A new and green synthesis of formamidines by γ-Fe2O3@SiO2–HBF4 nanoparticles as a robust and magnetically recoverable catalyst

Introduction of Two New Brønsted Acidic Ionic Liquids for the Formamide and Formamidine Derivatization of Amines

“…In recent decades, N, N'-diaryl formamidines and their anions have been widely used in various fields of organic and medicinal chemistry. [18][19][20][21] These types of compounds have many biological and pharmaceutical properties, including antimalarial, [22] anesthetic, [23] ultraviolet light absorbent, [24] antihypertensive, [25] and renal dipeptidase inhibitory [26] activities.…”

Periodic Mesoporous Organosilica Containing Bridged N‐Sulfonic Acid Groups: Promotion of the Synthesis of N,N’‐Diarylformamidines, Benzoxazoles, Benzothiazoles and Benzimidazoles

“…these types of compounds, as important intermediates, are able to act as a protecting groups for primary amines, building blocks in polymer synthesis, bleaching agents for paper, chelating/bridging bonding modes via coordination with metal center and are useful as support linkers in solid phase synthesis . Different strategies have been reported in the literature for the synthesis of amidine containing materials including the reduction of carbodiimides with sodium borohydride in iso‐propanol, use of solvents like acetic acid under thermal conditions and use of promotors such as sulfated zirconia, hexafluoroisopropanol (HFIP) and γ‐Fe 2 O 3 @SiO 2 –HBF 4 …”

“…[7] Different strategies have been reported in the literature for the synthesis of amidine containing materials including the reduction of carbodiimides with sodium borohydride in iso-propanol, use of solvents like acetic acid under thermal conditions and use of promotors such as sulfated zirconia, hexafluoroisopropanol (HFIP) and γ-Fe 2 O 3 @SiO 2 -HBF 4 . [6,10] Another group of materials which their synthesis has drawn a strong interest from the synthetic organic chemists and biologists point of views, are benzimidazole, benzoxazole and benzothiazole and their derivatives. These five-membered heterocyclic rings are important classes of materials, that exhibit wide spectrum of activities from biological and pharmaceutical to industrial ones.…”

One-pot synthesis of novel pyrimido[4,5-b]quinolines and pyrido[2,3-d:6,5d′]dipyrimidines using encapsulated- γ-Fe2O3 nanoparticles

“…MNPs as solid acid catalyst have served as important functional materials in industrial processes. A few examples can be cited as, designing different Brønsted acids (ClSO 3 H, HClO 4 ,H B F 4 )o n γ -Fe 2 O 3 @SiO 2 [3][4][5][6] and functionalized hydroxyapatiteencapsulated-γ -Fe 2 O 3 magnetic nanoparticles. [7][8][9][10][11] Furthermore, the catalytic properties of Fe 2 O 3 NPs have been nicely exploited in various reactions, 12 such as oxidation of olefins and alcohols using O 2 or hydrogen peroxide, 13 direct borylation of arenes, 14 formation of 2-phenylquinazoline derivatives via condensation of benzylamine with 2-aminoaryl ketones 15 and C-H activation.…”