Multicomponent Coupling Reaction Research Articles

Efficient Synthesis of α-Trifluoromethyl Carboxylic Acids and Esters through Fluorocarboxylation of gem-Difluoroalkenes.

A facile synthetic procedure for the preparation of α-trifluoromethyl carboxylic acids and esters was achieved through multicomponent coupling reactions between gem-difluoroalkenes, cesium fluoride, and carbon dioxide. The products were generated in moderate to excellent yields, and the synthetic utility of this method was demonstrated through the preparation of trifluoromethylated versions of popular nonsteroidal anti-inflammatory drugs (NSAIDs).

Efficient Synthesis of α‐Trifluoromethyl Carboxylic Acids and Esters through Fluorocarboxylation of gem‐Difluoroalkenes

AbstractA facile synthetic procedure for the preparation of α‐trifluoromethyl carboxylic acids and esters was achieved through multicomponent coupling reactions between gem‐difluoroalkenes, cesium fluoride, and carbon dioxide. The products were generated in moderate to excellent yields, and the synthetic utility of this method was demonstrated through the preparation of trifluoromethylated versions of popular nonsteroidal anti‐inflammatory drugs (NSAIDs).

Light Driven Water Oxidation Coupled With C‐N Coupling Reaction Using a Hybrid Cu‐PW12O40 Based Soft‐Oxometalate

AbstractInspired by photosynthesis, we have developed a system, which photochemically splits water to produce oxygen and protons and stores the released electron first in the metal oxide cluster followed by transfer to a Cu(II) centre to generate Cu(I) in situ in the reaction. Later the generated Cu(I) acts as an active catalyst for click reaction with a yield of up to 93% and for multi component coupling reaction to synthesize propargylamide with a yield of up to 87%.

Facile and efficient protocols for C–C and C–N bond formation reactions using a superparamagnetic palladium complex as reusable catalyst

Facile and efficient protocols for some multicomponent coupling reactions such as the Suzuki reaction and synthesis of polyhydroquinoline and 2,3-dihydroquinazoline-4-(1H)-one derivatives using a superparamagnetic palladium complex as catalyst have been developed.

A silica-supported titanium catalyst for heterogeneous hydroamination and multicomponent coupling reactions.

Highly dehydrated silica gel, SiO2700, gave a material with a total surface hydroxyl density of 0.31 ± 0.05 mmol g-1, 0.9 ± 0.1 Si-OH sites per nm2. Treatment of this material with Ti(NMe2)4 gave Ti(NMe2)3/SiO2700, which is 1.50% ± 0.07 Ti, where the titanium is bound to the surface, on average, through a single O-Si-Ti linkage. This material was tested for its properties as a catalyst for C-N bond forming reactions and was found to be a competent alkyne hydroamination and iminoamination catalyst. For iminoamination, which is the 3-component coupling of an alkyne, primary amine, and isonitrile, this heterogeneous catalyst was able to carry out some catalyses faster than previously reported homogeneous catalysts with lower catalyst loadings. The material is also a catalyst for the addition of aniline to dicyclohexylcarbodiimide to form a substituted guanidine. In addition, a known quinoline with biological activity was prepared using the heterogeneous catalyst in a one-pot procedure using half the catalyst loading of the previously reported synthesis.

Iridium-catalyzed 1,5-(aryl)aminomethylation of 1,3-enynes by alkenyl-to-allyl 1,4-iridium(i) migration.

A novel multicomponent coupling reaction involving the iridium-catalyzed 1,5-difunctionalization of 1,3-enynes with arylboronic acids and triazinanes is described. A key step in this 1,5-(aryl)aminomethylation reaction is the alkenyl-to-allyl 1,4-iridium(i) migration.

Serendipitous isolation of [Ag(PPh3)Cl]4 and its catalytic reactivity as a bimetallic partner to SnCl2

The reaction of [Ag(PPh3)3Cl] 1 with SnCl2 followed by recrystallization of the product led to the isolation of tetrameric chloro(triphenylphosphine)silver(I) [Ag4(PPh3)4Cl4] 2. The dual reagent combination of 2-SnCl2 show moderate catalytic activity in multicomponent coupling reactions involving CH activation.

Titanium-Catalyzed Hydroamination and Multicomponent Coupling with a Simple Silica-Supported Catalyst

Hydroamination and multicomponent coupling reactions catalyzed by homogeneous Ti(IV) complexes can produce valuable imines, amines, and other nitrogen-containing organic building blocks. Typically catalysts for this transformation are very sensitive to ancillary ligand design and often suffer from catalyst deactivation, necessitating use in a single reaction. Here, we have attempted to address these issues by moving toward a solid-supported Ti catalyst active for these reaction types. We present initial results to synthesize and probe the catalytic reactivity of silica-supported titanium amide precatalysts. With minimal treatment of commercially available fumed silica, Ti(NMe2)2/SiO2200 can be isolated upon addition of Ti(NMe2)4. This species gives high yields and high regioselectivity for hydroamination of a variety of alkynes with anilines. The solid-supported species is also an active catalyst for the formation of tautomers of unsymmetrical 1,3-diimines via three-component coupling of bulky anilines, a...

