Suzuki-Miyaura reactions, involving the activation of carbon-halogen bonds, especially C-C1 bonds, have drawn widespread attention because of their huge industrial potential. However, these reactions are dependent on ...Suzuki-Miyaura reactions, involving the activation of carbon-halogen bonds, especially C-C1 bonds, have drawn widespread attention because of their huge industrial potential. However, these reactions are dependent on the development of highly active and stable catalysts. Herein, we developed a convenient one-pot wet route to synthesize PdxCuy bimetallic nanocrystals for the Suzuki-Miyaura reaction. By introducing Cu, an earth-abundant element, the catalytic activity was greatly enhanced while the amount of Pd required was reduced. PdxCuy nanocrystals of different compositions, including PdBCu, Pd2Cu, PdCu, PdCu2, and PdCu3, were successfully synthesized by tuning the Pd：Cu ratio. Their catalytic performance in Suzuki-Miyaura reactions between phenylboronic acid and halobenzenes （iodo-, bromo-, or chlorobenzene） showed that PdCua nanocatalyst demonstrated the best efficacy.展开更多
The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting materials.It has been desired tofind a supporting material designed in molecular level to an...The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting materials.It has been desired tofind a supporting material designed in molecular level to anchor a single-atom catalyst and provide high degree of dispersion and substrate access in aqueous media.Here,we prepared discrete cages of metal-organic polyhedra anchoring single Pd atom(MOP-BPY(Pd))and successfully performed a Suzuki-Miyaura cross coupling reaction with various substrates in aqueous media.It was revealed that each tetrahedral cage of MOP-BPY(Pd)has 4.5 Pd atoms on average and retained its high degree of dispersion up to 3 months in water.The coupling efficiencies of the Suzuki-Miyaura cross coupling reaction exhibited more than 90.0%for various substrates we have tested in the aqueous media,which is superior to those of the molecular Pd complex and metal-organic framework(MOF)anchoring Pd atoms.Moreover,MOP-BPY(Pd)was successfully recovered and recycled without performance degradation.展开更多
We have successfully prepared a series of Pd- Ni/TiO2 catalysts by a one-step impregnation-reduction method. Among these catalysts with different compositions of Ni and Pd, the one with the Ni：Pd ratio of 2.95 showed...We have successfully prepared a series of Pd- Ni/TiO2 catalysts by a one-step impregnation-reduction method. Among these catalysts with different compositions of Ni and Pd, the one with the Ni：Pd ratio of 2.95 showed the best activity. Small monodispersed Pd-Ni bimetallic nanoparticles were loaded on the surface of titanium oxide nanopowder as confirmed with TEM and EDS mapping. The XPS analysis demonstrated that Pd exists as 31% Pd（II） species and 69% Pd（0） species and all nickel is Ni（II）. The prepared Pd-Ni/TiO2 exhibited enhanced catalytic activity compared to an equal amount of Pd/TiO2 for Suzuki-Miyaura reactions together with excellent applicability and reusability.展开更多
A variety of 4＇- and 3-C-aryl-quercetin derivatives were conveniently synthesized via Suzuki-Miyaura coupling of the corresponding quercetin-O-triflates with aryl boronic acids or boronates.
Suzuki-Miyaura reaction of aryl halides with phenylboronic acid using a heterogeneous palladium catalyst based on activated carbons(AC) was systematically investigated in this work. Two different reaction modes(batch ...Suzuki-Miyaura reaction of aryl halides with phenylboronic acid using a heterogeneous palladium catalyst based on activated carbons(AC) was systematically investigated in this work. Two different reaction modes(batch procedure and continuous-flow procedure) were used to study the variations of reaction processing. The heterogeneous catalysts presented excellent reactivity and recyclability for iodobenzene and bromobenzene substrates in batch mode, which can be attributed to stabilization of Pd nanoparticles by the thiol and amino groups on the AC supports. However, significant dehalogenation in the reaction mixture and Pd leaching from the heterogeneous catalysts were observed in continuous-flow mode.This unique phenomenon in continuous-flow mode resulted in a dramatic decline in reaction selectivity and durability of heterogeneous catalysts comparing with that of batch mode. In addition, the heterogeneous Pd catalysts with thiol-and amino-modified AC supports exhibited different reactivity and durability in batch and continuous-flow mode owing to the difference of interaction between Pd species and AC supports.展开更多
