Mesoporous silica MCM-41 as a highly active, recoverable and reusable catalyst for direct amidation of fatty acids and long-chain amines

Catalytic amide formation from non-activated carboxylic acids and amines

“…Another mesoporous silica, MCM-41, was shown by Komura 90 et al to be an efficient catalyst for the amidation of fatty acids and long-chain aliphatic amines. 150 In the coupling of palmitic acid and n-hexylamine in refluxing toluene, 20 mol% of the MCM-41 catalyst furnished the product in 94% yield after 6 hours using a Dean-Stark apparatus. Seventeen additional 95 examples of amide products were presented with yields of 85 ->99% for primary unhindered amines, whereas more sterically hindered amines (tert-butylamide, N,N-dihexylamine and cyclohexylamine) gave rise to considerably lower yields with palmitic acid (0, 3 and 59%, respectively).…”

Acid functionalized carbon–silica composite and its application for solketal production

“…In addition to the SCS materials, the study also focus on the synthesis of hierarchical mesoporous silica (HMS) exhibiting a range of porosity properties tuneable for the desired applications such as organic mass transformations, adsorption of gases and immobilization of different organic moieties and inorganic metals [33][34][35], by varying the glucose concentration in the initial synthetic mixture followed by the simple calcination of the SCS composite materials.…”

Activity patterns of metal oxide catalysts in the synthesis of N-phenylpropionamide from propanoic acid and aniline

“…2 All such methods suffer from severe environmental, safety, and economic drawbacks, including the use of noxious and/or dangerous reagents, and multiple reaction-purification steps resulting in a poor atom economy, while large amounts of harmful waste, requiring special disposal treatments, contribute to high E-factors. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Apart from the recognized effectiveness of microwave irradiation on the condensation of carboxylic acids with amines, 4,6 and some catalytic redox routes using alternative reagents, 5,8,9,16 the most attractive option for amide bond formation is the heterogeneous catalytic condensation of amines with carboxylic acids. 2 On this account, the synthesis of amides has been recently indicated as a major green chemistry issue.…”

“…1,2 An alternative method involves the condensation of carboxylic acids with amines at high temperatures (>453 K), but is unfeasible for many functionalized substrates. [10][11][12][13][14][15] Many solid acids such as boron-organic compounds, 7 Fe 3+ /K10 montmorillonite, 10 FeCl 3 , ZnCl 2 , zeolites, and silica-based catalysts, 11 sulphatedtungstate, 12 MCM-41, 13 and Zr-salts, 14 were shown to be active in the synthesis of amides using toluene under "azeotropic distillation" reflux conditions (383 K), [1][2][3][4][5][6][7][8][9][10][11][12][13][14] while CeO 2 showed the highest activity among many oxides in various transamidation reactions. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Apart from the recognized effectiveness of microwave irradiation on the condensation of carboxylic acids with amines, 4,…”