A novel and efficient method for distinguishing between chiral diols and diphenols has been established through the use of^(19)F NMR spectroscopy.Central to this system's efficacy is a chiral amine,strategically m...A novel and efficient method for distinguishing between chiral diols and diphenols has been established through the use of^(19)F NMR spectroscopy.Central to this system's efficacy is a chiral amine,strategically modified with a CF_(3)group.This amine reacts in-situ with 2-formylphenylboronic acid to create a chiral^(19)F-labeled probe.This probe demonstrates discriminatory capabilities by interacting with hydroxy-containing analytes to form boronic esters.These esters produce distinct^(19)F NMR signals that vary according to their stereoconfiguration,facilitating accurate chiral differentiation.The method's resolution capacity was demonstrated by successfully identifying 12 distinct chiral analytes(six pairs of enantiomers)in complex mixtures,highlighting its extensive potential in diverse chiral analysis applications.展开更多
Summary of main observation and conclusion Poly(p-xylylene)s(PPX)have found wide applications in various fields owing to their chemical robustness,low gas permeability and excellent dielectric properties.As a structur...Summary of main observation and conclusion Poly(p-xylylene)s(PPX)have found wide applications in various fields owing to their chemical robustness,low gas permeability and excellent dielectric properties.As a structural isomer of PPX,poly(o-xylylene)s(POX),possessing a distinct main-chain connectivity,are excellent candidates to pursue high-performance.materials;however,the investigation of POX is hampered by the.lack of efficient synthetic methods.Herein,we report a straightforward way to access POXs through a cobalt-catalyzed reductive polymerization.This method not only allows the direct preparation of electronically unmodified POXs,but also enables the copolymerization between o-xylylene dibromides bearing different aryl or benzylic substituents.The glass transition temperatures of the copolymers can be finely tuned by varying the ratio between comonomers.The obtained POXs are solvent processible and amenable for thin-film fabrication.As aryl bromide moiety remains untouched during the polymerization,post-polymerization functionalization is easily achieved through Suzuki-Miyaura coupling reaction.The chemistry also enables the copolymerization of xylylene dibromide regioisomers,thereby leading to diversified non-conjugated polymers,whose backbones are rich in arylene moieties.Moreover,the use of the polymerization strategy to synthesize structurally novel porous polymers is demonstrated.展开更多
基金supported by the National Key Research and Development Program(2021YFF0701700)the National Natural Science Foundation of China(22271305).
文摘A novel and efficient method for distinguishing between chiral diols and diphenols has been established through the use of^(19)F NMR spectroscopy.Central to this system's efficacy is a chiral amine,strategically modified with a CF_(3)group.This amine reacts in-situ with 2-formylphenylboronic acid to create a chiral^(19)F-labeled probe.This probe demonstrates discriminatory capabilities by interacting with hydroxy-containing analytes to form boronic esters.These esters produce distinct^(19)F NMR signals that vary according to their stereoconfiguration,facilitating accurate chiral differentiation.The method's resolution capacity was demonstrated by successfully identifying 12 distinct chiral analytes(six pairs of enantiomers)in complex mixtures,highlighting its extensive potential in diverse chiral analysis applications.
基金This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDC06020102)the National Natural Science Foundation of China(21871291,91956120,21421002)。
文摘Summary of main observation and conclusion Poly(p-xylylene)s(PPX)have found wide applications in various fields owing to their chemical robustness,low gas permeability and excellent dielectric properties.As a structural isomer of PPX,poly(o-xylylene)s(POX),possessing a distinct main-chain connectivity,are excellent candidates to pursue high-performance.materials;however,the investigation of POX is hampered by the.lack of efficient synthetic methods.Herein,we report a straightforward way to access POXs through a cobalt-catalyzed reductive polymerization.This method not only allows the direct preparation of electronically unmodified POXs,but also enables the copolymerization between o-xylylene dibromides bearing different aryl or benzylic substituents.The glass transition temperatures of the copolymers can be finely tuned by varying the ratio between comonomers.The obtained POXs are solvent processible and amenable for thin-film fabrication.As aryl bromide moiety remains untouched during the polymerization,post-polymerization functionalization is easily achieved through Suzuki-Miyaura coupling reaction.The chemistry also enables the copolymerization of xylylene dibromide regioisomers,thereby leading to diversified non-conjugated polymers,whose backbones are rich in arylene moieties.Moreover,the use of the polymerization strategy to synthesize structurally novel porous polymers is demonstrated.