Topochemical polymerization of molecular crystals into porous materials is of significance due to their promising applications in the field of adsorption and catalysis,yet rarely reported due to the synthesis difficul...Topochemical polymerization of molecular crystals into porous materials is of significance due to their promising applications in the field of adsorption and catalysis,yet rarely reported due to the synthesis difficulty.Herein,a hydrogen-bonded organic framework(HOF-45)has been fabricated by the crystallization of a cage-like building block containing three alkynyl groups.It exhibits almost mesoporous structure demonstrated by single crystal X-ray diffraction study.Light-driven topochemical polymerization of HOF-45 with ethanedithiol covalently links alkynyl groups in HOF-45,generating a hydrogen-bond and covalentbond cross-linked material(HOF-45C).In contrast to HOF-45,cross-linked HOF-45C retains the crystalline nature and displays improved solution resistence according to the powder X-ray diffraction data.In particular,HOF-45C is able to support the growth of ultrafine palladium nanoparticles with the average size of ca.1.9 nm for rapidly promoting the degradation of nitrophenol,methyl orange,and congo red with the help of NaBH_(4)as well as Suzuki-Miyaura coupling reaction.This work inputs a new idea on the HOFs application in preparing covalent-linked porous organic materials.展开更多
Surface-enhanced Raman spectroscopy(SERS), a powerful surface vibrational spectroscopic technique, is ideally suited for in situ monitoring the chemical transformations occurred at surfaces and/or interfaces.For in si...Surface-enhanced Raman spectroscopy(SERS), a powerful surface vibrational spectroscopic technique, is ideally suited for in situ monitoring the chemical transformations occurred at surfaces and/or interfaces.For in situ SERS monitoring, a platform integrated both plasmonic and catalytic activity is a prerequisite. Here, we fabricate a bifunctional Au-Pd nanocoronal film for in situ SERS monitoring Suzuki-Miyaura cross-coupling reaction. This excellent bifunctional substrate leads to the coupling of high catalytic activity with a strong SERS effect at the center of two adjacent Au cores and shows fine reproducibility and stability of SERS signals. During investigating the Suzuki reaction with in situ SERS, we found two distinct catalytic kinetic processes resulted from two disparate catalytic sites on a Au-Pd nanocoronal. Comparing with conventional analytical techniques, this work provides a novel approach for studying Suzuki reactions at surfaces and/or interfaces with in situ SERS.展开更多
基金This research was supported in part by the National Natural Science Foundation of China （Nos. 21475007, 21275015 and 21505003）, and the Fundamental Research Funds for the Central Universities （Nos. YS1406, buctrc201507 and buctrc201608）. We also thank the support from the Innovation and Promotion Project of Beijing University of Chemical Technology, the Public Hatching Platform for Recruited Talents of Beijing University of Chemical Technology, the High- Level Faculty Program of Beijing University of Chemical Technology （No. buctrc201325）, and BUCT Fund for Disciplines Construction and Development （No. XK1526）.
文摘Suzuki-Miyaura reactions, involving the activation of carbon-halogen bonds, especially C-C1 bonds, have drawn widespread attention because of their huge industrial potential. However, these reactions are dependent on the development of highly active and stable catalysts. Herein, we developed a convenient one-pot wet route to synthesize PdxCuy bimetallic nanocrystals for the Suzuki-Miyaura reaction. By introducing Cu, an earth-abundant element, the catalytic activity was greatly enhanced while the amount of Pd required was reduced. PdxCuy nanocrystals of different compositions, including PdBCu, Pd2Cu, PdCu, PdCu2, and PdCu3, were successfully synthesized by tuning the Pd：Cu ratio. Their catalytic performance in Suzuki-Miyaura reactions between phenylboronic acid and halobenzenes （iodo-, bromo-, or chlorobenzene） showed that PdCua nanocatalyst demonstrated the best efficacy.
基金the Basic Science Research Program(No.NRF-2019R1A2C4069764)by Convergent Technology R&D Program for Hum an Augm entation(No.2019M3C1B8077549)through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT.
文摘The challenge for single-atom catalysts in various C-C cross coupling reaction exists in the development of solid supporting materials.It has been desired tofind a supporting material designed in molecular level to anchor a single-atom catalyst and provide high degree of dispersion and substrate access in aqueous media.Here,we prepared discrete cages of metal-organic polyhedra anchoring single Pd atom(MOP-BPY(Pd))and successfully performed a Suzuki-Miyaura cross coupling reaction with various substrates in aqueous media.It was revealed that each tetrahedral cage of MOP-BPY(Pd)has 4.5 Pd atoms on average and retained its high degree of dispersion up to 3 months in water.The coupling efficiencies of the Suzuki-Miyaura cross coupling reaction exhibited more than 90.0%for various substrates we have tested in the aqueous media,which is superior to those of the molecular Pd complex and metal-organic framework(MOF)anchoring Pd atoms.Moreover,MOP-BPY(Pd)was successfully recovered and recycled without performance degradation.
