As a renewable biomass-based compound with wide applications in food additives,fine chemical synthesis and fuels,γ-valerolactone(GVL)has attached much attention.While,pyrrolidones are widely used in pharmaceutical,ag...As a renewable biomass-based compound with wide applications in food additives,fine chemical synthesis and fuels,γ-valerolactone(GVL)has attached much attention.While,pyrrolidones are widely used in pharmaceutical,agrochemical,material industrial and other chemical production.In this research,we demonstrated transformations of biomass-based ethyl levulinate(EL)into GVL and pyrrolidones by using heterogeneous catalysts(CNT-Ru-1)with N-heterocyclic carbene ruthenium(NHC-Ru)complex grafted on multi-walled carbon nanotube(CNT).The Ru catalyst showed high efficiency on EL hydrogenation to GVL with both EL conversion and GVL yield exceeding 99%.Moreover,the Ru catalyst readily promoted reductive amination of EL in the presence of various amines for pyrrolidone synthesis.Finally,the Ru catalyst was also applicable to hydrogenation of various carbonyl compounds for the synthesis of the corresponding alcohols with excellent catalytic performance.The research provides insight for heterogenizing the homogeneous noble metal-based catalysts with high catalytic active for biomass-based transformations.展开更多
A ruthenium carbene complex containing a Zn-porphyrin ligand has been developed. The complex was charac- terized by 1H NMR, IR, HRMS and elemental analysis. The catalytic activity of the ruthenium carbene complex for ...A ruthenium carbene complex containing a Zn-porphyrin ligand has been developed. The complex was charac- terized by 1H NMR, IR, HRMS and elemental analysis. The catalytic activity of the ruthenium carbene complex for olefin metathesis reactions was also investigated. The complex exhibited excellent performance for both ring-closing and cross metathesis reactions at 35 ℃.展开更多
A kinetic study of two ruthenium carbene catalysts, (PCy3)2Cl2Ru=CHPh 1 (Grubbs catalyst) and a new catalyst [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene](PPh3) (Cl)2Ru-CHPh 3, were conducted in...A kinetic study of two ruthenium carbene catalysts, (PCy3)2Cl2Ru=CHPh 1 (Grubbs catalyst) and a new catalyst [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene](PPh3) (Cl)2Ru-CHPh 3, were conducted in metathesis of 1-hexene. The kinetic behavior of these catalysts at 40, 50, 60 and 70℃ was compared. Complex 3 has the more active catalytic effect at temperatures 40-70℃.展开更多
A Grubbs-Hoveyda pre-catalyst having a trimeric resting state based on 2,4,6-trichloro-1,3,5-triazine was syn-thesized and the complex was characterized by NMR,HRMS and elemental analysis.The activity of this complex ...A Grubbs-Hoveyda pre-catalyst having a trimeric resting state based on 2,4,6-trichloro-1,3,5-triazine was syn-thesized and the complex was characterized by NMR,HRMS and elemental analysis.The activity of this complex for ring-closing metathesis(RCM)was investigated.The catalytic system possesses high catalytic activity for many different olefin substrates.展开更多
The reaction of a ruthenium carbide complex RuCl2(C:)(PCy3)2 with [H(Et2O)x]+[BF4]- at a molar ratio of 1:2 produced a two-core ruthenium carbene complex, {[RuCl(=CHPCy3)(PCy3)]2(μ-Cl)3}+·[BF4]-,...The reaction of a ruthenium carbide complex RuCl2(C:)(PCy3)2 with [H(Et2O)x]+[BF4]- at a molar ratio of 1:2 produced a two-core ruthenium carbene complex, {[RuCl(=CHPCy3)(PCy3)]2(μ-Cl)3}+·[BF4]-, in the form of a yellow-green crystalline solid in a yield of 94%. This two-core ruthenium complex is a selective catalyst for ring closing metathesis of unsubstituted terminal dienes. More importantly, no isomerized byproduct was observed for N-substrates when the two-core ruthenium complex was used as the catalyst at an elevated temperature(137 °C), indicating that the complex is a chemo-selective catalyst for ring closing metathesis reactions.展开更多
基金the financial support from the National Natural Science Foundation of China(U1810111,51872124 and21676116)Natural Science Foundation of Guangdong Province,China(2018B030311010)+1 种基金the Fundamental Research Funds for the Central Universities(21617431)Key Laboratory of Biomass Chemical Engineering of Ministry of Education,Zhejiang University(2018BCE002)
文摘As a renewable biomass-based compound with wide applications in food additives,fine chemical synthesis and fuels,γ-valerolactone(GVL)has attached much attention.While,pyrrolidones are widely used in pharmaceutical,agrochemical,material industrial and other chemical production.In this research,we demonstrated transformations of biomass-based ethyl levulinate(EL)into GVL and pyrrolidones by using heterogeneous catalysts(CNT-Ru-1)with N-heterocyclic carbene ruthenium(NHC-Ru)complex grafted on multi-walled carbon nanotube(CNT).The Ru catalyst showed high efficiency on EL hydrogenation to GVL with both EL conversion and GVL yield exceeding 99%.Moreover,the Ru catalyst readily promoted reductive amination of EL in the presence of various amines for pyrrolidone synthesis.Finally,the Ru catalyst was also applicable to hydrogenation of various carbonyl compounds for the synthesis of the corresponding alcohols with excellent catalytic performance.The research provides insight for heterogenizing the homogeneous noble metal-based catalysts with high catalytic active for biomass-based transformations.
基金This work was supported by the National Natural Science Foundation of China (grant No. 21102102).
文摘A ruthenium carbene complex containing a Zn-porphyrin ligand has been developed. The complex was charac- terized by 1H NMR, IR, HRMS and elemental analysis. The catalytic activity of the ruthenium carbene complex for olefin metathesis reactions was also investigated. The complex exhibited excellent performance for both ring-closing and cross metathesis reactions at 35 ℃.
文摘A kinetic study of two ruthenium carbene catalysts, (PCy3)2Cl2Ru=CHPh 1 (Grubbs catalyst) and a new catalyst [1,3-bis(2,6-dimethylphenyl)4,5-dihydroimidazol-2-ylidene](PPh3) (Cl)2Ru-CHPh 3, were conducted in metathesis of 1-hexene. The kinetic behavior of these catalysts at 40, 50, 60 and 70℃ was compared. Complex 3 has the more active catalytic effect at temperatures 40-70℃.
基金supports from NSFC(Nos.21102102,21072149,20872108)are gratefully acknowledged.
文摘A Grubbs-Hoveyda pre-catalyst having a trimeric resting state based on 2,4,6-trichloro-1,3,5-triazine was syn-thesized and the complex was characterized by NMR,HRMS and elemental analysis.The activity of this complex for ring-closing metathesis(RCM)was investigated.The catalytic system possesses high catalytic activity for many different olefin substrates.
基金Supported by the National Natural Science Foundation of China(No.20872108)
文摘The reaction of a ruthenium carbide complex RuCl2(C:)(PCy3)2 with [H(Et2O)x]+[BF4]- at a molar ratio of 1:2 produced a two-core ruthenium carbene complex, {[RuCl(=CHPCy3)(PCy3)]2(μ-Cl)3}+·[BF4]-, in the form of a yellow-green crystalline solid in a yield of 94%. This two-core ruthenium complex is a selective catalyst for ring closing metathesis of unsubstituted terminal dienes. More importantly, no isomerized byproduct was observed for N-substrates when the two-core ruthenium complex was used as the catalyst at an elevated temperature(137 °C), indicating that the complex is a chemo-selective catalyst for ring closing metathesis reactions.