Sulphuric acid immobilized on silica gel (H₂SO₄–SiO₂) as an eco-friendly catalyst for transamidation

Abstract

A novel method of transamidation of carboxamides with amines using catalytic amounts of H2SO4–SiO2 under solvent-free conditions has been developed. The scope of the methodology has been demonstrated with primary and secondary amines.

Organophosphoric Acid Promoted Transamidation: Using N,N‐Dimethylformamide and N,N‐Dimethylacetamide as the Acyl Sources

“…The result obviously showed the interaction between (BnO) 2 PO(OH) and DMF. Based on the above results and previous reports, [24] a plausible mechanism for the transamidation is presented in Scheme 3. Firstly, the amide bond of DMF was activated and protonated by (BnO) 2 PO(OH), and the intermediate A formed.…”

Nickel-(II)-Catalyzed N-Formylation and N-Acylation of Amines

“…Several metals and metal complexes have been reported for reaction reactions, such as copper, Fe­(III), [Pd­(OAc) 2 ], ZnCl 2 and other Lewis acids, ZnO, carbon nanotube–gold nanohybrid (Au–CNT), indium, nanocerium oxide, K 3 PO 4 , heteropolyanion-based ionic liquids (HPAILS), o -aryl oxide– N -heterocyclic carbene ruthenium­(II) ([Ru–NHC] complex), molybdate sulfuric acid, H 2 SO 4 SiO 2 , sulfated tungstate catalyst, and many others . However, a number of these methods suffer from drawbacks such as the use of expensive toxic formylating agents, use of costly catalysts, formation of byproducts, and critical workup processes, and a few of them are time-consuming.…”

Nickel(II)- and Silver(I)-Catalyzed C–H Bond Halogenation of Anilides and Carbamates

“…During the optimization study we found that when silver acetate was used instead of NiCl 2 •6H 2 O, as the catalyst in the presence of MSA in toluene at 50 °C, the desired product was obtained in 53% yield (entry 16). We then optimized the reaction conditions further by using silver-based catalysts, and competitive results were obtained with 10 mol% of Ag 2 CO 3 in the presence of 3.0 equivalent of MSA (entries [16][17][18][19][20][21][22][23][24][25][26][27]. Unfortunately, the reaction was not successful in water as the solvent (see the Supporting Information for details).…”