Conversion of levulinic acid to N-substituted pyrrolidinones over a nonnoble bimetallic catalyst Cu15Pr3/Al2O3

Sustainable access to renewable N-containing chemicals from reductive amination of biomass-derived platform compounds

“…Subsequently, the [118], Pt/TiO 2 -NTs [119] and Pt/P-TiO 2 [120]) for the reductive amination of LA or its esters (entries 5-7, (AuPd alloy nanoparticles with a Pd content of 34 mol%) was highly active for the reductive amination of ethyl levulinate with n-octylamine (entry 11, Table 6) [124]. [127] was also exploited for the reductive amination of LA with n-octylamine, and resulted in remarkable results but under relatively harsh conditions (175 °C) (entry 14, Table 6).…”

Cycloamination strategies for renewable N-heterocycles

“…[114][115][116][117][118][119][120] Apart from LA (22a) and primary amines, carbohydrates (e.g., glucose) and nitro compounds can be employed as the precursor of LA (22a) and nitrogen sources for producing pyrrolidones via additional acid-catalyzed hydrolysis and in situ hydrogenation steps, respectively. 121,122 The replacement of precious elements in Scheme 8 with abundant and low-cost metals is highly desirable, for which several well-designed base metal catalysts, such as Cu 15 /Al 2 O 3 doped with Pr (Cu 15 Pr 3 /Al 2 O 3 ), 123 carbon-supported FeNi nanoparticles, 124 and carbon nanotubes supported porous-carbon-coated Ni (CNF x @Ni@CNTs) 125 have been explored for synthesis of N-substituted pyrrolidones (up to 99% yield) from LA (22a) and amines although they require relatively harsh reaction conditions (130°C to 175°C, 1 to 5 MPa H 2 ). Well dispersed metal particles (e.g., Cu and Ni) on porous solid supports (e.g., γ-Al 2 O 3 , carbon nanotubes) and the use of continuous fixed-bed reactors enhance catalytic performance of prepared non-noble metals.…”

“…Well dispersed metal particles (e.g., Cu and Ni) on porous solid supports (e.g., γ-Al 2 O 3 , carbon nanotubes) and the use of continuous fixed-bed reactors enhance catalytic performance of prepared non-noble metals. [123][124][125] Solid supports not only increase metal stability and improve reusability, but also provide acid sites with appropriate acid strength and density that enhances substrate adsorption onto active sites of the catalyst that facilitates tandem condensation and hydrogenation processes.…”

Effect of Phosphorus Precursor, Reduction Temperature, and Support on the Catalytic Properties of Nickel Phosphide Catalysts in Continuous-Flow Reductive Amination of Ethyl Levulinate

“…Reductive amination of LA or levulinates with primary amines over heterogeneous metal catalysts using molecular hydrogen as a reducing agent is a promising method for the synthesis of N-substituted-5-methyl-2-pyrrolidones [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], which are an alternative to the carcinogenic solvent N-methyl-2-pyrrolidone (NMP) used in large volumes in industry [3]. Due to the high cost and limited availability of precious metals, the use of non-noble metal catalysts is of particular interest [1,[20][21][22][23][24][25].…”

“…A positive role of acid sites on the surface of the support material in achieving a high pyrrolidone yield was observed, which is associated with the acceleration of EL amination and cyclization steps [9][10][11][12][13][14]21,25]. Nickel phosphides are attracting increased attention as bifunctional catalysts due to the presence of both metal and acid sites [26][27][28].…”