Catalyst For One-pot Multicomponent Synthesis Research Articles

Captopril supported on magnetic graphene nitride, a sustainable and green catalyst for one-pot multicomponent synthesis of 2-amino-4H-chromene and 1,2,3,6-tetrahydropyrimidine

Captopril (CAP) is a safe, cost-effective, and environmentally organic compound that can be used as an effective organo-catalyst. Functional groups of captopril make it capable to attach to solid support and acting as promoters in organic transformations. In this work, captopril was attached to the surface of magnetic graphene nitride by employing a linker agent. The synthesized composite efficiently catalyzed two multicomponent reactions including the synthesis of 1,2,3,6-tetrahydropyrimidine and 2-amino-4H-chromene derivatives. A large library of functional targeted products was synthesized in mild reaction conditions. More importantly, this catalyst was stable and magnetically recycled and reused for at least five runs without losing catalytic activity.

Reusable magnetic catalysed synthesis of fluorescent imidazole derivatives: Their use as chromogenic and fluorogenic probes for metal cation's detection

In this contribution, we report the design of magnetic functionalized nanocellulose by an in-Situ approach. The fabricated polymer matrix was utilized as an efficient heterogeneous catalyst for one-pot multi-component synthesis of fluorescent multi-substituted imidazoles under green optimized conditions. The eco-friendly protocol afforded, short reaction times, excellent yields and catalyst easy recycling through magnetic recovery. The geometric optimization, MEP and FMOs have also been carried out at B3LYP‐D3/6–311++G (d, p) level of Density Functional Theory simulations in ethanol to elucidate the substituent's effect on molecule's planarity, surface studies, their electronic structure as well as their intermolecular charge transfer. Furthermore, the synthesized multi-substituted Imidazole derivatives exhibited remarkable fluorescent properties explored in cation metal's chromogenic and fluorogenic detection.

Oligosaccharides as Green Catalyst for One-Pot Multicomponent Synthesis of Spirooxindole Derivatives in Water

A one pot synthetic methodology has been developed towards multicomponent synthesis of spiro[indoline-3,2'- quinazoline]-2,4'(3'H)-dione from isatoic anhydride, isatin and primary amines in aqueous medium via supramolecular catalysis. An untapped potential of β-Cyclodextrin to mediate multicomponent reactions in aqueous medium has been revealed. Developed protocol was further verified by extrapolating the synthetic protocol using different isatin derivatives and amine analogues. In other synthetic scheme, some compounds were synthesized by reaction of various substituted benzaldehydes, Isatoic anhydride and primary amines. Synthesized library of compounds were further characterized using various spectroscopic techniques. During all the synthetic process, the catalytic efficiency of cyclodextrin was exploited. Efficiency of all the three forms of cyclodextrins were tested to find the best reaction for synthesis of spiro compounds. The usefulness of β-cyclodextrin was proved by showing its reusability. The essential role of β-cyclodextrin in the synthetic methodology is further proved by doing the control experiments which showed that no product was formed in the absence of catalyst. The attachment of reactant molecule was also proved by doing 1H NMR of reaction mixture at different time interval in D2O. On the basis of observation, a plausible mechanistic pathway of reaction was proposed. Other two forms of cyclodextrins were also eliminated on the ground of their insuitability in the formation of desired product. Catalyst reusability was studied and it was shown that our catalytic system is useful without any significant loss in catalytic potential even after 5 cycles. Catalyst recovery procedure was established and was used without any significant loss of catalytic activity upto 5 times.

Aluminized Polyborate: A New and Eco-friendly Catalyst for One-pot Multicomponent Synthesis of 1,3-Diaryl-3-(arylamino)propan-1-ones via Mannich Reaction

Aluminized Polyborate: A New and Eco-friendly Catalyst for One-pot Multicomponent Synthesis of 1,3-Diaryl-3-(arylamino)propan-1-ones via Mannich Reaction

Alpha-Casein: an efficient, green, novel, and eco-friendly catalyst for one-pot multi-component synthesis of bis (pyrazol-5-ols), dihydro-pyrano[2,3-c]pyrazoles and spiropyranopyrazoles in an environmentally benign manner

For the first time, alpha-Casein was used as an efficient and eco-friendly catalyst for an effective and facile preparation of dihydropyranopyrazoles and spiropyranopyrazoles. The synthesis of bis (pyrazol-5-ols) derivatives was developed via one-pot, pseudo-five-component condensation, and the target dihydropyrano[2,3-c]pyrazoles and spiropyranopyrazoles were prepared by one-pot four-component reaction. This new method of employing alpha-Casein, which is a green, recyclable, non-toxic and commercially available catalyst, offers advantages such as mild condition, short reaction times, easy work-up, no need for column chromatography, and high yields of the products which make it more economic than other environmentally synthetic protocols.

