effective modulation of the Raman intensity is available by adjusting the polymethyl methacrylate（PMMA） thickness in the guiding layer, i.e., by tuning the light–matter interaction length. A large modulation depth is verified through the fact that 10 times variation in the enhancement factor is observed in the experiment as the PMMA thickness varies from 7 to 23 μm.