基金Acknowledgements We are grateful for financial support from the National Key R＆D Program of China （Grant No. 2016YFA0202900）, the National Natural Science Foundation of China （Grant Nos. 21376212 and 21436010）.
文摘We have successfully prepared a series of Pd- Ni/TiO2 catalysts by a one-step impregnation-reduction method. Among these catalysts with different compositions of Ni and Pd, the one with the Ni：Pd ratio of 2.95 showed the best activity. Small monodispersed Pd-Ni bimetallic nanoparticles were loaded on the surface of titanium oxide nanopowder as confirmed with TEM and EDS mapping. The XPS analysis demonstrated that Pd exists as 31% Pd（II） species and 69% Pd（0） species and all nickel is Ni（II）. The prepared Pd-Ni/TiO2 exhibited enhanced catalytic activity compared to an equal amount of Pd/TiO2 for Suzuki-Miyaura reactions together with excellent applicability and reusability.
文摘A variety of 4＇- and 3-C-aryl-quercetin derivatives were conveniently synthesized via Suzuki-Miyaura coupling of the corresponding quercetin-O-triflates with aryl boronic acids or boronates.
基金the support of the National Natural Science Foundation of China (20222809, 21978146)TsinghuaFoshan Innovation Special Fund (2021THFS0214)。
文摘Suzuki-Miyaura reaction of aryl halides with phenylboronic acid using a heterogeneous palladium catalyst based on activated carbons(AC) was systematically investigated in this work. Two different reaction modes(batch procedure and continuous-flow procedure) were used to study the variations of reaction processing. The heterogeneous catalysts presented excellent reactivity and recyclability for iodobenzene and bromobenzene substrates in batch mode, which can be attributed to stabilization of Pd nanoparticles by the thiol and amino groups on the AC supports. However, significant dehalogenation in the reaction mixture and Pd leaching from the heterogeneous catalysts were observed in continuous-flow mode.This unique phenomenon in continuous-flow mode resulted in a dramatic decline in reaction selectivity and durability of heterogeneous catalysts comparing with that of batch mode. In addition, the heterogeneous Pd catalysts with thiol-and amino-modified AC supports exhibited different reactivity and durability in batch and continuous-flow mode owing to the difference of interaction between Pd species and AC supports.
基金supported by the Natural Science Foundation of China(22235001,22175020,22131005,22011540002,21631003)the Xiaomi Young Scholar Program+1 种基金the Fundamental Research Funds for the Central UniversitiesUniversity of Science and Technology Beijing
文摘Topochemical polymerization of molecular crystals into porous materials is of significance due to their promising applications in the field of adsorption and catalysis,yet rarely reported due to the synthesis difficulty.Herein,a hydrogen-bonded organic framework(HOF-45)has been fabricated by the crystallization of a cage-like building block containing three alkynyl groups.It exhibits almost mesoporous structure demonstrated by single crystal X-ray diffraction study.Light-driven topochemical polymerization of HOF-45 with ethanedithiol covalently links alkynyl groups in HOF-45,generating a hydrogen-bond and covalentbond cross-linked material(HOF-45C).In contrast to HOF-45,cross-linked HOF-45C retains the crystalline nature and displays improved solution resistence according to the powder X-ray diffraction data.In particular,HOF-45C is able to support the growth of ultrafine palladium nanoparticles with the average size of ca.1.9 nm for rapidly promoting the degradation of nitrophenol,methyl orange,and congo red with the help of NaBH_(4)as well as Suzuki-Miyaura coupling reaction.This work inputs a new idea on the HOFs application in preparing covalent-linked porous organic materials.
基金the financial support from the National Natural Science Foundation of China (No. 22022406)the Natural Science Foundation of Tianjin (Nos. 20JCJQJC00110 and 20JCYBJC00590)+1 种基金the 111 project (No. B12015)the Haihe Laboratory of Sustainable Chemical Transformations。
文摘Surface-enhanced Raman spectroscopy(SERS), a powerful surface vibrational spectroscopic technique, is ideally suited for in situ monitoring the chemical transformations occurred at surfaces and/or interfaces.For in situ SERS monitoring, a platform integrated both plasmonic and catalytic activity is a prerequisite. Here, we fabricate a bifunctional Au-Pd nanocoronal film for in situ SERS monitoring Suzuki-Miyaura cross-coupling reaction. This excellent bifunctional substrate leads to the coupling of high catalytic activity with a strong SERS effect at the center of two adjacent Au cores and shows fine reproducibility and stability of SERS signals. During investigating the Suzuki reaction with in situ SERS, we found two distinct catalytic kinetic processes resulted from two disparate catalytic sites on a Au-Pd nanocoronal. Comparing with conventional analytical techniques, this work provides a novel approach for studying Suzuki reactions at surfaces and/or interfaces with in situ SERS.
