Synthesis of mesoporous SiO₂–CeO₂ hybrid nanostructures with high catalytic activity for transamidation reaction

Abstract

Mechanism of transamidation reaction between acetamide and N-heptyl amine to yield N-heptyl acetamide, catalyzed by mesoporous SiO2–CeO2 hybrid nanostructures.

Transamidation of secondary carboxamides and amidation of esters are facilitated by magnetic Co@NC nanoparticles, as a highly efficient and recyclable catalyst under neat conditions

“…25–27 In the last few decades, nanoparticles as catalysts have garnered considerable interest because of their enhanced selectivity and strong catalytic activity in organic reactions. 28–30 Recently, a variety of new nano-catalysts, designed specifically for the transamidation of amides, have been developed, such as Fe(OH) 3 @Fe 3 O 4 nanoparticles, 31 guanidine acetic acid (GAA) nanoparticles, 32 magnetically separable Fe 3 O 4 nanoparticles, 33 mesoporous silica nanoparticles (MSNs), 34 a sulfated poly borate nanocatalyst, 35 an Fe 3 O 4 –OSO 3 H nanocatalyst, 36 a SiO 2 –CeO 2 hybrid nanocomposite, 37 and nanosized zeolite beta (MSNs) 38 are used for primary amides and citric acid-coated nanoparticles (Fe 3 O 4 –CA NPs) for transamidation of primary and secondary amides. 39 Despite their numerous advantages, all these nanoparticle-catalyzed transamidation reactions involving unactivated amides require high temperatures and longer time.…”

Molecular Oxygen‐Induced Transamidation of Unactivated Amides in Diethyl Carbonate in the Presence of a Palladium Catalyst

“…Stoichiometric amounts of AlCl 3 , [13] N,N-carbonyldiimidazole, [14] boric acid, [12d] potassium tert-butoxide, [15] borate esters, [16] and LiHMDS [12f] can promote the reaction, and in addition to biocatalytic transamidations in the presence of enzymes, [17] several procedures involving an in-situ activation of the starting amide, [18] those based on ionic liquid catalysts [19] and even a catalyst-free procedure [20] have been reported. Moreover, the use of catalytic amounts (5-50 mol%) of bisacetoxyiodobenzene, [21] povidone iodine, [22] hydroxylamine hydrochloride, [23] benzoic acid, [24] L-proline,, [25] chitosan, [26] benzotriazole, [27] SiO 2 À H 2 SO 4 and strongly acidic mesoporous silica, [28] H-β-zeolite [29] and alumina, [30] inter alia, [31] have been also described in the field of transition metal-free catalysis. In this regard, a triflic acid-iodide co-catalyzed transamidation of unactivated tertiary amides based on an amide re-routing through reactive acyl iodide intermediates has recently been published.…”