CuI@Sulfur-functionalized halloysite nanoclay: a novel recyclable catalyst for the ultrasonic-assisted synthesis of propargylamines: a combination of experimental and DFT simulation

A novel heterogeneous catalyst, CuI supported on sulfur functionalized halloysite (CuI@HNTs-S), was designed and synthesized through functionalization of the halloysite nanoclay surface with 3-mercaptopropyl trimethoxysilane and subsequent immobilization of CuI. The catalyst was characterized by using various characterization techniques such as FTIR, SEM/EDS, XRD, ICP and TGA. The catalytic activity of CuI@HNTs-S for the synthesis of propargylamines through ultrasonic-assisted multi-component A3 coupling reaction of aldehydes, phenyl acetylene and amines was also studied. The results established that CuI@HNTs-S could efficiently catalyze the reaction to furnish the desired products in excellent yield and in short reaction time. Notably the catalyst was recyclable and could be recycled with slight loss of the catalytic activity for five reaction runs. Then, the ability of pristine HNTs and sulfur functionalized HNTs toward CuI grabbing was compared quantitatively using molecular simulation. Calculated energies confirmed better performance of HNTs-S toward CuI physisorption, which decreases its leaching during catalytic reaction. This result was experimentally confirmed by observing the superior recyclability and low copper leaching of CuI@HNTs-S compared to CuI@HNTs.

Diastereoselective synthesis of propargylamines catalyzed by Cu-MCM-41

In this work, a rapid, efficient and protecting group free diastereoselective synthesis of propargylamines through a multicomponent coupling reaction between (S)-prolinol, phenylacetylene and commercially available aldehydes catalyzed by Cu-MCM-41 in heterogeneous phase is reported. The reactions were carried out under solvent free conditions with good yields and moderate reaction times. In all the cases, catalyst was recovered and reused up to five cycles. Recyclability of the catalyst, low catalyst loading, solvent and protecting group free conditions, and the use of inexpensive catalyst are the key features that provide green aspects to this synthetic protocol.

Aluminium and titanium modified mesoporous TUD-1: A bimetal acid catalyst for Biginelli reaction

Using a simple, non-surfactant template triethanolamine (TEA), bimetal (Al3+ and Ti4+ ions) incorporated mesoporous catalyst AlTiTUD-1 (Si/Al+Ti = 50) was synthesized. The catalyst was characterized by XRD (Low and High angle), N2 Sorption, FTIR, SEM, TEM, DR UV Visible, and pyridine adsorbed FT-IR techniques. The XRD and N2 sorption studies confirmed its amorphous, mesoporous nature, which possessed a BET surface area of 590 m2 g−1 and pore diameter of 4.4 nm. The Al3+ and Ti4+ co-ordination within the TUD-1 was evaluated by DR UV–Vis. Pyridine adsorbed FTIR revealed both Bronsted (B) and Lewis (L) acidity, which is responsible for the catalytic activity. The acid catalyst showed a good catalytic performance in Biginelli type multicomponent coupling reaction for the substituted aldehydes, ethyl acetoacetate and thiourea to yield about 70% in reflux condition.

Catalytic Versatility of Novel Sulfonamide Functionalized Magnetic Composites

The present work describes two novel magnetic composite catalysts, synthesized by functionalizing the silica/iron oxide composite surface with sulfaguanidine and sulfadiazine. The sulfaguanidine functionalized catalyst was found to be very efficient for multicomponent coupling reactions of phenylacetylene with various aldehydes and amines. The sulfadiazine functionalized catalyst was successfully applied in the synthesis of various 1,8-dioxo-octahydroxanthenes in water. Both the sulfaguanidine and sulfadiazine functionalized catalysts were very active and selective in the alkylation of toluene with benzyl chloride.

Ni-Catalyzed Formal Carbonyl-Ene Reaction of Terminal Alkenes via Carbon Dioxide Insertion

Nickel catalyzes the multicomponent coupling reaction of terminal alkenes, carbon dioxide, and organoaluminum reagents, leading to the synthesis of homoallylic alcohols in moderate-to-good yields with excellent regio- and stereoselectivities.

