The palladium(Pd)-catalyzed Suzuki reaction is widely applied in the pharmaceutical industry,where constructing highly active and low-cost Pd sites are impendent.Here,we report the fabrication of a heterogeneous Pd/Ti...The palladium(Pd)-catalyzed Suzuki reaction is widely applied in the pharmaceutical industry,where constructing highly active and low-cost Pd sites are impendent.Here,we report the fabrication of a heterogeneous Pd/Tio2 catalyst via engineering of an electronic structure of a single Pd_(1)atom on monolayered Ti_(0.87)O_(2)nanosheet(Pd_(1)-Ti_(0.87)O_(2)).This catalyst motivated the kinetically sluggish C-Br cleavage,thus boosting the Suzuki reaction at room temperature.Pd_(1)-Ti_(0.87)O_(2)exhibited an outstanding activity with turnover frequency(TOF)of 11,110 h-1,exceeding that of PdCl_(2)and Pd(OAc)_(2)catalysts by a factor of>200.Various in situ techniques were employed to investigate the C-Br activation process,which showed that Pd_(1)kinetic-feasibly dissociated the chemisorbed bromobenzene,especially the C-Br bond cleavage.Theoretical calculations further revealed that the improved activity is ascribed to the optimized charge state of Pd_(1)within the Pd_(1)O4 realm via charge transfer.展开更多
The C-Br bond of 2-bromothiophene was successfully cleavaged by tetrakis（trime-thylphosphine）cobalt（0）. Penta-coordinate cobalt（Ⅱ） bromide complex 1 （α-C4H3S）CoBr（PMe3）3 as C-Br bond activation product was...The C-Br bond of 2-bromothiophene was successfully cleavaged by tetrakis（trime-thylphosphine）cobalt（0）. Penta-coordinate cobalt（Ⅱ） bromide complex 1 （α-C4H3S）CoBr（PMe3）3 as C-Br bond activation product was obtained. The molecular and crystal structures of complex 1 were determined by single-crystal X-ray diffraction. Complex 1 belongs to the orthorhombic crystal system, space group Pnma with α = 20.428（4）, b =11.036（2）, c = 9.201（2） A, V= 2074.3（7） A^3, Z = 4, Dc = 1.442 g/cm^3,μ = 0.401 mm^-1, F（000） = 924 and T = 273 K. Complex 1 was also characterized by elemental analysis, IR, UV-Vis, photoluminescence （PL） spectroscopy and TGA.展开更多
基金This study was supported financially by the National Natural Science Foundation of China(grant nos.91961125,21905019,and 21903001)the Fundamental Research Funds for the Central Universities(grant nos.2018JBZ107 and 2019RC035)+2 种基金the Ministry of Science and Technology of China(grant no.2018YFE0124600)the Chemistry and Chemical Engineering Guangdong Laboratory(grant no.1932004)the Natural Science Foundation of Anhui Province(grant no.1908085QB58)。
文摘The palladium(Pd)-catalyzed Suzuki reaction is widely applied in the pharmaceutical industry,where constructing highly active and low-cost Pd sites are impendent.Here,we report the fabrication of a heterogeneous Pd/Tio2 catalyst via engineering of an electronic structure of a single Pd_(1)atom on monolayered Ti_(0.87)O_(2)nanosheet(Pd_(1)-Ti_(0.87)O_(2)).This catalyst motivated the kinetically sluggish C-Br cleavage,thus boosting the Suzuki reaction at room temperature.Pd_(1)-Ti_(0.87)O_(2)exhibited an outstanding activity with turnover frequency(TOF)of 11,110 h-1,exceeding that of PdCl_(2)and Pd(OAc)_(2)catalysts by a factor of>200.Various in situ techniques were employed to investigate the C-Br activation process,which showed that Pd_(1)kinetic-feasibly dissociated the chemisorbed bromobenzene,especially the C-Br bond cleavage.Theoretical calculations further revealed that the improved activity is ascribed to the optimized charge state of Pd_(1)within the Pd_(1)O4 realm via charge transfer.
基金supported by Shandong Development Plan of Science and Technology (2011GGX10203)
文摘The C-Br bond of 2-bromothiophene was successfully cleavaged by tetrakis（trime-thylphosphine）cobalt（0）. Penta-coordinate cobalt（Ⅱ） bromide complex 1 （α-C4H3S）CoBr（PMe3）3 as C-Br bond activation product was obtained. The molecular and crystal structures of complex 1 were determined by single-crystal X-ray diffraction. Complex 1 belongs to the orthorhombic crystal system, space group Pnma with α = 20.428（4）, b =11.036（2）, c = 9.201（2） A, V= 2074.3（7） A^3, Z = 4, Dc = 1.442 g/cm^3,μ = 0.401 mm^-1, F（000） = 924 and T = 273 K. Complex 1 was also characterized by elemental analysis, IR, UV-Vis, photoluminescence （PL） spectroscopy and TGA.