Novel task-specific ionic liquid [Et2NH(CH2)2CO2H][AcO] as a robust catalyst for the efficient synthesis of some pyran-annulated scaffolds under solvent-free conditions

A novel task-specific ionic liquid, 2-carboxy-N,N-diethylethanaminium acetate denoted as [Et2NH(CH2)2CO2H][AcO], is prepared in an easy process and fully characterized by using suitable methods such as FT-IR, 1H-NMR, 13C-NMR, and TG, DTG and DTA analyses. After preparation, the promoting ability of this catalyst for one-pot multicomponent synthesis of 2-amino-4H-chromenes, dihydropyrano[3,2-c]chromenes and dihydropyrano[2,3-c]pyrazoles using in situ-developed arylidenemalononitriles through Knoevenagel reaction under solvent-free conditions is described. The sustainable procedure, short reaction times (6–36 min), effortless work-up, non-chromatographic purification, good-to-excellent product yields (79–96%), ease of recovery and reusability of the catalyst up to six reaction runs without a decrease of activity are the notable features of the present protocol.

One-Pot Synthesis of 1,4-Dihydropyridine Derivatives Catalyzed by Silica-Coated Magnetic NiFe2O4 Nanoparticles-Supported H14[NaP5W30O110

Silica-coated magnetic NiFe2O4 nanoparticles-supported H14[NaP5W30O110] (NiFe2O4@SiO2-H14[NaP5W30O110]) was successfully synthesized and shown to be a versatile and highly efficient heterogeneous catalyst for one-pot multicomponent synthesis of 1,4-dihydropyridine derivatives under solvent-free condition. The synthesized catalyst can be magnetically recovered and reused four times without significant loss in catalytic efficiency.

Sulfated polyborate: a new and eco-friendly catalyst for one-pot multi-component synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones via Biginelli reaction

A highly efficient and improved synthetic methodology for the preparation of 3,4-dihydropyrimidin-2(1H)-one derivatives in good to excellent yieldviaBiginelli reaction of β-ketoesters/β-diketone, urea/thiourea and various aldehydes using new, efficient and recyclable sulfated polyborate catalyst under the solvent-free condition is reported.

β-Cyclodextrin-propyl sulfonic acid: a new and eco-friendly catalyst for one-pot multi-component synthesis of 3,4-dihydropyrimidones via Biginelli reaction

β-Cyclodextrin-propyl sulfonic acid (β-CD-PSA) is reported as a new and eco-friendly catalyst for the synthesis of 3,4-dihydropyrimidinones from one-pot multi-component reaction of aromatic aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions. The present methodology offers several advantages, such as shorter reaction time, high yields, mild reaction conditions and a simple work-up procedure. Furthermore, β-CD-PSA is inexpensive, biodegradable, and can be reusable. It could be reused six-times without a significant loss of catalytic activity.

Application of Silica Gel-supported Polyphosphoric Acid (PPA/SiO<sub>2</sub>) as a Reusable Solid Acid Catalyst for One-Pot Multi-Component Synthesis of 3,4,5-substituted furan-2(5H)-ones

3,4,5-substituted furan-2(5H)-ones were One-Pot Multi-Component synthesized by the reaction of aldehydes, amines and dialkyl acetylenedicarboxylates using silica gel-supported polyphosphoric acid (PPA/SiO2) at room temperature. This reaction provides a convenient and efficient synthetic method of furan-2(5H)-one derivatives, and also reusability of catalyst. Keywords: PPA/SiO2, 3, 4, 5-substituted furan-2(5H)-ones, aldehydes, amines, dialkyl acetylenedicarboxylates

Well-Ordered Mesoporous Silica Nanoparticles as a Recoverable Catalyst for One-Pot Multicomponent Synthesis of 4H-Chromene Derivatives

A simple, efficient, and environmentally benign protocol for the synthesis of 4 H -chromene derivatives was developed using bio-compatible, neutral, and recoverable mesoporous silica nanoparticles as a catalyst. The 4 H -chromene derivatives were obtained in excellent yields by three component reaction of an aldehyde or isatin, malononitrile, and cyclic 1,3-diketones in ethanol at 60 °C. Synthesis of 4 H- chromenes by three component condensation of aldehydes or isatines, malononitrile, and cyclic 1,3-diketones was performed using mesoporous silica nanoparticles as a reusable catalyst.

Iodine as an Efficient Catalyst for One-Pot Multicomponent Synthesis of β-Acetamido Ketones

Iodine efficiently catalyzes the three-component coupling of aromatic aldehydes, enolizable ketones or keto esters, and acetonitrile in the presence of acetyl chloride to afford β-acetamido ketones in good yields at room temperature.