Highly Atom Economical Molecular Transformation via Hetero-Nickelacycle

Abstract Nickel is one of the most popular first row transition metals for coupling reactions. For the past two decades, catalytic multi-component coupling reactions via nickelacycles have been developed. Although the formation of nickelacycles has been believed an important key step in the catalytic reactions, the generation of nickelacycles by oxidative cyclization has been less studied. Thus, we have been focusing on the formation of nickelacycles from nickel(0) species and development of catalytic reactions without using coupling reagents to construct highly atom economical nickel-catalyzed multi-component connecting reactions.

Multicomponent Coupling Reaction for the Synthesis of Fused Furans

Key words multicomponent reaction - benzyl halides - isocyanides - Kornblum oxidation - furans

Copper–birhodanine complex immobilized on Fe3O4 nanoparticles: DFT studies and heterogeneous catalytic applications in the synthesis of propargylamines in aqueous medium

Heterogeneous magnetic nanocatalyst, Fe3O4@SiO2–Ligand–Cu (II) MNPs, reveals high catalytic performance within the synthesis of propargylamines using the multicomponent coupling reaction of aldehydes, phenylacetylene and secondary amines in water as a solvent. The substantial feature of this organic–inorganic hybrid magnetic nanocatalyst is the capability of straightforward separation of the reaction mixture by an external magnet which was retrieved ten times without significant loss of catalytic activity. This methodology has other advantages such as subordination to the principles of green chemistry and avoiding the use of expensive and harmful organic solvents. To study the stability and actual structure of birhodanine derivative–copper (II) complex, DFT calculations were also performed.

Cu nanoparticles decorated Cu organic framework based efficient and reusable heterogeneous catalyst for coupling reactions

Cu based metal organic frameworks were prepared and investigated as heterogeneous catalysts in the multi-component coupling reaction involving phenylacetylene as one of the building block for the synthesis of indolizine. Using the same set of reactants, chalcone was synthesized in neat condition. To enhance the catalytic activity and selectivity, Cu nanoparticles decorated Cu based metal organic framework was prepared using NaBH4 as reducing agent and sodium dodecyl sulfate as capping agent. Materials were characterized by the complementary combination of X-ray diffraction, N2-adsorption, scanning/transmission electron microscopic technique, Fourier transform infrared spectroscopy, UV–vis spectroscopy, X-ray photoelectron spectroscopy, and electrochemical method. For comparative purpose, Cu cluster compound and CuO were also prepared. Recycling and leaching experiments were performed to demonstrate the sustainability and robustness of the catalytic system. A wide range of indolizine and chalcones were prepared in high yields using this catalyst.

Novel Synthetic Approach for the Access of Functionalised 4H-Chromenes

A simple, efficient and high-yielding one-pot protocol for the synthesis of novel functionalised 4H-chromenes and chromene carboxylic acids has been developed using multi-component domino coupling reactions of anil-like compounds with 1,3-diketones and indole in the presence of formic acid catalyst under solvent-free conditions. The protocol avoids the use of expensive catalysts, toxic solvents and chromatographic separation.

Synthesis of mesoporous Ca-MCM catalysts and their use in suitable multicomponent synthesis of polyfunctionalized pyrans

Mesoporous Ca-MCM catalysts were prepared using a mixture of CaCO3, TEOS, cetyl trimethyl ammonium bromide (CTAB), triethanolamine (TEA), ethanol and H2O. Three catalysts with different CaCO3 contents, M-Ca 1 %, M-Ca 5 % and M-Ca 10 %, respectively, were prepared and characterized by N2 physisorption, XRD, FT-IR, XPS, TPD-CO2 and Pyridine-FTIR. A green and simple protocol was developed for the synthesis of 6-amino-4H-pyran scaffolds through a multicomponent coupling reaction of an aldehyde, malononitrile, and 1,3-dicarbonyl compound in different reaction solvents. This procedure was performed at room temperature (20 °C), obtaining good and excellent yields of 4H-pyran derivatives. The mesoporous materials are insoluble in polar media, which allows easy removal of the reaction products without affecting their catalytic activity. The leaching test showed an excellent stability, and Ca-MCM catalysts can be used three times without appreciable loss of their catalytic activity.

Multicomponent Coupling Reaction of Perfluoroarenes with 1,3-Butadiene and Aryl Grignard Reagents Promoted by an Anionic Ni(II) Complex.

An anionic Ni complex was isolated and its structure determined by X-ray crystallography. With such an anionic complex as a key intermediate, a regio- and stereoselective multicomponent coupling reaction of perfluoroarenes, aryl Grignard reagents, and 1,3-butadiene in a 1:1:2 ratio was achieved, resulting in the formation of 1,6-octadiene derivatives containing two aryl groups, one from the perfluoroarene and the other from the aryl Grignard reagent, at the 3- and 8-positions, respectively.