Three-component synthesis of N-sulfonylformamidines in the presence of magnetic cellulose supported N-heterocyclic carbene-copper complex, as an efficient heterogeneous nanocatalyst

Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes

“…Multiple methods exist for the synthesis of amidines in general, including the Pinner reaction, substitution of phenoxyimidates, Beckman-type rearrangements, and dehydrogenative coupling reactions, , or by catalysis with palladium ,− or nickel, as well as some multicomponent reactions. − Chang developed strategies for the synthesis of sulfonated and phosphorylated amidines via traditional click chemistry with azides, followed by a thermal N 2 exclusion, resulting in a net coupling of a nitrene to an alkyne. ,− However, the general (kinetic) stability of most triazoles puts severe limitations on the applicability of other azides, and this method also proved to be unsuitable for the synthesis of N -benzoyl or N -acyl amidines. , Nicasio and Pérez showed that a copper-catalyzed reaction of acetylenes with N -aroyl or N -acyl azides produces triazoles or oxazoles instead of N -acyl amidines. , In fact, development of direct methods for the synthesis of N- acyl amidines remains an unsolved challenge. Current synthetic routes to N- acyl amidines usually rely on reactions of premade primary amides with amino acetals or acylation of amidines with stoichiometric coupling reagents. − A direct, atom-efficient synthetic strategy is thus desired.…”

A decennary update on applications of metal nanoparticles (MNPs) in the synthesis of nitrogen- and oxygen-containing heterocyclic scaffolds

“…Shahrisa et al reported the synthesis of N-sulfonylformamidines (149) using an N-heterocyclic complex-copper complex supported on magnetic cellulose (NHC-Cu@MCs) from the three-component reaction among arylsulfonyl azide (148), secondary alicyclic amines (108c) such as morpholine, Nmethylpiperazine, piperidine and pyrrolidine, and triethylamine (117f) in acetonitrile at rt in 85-94% yield (Scheme 63). 133 The NCs were synthesized via the treatment of ionic liquid-graed magnetic cellulose with copper iodide, potassium tertbutoxide in THF, and further well characterized via TGA, VSM, SEM, XRD, EDX, and FT-IR. The scope of the reaction was explored with aliphatic amines, but was found to be unsuccessful for aromatic amines.…”

Magnetic sulfonated polysaccharides as efficient catalysts for synthesis of isoxazole-5-one derivatives possessing a substituted pyrrole ring, as anti-cancer agents

“…[21][22][23][24] Various magnetic functionalized polysaccharides have been recently prepared by our group whose copper complexes showed high catalytic activities for the synthesis of diverse N-sulfonylamidine derivatives. [25][26][27][28] In this work we report the preparation and fully characterization of Fe 3 O 4 magnetized sulfonated polysaccharides such as chitosan, cellulose and starch and evaluation of their catalytic activities in three-component reactions between N-substituted-pyrrole-2-carboxaldehyde, hydroxylamine-hydrochloride, and b-ketoesters to afford pyrrole containing isoxazole-5-ones. Since the hybrid molecules containing a pyrrole ring with other heterocyclic moiety, have shown biological activities such as antibacterial, anti-tumor, and antifungal (Fig.…”