Aerobic Oxidation of Cyclic Amines to Lactams Catalyzed by Ceria-Supported Nanogold

作者：Dairo Taiwo O; Nelson Nicholas C; Slowing Igor I; Angelici Robert J; Woo L Keith

来源：Catalysis Letters, 2016, 146(11): 2278-2291.

DOI：10.1007/s10562-016-1834-2

• Lactams
• Nanogold
• Ceria
• Cyclic amines
• Oxidation
• Amine oxidation

The oxidative transformation of cyclic amines to lactams, which are important chemical feedstocks, is efficiently catalyzed by CeO2-supported gold nanoparticles (Au/CeO2) and Aerosil 200 in the presence of an atmosphere of O-2. The complete conversion of pyrrolidine was achieved in 6.5 h at 160 A degrees C, affording a 97 % yield of the lactam product 2-pyrrolidone (gamma-butyrolactam), while 2-piperidone (delta-valerolactam) was synthesized from piperidine (83 % yield) in 2.5 h. Caprolactam, the precursor to the commercially important nylon-6, was obtained from hexamethyleneimine in 37 % yield in 3 h. During the oxidation of pyrrolidine, two transient species, 5-(pyrrolidin-1-yl)-3,4-dihydro-2H-pyrrole (amidine-5) and 4-amino-1-(pyrrolidin-1-yl)butan-1-one, were observed. Both of these compounds were oxidized to 2-pyrrolidone under catalytic conditions, indicating their role as intermediates in the reaction pathway. In addition to the reactions of cyclic secondary amines, Au/CeO2 also efficiently catalyzes the oxidation of N-methyl cyclic tertiary amines to the corresponding lactams at 80 and 100 A degrees C.

• 出版日期2016-11