Lewis Acid Surfactant-combined Catalyst Research Articles

Characterization and Comparison of Various Lewis Acid Surfactant Combined Catalyst (LASC) and Their Potential for Polylactic Acid Synthesis by Polycondensation

In Polylactic acid (PLA) production, there is a byproduct in the form of water, while Lewis acid catalysts such as Al(III), Ti(IV), and Sn(IV) which is commonly used for PLA production will be rapidly decomposed and deactivated by water. The aim for this research was to synthesize a Lewis acid water-tolerant catalyst called LASC (Lewis Acid Surfactant Combined Catalyst) by combining some Lewis metals with surfactant in the form of Sodium dodecyl sulfate (SDS) which will bind each other to become Fe(dodecyl sulfate)3 [Fe(DS)3], Al(dodecyl sulfate)3 [Al(DS)3], and Cu(dodecyl sulfate)2 [Cu(DS)2] and see their performance to the PLA production using polycondensation method. The catalyst was characterized by X-ray powder diffraction (XRD), thermal analysis (thermogravimetry analysis (TGA)), and spectroscopic analysis (FTIR). While the yield to the PLA production was analyzed gravimetrically. In the LASC spectrum, there are shifts and separations in symmetric and asymmetric modes compared to SDS spectrum which can be related to the interaction of dodecyl sulfate anions with Lewis metals cations (Fe(III), Al(III), and Cu(II). The XRD analysis shows identical position of 2θ at ± 2.4° for SDS and LASC. The interplanar spacing (dhkl) by XRD at 2θ = ± 2.4° were 3.74 nm, 3.63 nm, and 3.7 nm for SDS, Al(DS)3, and Cu(DS)2, respectively. Except for Fe(DS)3, the interplanar spacing at d001 is so small and only can be seen on the graph at 2θ = 2.32°. This LASC also show a good performance with a yield of 52%wt with ±1.2 mL of water was evaporated in the dehydration process of PLA production. The activity of this catalyst can contribute to enhancing the knowledge and applications of Lewis acid-surfactant-combined catalysts for PLA production.

Ultrasound and water-mediated synthesis of bis-thiazoles catalyzed by Fe(SD)3 as Lewis acid-surfactant-combined catalyst

ABSTRACTPreparation of bis-aminothiazoles under different conditions including synthesis in EtOH under ultrasound irradiation and also in water in the presence of Fe(SD)3 as Lewis acid-surfactant-combined catalyst (LASC) under ultrasound irradiation has been studied. The results were compared with the traditional reflux method. Also, the results confirmed the efficiency of the synthesis in water and under ultrasound irradiation technique. Moreover, the antibacterial activity of products was investigated using the well-diffusion method against bacterial strains including Micrococcus luteus, Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis. All of the products showed good antibacterial activity against M. luteus and E. coli. Most of the products showed antibacterial activity higher than erythromycin against M. luteus, E. coli, and B. subtilis.

Efficient, stable, and reusable Lewis acid–surfactant-combined catalyst: One-pot Biginelli and solvent-free esterification reactions

Cerium(III) trislaurylsulfonate (Ce(LS)3), a Lewis acid and surfactant combined catalyst, was prepared and characterized by SEM, SEM-EDX, XRD, NMR, FT-IR, TG, and elemental analysis. Ce(LS)3 was found to be stable and efficient to catalyze one-pot Biginelli and solvent-free esterification reactions. Furthermore, Ce(LS)3 is easy to recycle after reaction by pouring into cold water and filtration. Present work will shed deep insight into the understanding of the catalytic nature of LASCs, and extend its application in important organic transformations.

ChemInform Abstract: Fe(DS)3, an Efficient Lewis Acid — Surfactant Combined Catalyst (LASC) for the One‐Pot Synthesis of Chromeno[4,3‐b]chromene Derivatives by Assembling the Basic Building Blocks.

AbstractThe use of ferric dodecylsulfate renders possible a three‐component heteroannulation for the synthesis of the title compounds in water.

