The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aro...The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aromatic ketones, giving the corresponding optically active alcohols with high activities（up to 99% conversion） and excellent enantioselectivities（up to 96% e.e.） under mild conditions. The chiral ruthenium（Ⅱ） complex （R,R）-3 has been prepared and characterized by NMR and X-ray crystallography.展开更多
Hydrogen(H_(2))production by the aqueous-phase reforming of liquid organic hydrogen carriers such as methanol,ethanol,and formic acid has attracted much interest recently as it offers a safe and convenient means of pr...Hydrogen(H_(2))production by the aqueous-phase reforming of liquid organic hydrogen carriers such as methanol,ethanol,and formic acid has attracted much interest recently as it offers a safe and convenient means of producing H_(2)on demand by mitigating the costs and safety challenges associated with the storage and transportation of H_(2).Using efficient catalysts operative under easily achievable conditions is the key to the success of such reactions.展开更多
The kinetics of the hydrolysis of p-nitrophenyl picolinate(PNPP) catalyzed by zinc complex of schiff base macrocyclic polyamine(Zn2+ complex of 1,4,7,10,13,16-hexaazacyclooctadeca-1,3,10,12-tetraene was abbreviated to...The kinetics of the hydrolysis of p-nitrophenyl picolinate(PNPP) catalyzed by zinc complex of schiff base macrocyclic polyamine(Zn2+ complex of 1,4,7,10,13,16-hexaazacyclooctadeca-1,3,10,12-tetraene was abbreviated to ZnL2+)were studied at 25℃and pH=7.00.The pseudo-first-order rate constant(kψ)of the catalytic PNPP hydrolysis was 8.85×10-3 s-1,which was 463 times larger than that of the spontaneous hydrolysis of PNPP at pH=7.00.The effect of surfactants(Brij35,CTAB,and SDS),pH,temperature,and the concentration of ZnL2+ on the PNPP hydrolysis catalyzed by ZnL2+ was also studied in present paper.The thermodynamic and kinetic parameters of the titled reaction were obtained with the mathematical model.The activated water molecule in the reactant-catalyst complex was a strongly nucleophilic species,which could promote the PNNP hydrolysis reaction effectively.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.2042300220703034)+1 种基金the Natural Science Foundation of Fujian Province of China(No.2008J0235)the Natural Science Foundation of Guangxi Province of China(No. 0991016)
文摘The efficient catalytic systems generated in situ from RuCl2（PPh3）3 and chiral ligands N,N-bis[2-（di-o-tolylphosphino）-benzyl]cyclohexane-1,2-diamine（2） were employed for asymmetric transfer hydrogenation of aromatic ketones, giving the corresponding optically active alcohols with high activities（up to 99% conversion） and excellent enantioselectivities（up to 96% e.e.） under mild conditions. The chiral ruthenium（Ⅱ） complex （R,R）-3 has been prepared and characterized by NMR and X-ray crystallography.
基金support by the National Natural Science Foundation of China(no.21971106 and 22101117)GuangDong Basic and Applied Basic Research Foundation(2020A1515110990)+5 种基金the Stable Support Plan Program of Shenzhen Natural Science Fund(20200925161141006)the Jilin Provincial Science Research Foundation of China(no.20200403154SF)the Start-Up Fund from SUSTech(Y01216127 and Y01216227,ZZ)the Distinguished Expert Fund from Nanshan District of Shenzhen(K19219502,ZZ)are acknowledgedsponsored by the Guangdong Provincial Key Laboratory of Catalysis(no.2020B121201002)the Shenzhen Nobel Prize Scientists Laboratory Project(Shenzhen Grubbs Institute,C17783101).
文摘Hydrogen(H_(2))production by the aqueous-phase reforming of liquid organic hydrogen carriers such as methanol,ethanol,and formic acid has attracted much interest recently as it offers a safe and convenient means of producing H_(2)on demand by mitigating the costs and safety challenges associated with the storage and transportation of H_(2).Using efficient catalysts operative under easily achievable conditions is the key to the success of such reactions.
文摘The kinetics of the hydrolysis of p-nitrophenyl picolinate(PNPP) catalyzed by zinc complex of schiff base macrocyclic polyamine(Zn2+ complex of 1,4,7,10,13,16-hexaazacyclooctadeca-1,3,10,12-tetraene was abbreviated to ZnL2+)were studied at 25℃and pH=7.00.The pseudo-first-order rate constant(kψ)of the catalytic PNPP hydrolysis was 8.85×10-3 s-1,which was 463 times larger than that of the spontaneous hydrolysis of PNPP at pH=7.00.The effect of surfactants(Brij35,CTAB,and SDS),pH,temperature,and the concentration of ZnL2+ on the PNPP hydrolysis catalyzed by ZnL2+ was also studied in present paper.The thermodynamic and kinetic parameters of the titled reaction were obtained with the mathematical model.The activated water molecule in the reactant-catalyst complex was a strongly nucleophilic species,which could promote the PNNP hydrolysis reaction effectively.