Nano-TiO2 on Dodecyl-Sulfated Silica: As an Efficient Heterogeneous Lewis Acid–Surfactant-Combined Catalyst (HLASC) for Reaction in Aqueous Media

A reusable Lewis acid–surfactant-combined catalyst (LASC), using immobilization of nano-TiO2 on dodecyl-sulfated silica support (NTDSS), has been developed. To obtain this catalyst system, sodium dodecyl sulfate (SDS) was reacted with silica chloride (SC) to generate a dodecyl-sulfated silica (DSS) substrate. Subsequently, the addition of TiCl4 to a water solution of DSS resulted in the immobilization of nano-TiO2 on the surface of a DSS substrate. The NTDSS catalyst was characterized using different techniques such as TEM, SEM, XRD, ICP, and FT-IR. The catalyst was successfully used for the synthesis of coumarin derivatives via Pechmann condensation in water as a green solvent. High catalytic activity of the catalyst in water media can be a result of colloidal particle formation on the surface of the NTDSS catalyst due to the grafted DS moieties on the surface of silica, which act as a surfactant. It seems that the generation of emulsion droplets containing nano-TiO2 on the surface of the catalyst would function as an effective reaction reactor to accelerate the rate of the reaction in water media.

Fe(DS)3, an efficient Lewis acid-surfactant-combined catalyst (LASC) for the one pot synthesis of chromeno[4,3-b]chromene derivatives by assembling the basic building blocks

A highly efficient multicomponent heteroannulation protocol for the synthesis of a library of chromeno[4,3-b]chromene derivative has been developed by applying a Lewis acid-surfactant-combined catalyst (LASC) [Fe(DS)3]. The LASC converted the initially floating reaction mass into a homogeneous mixture, which on stirring became a turbid emulsion of colloidal aggregates. The shape and size of the colloidal aggregates are confirmed by optical microscopy and DLS. The aqueous reaction medium, dual role of the catalyst in aqueous media, easy recovery of the catalyst, and high yield make the protocol attractive, sustainable, and economical.

Lewis acid–surfactant-combined catalyzed synthesis of 4-aminocyclopentenones from glycals in water

4-Aminocyclopentenones were synthesized from readily available glycals and secondary anilines, with the aid of a Lewis acid–surfactant-combined catalyst. The reactions proceeded via a 4π conrotatory electrocyclization, affording the corresponding 4-aminocyclopentenones in good yields with excellent diastereoselectivities.

ChemInform Abstract: Catalytic Asymmetric Synthesis of Antimalarial Alkaloids Febrifugine and Isofebrifugine and Their Biological Activity.

Antimalarial alkaloids febrifugine (1) and isofebrifugine (2) were efficiently synthesized from simple achiral starting materials on the basis of the catalytic asymmetric synthesis. The first key reaction was performed using the tin(II)-mediated catalytic asymmetric aldol protocol to afford chiral aldehyde 3 in high yield with high diastereo- and enantioselectivities. The second key step, a Mannich-type reaction, did not give satisfactory results according to the conventional methods. We then developed a novel aqueous Mannich-type three-component reaction of an aldehyde, an amine, and a vinyl ether using a Lewis acid−surfactant combined catalyst (LASC), and the key intermediates 16 and 17 were obtained in high yields. The final coupling reactions of bromoacetone 14 with 4-hydroxyquinazoline were carried out using basic conditions, and successive deprotection gave 1 and 2, respectively, without any isomerization. These unambiguous total asymmetric syntheses revealed that the absolute configurations of febr...

A novel catalyst zinc(II) perfluorooctanoate [Zn(PFO) 2]-catalyzed three-component one-pot reaction: Synthesis of quinazolinone derivatives in aqueous micellar media

A new type of Lewis acid-surfactant-combined catalyst (LASC), zinc(II) perfluorooctanoate [Zn(PFO) 2], was prepared and applied as a favorable surfactivity catalyst in three-component one-pot cyclocondensation reaction of isatoic anhydride with amines and aldehydes to afford the corresponding quinazolinone derivatives in good yields. Reactions occurred under aqueous micellar media in high atom economy. It was found that this catalyst could be easily quantitatively recovered after the reaction completed and could be reused for at least three cycles without any loss of activity. Furthermore, a mechanism to rationalize the reaction was proposed.

ChemInform Abstract: Three‐Component Reaction of 2‐Alkynylbenzaldehyde, Amine, and Nucleophile Using Lewis Acid Surfactant Combined Catalyst in Water.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Three-component reaction of 2-alkynylbenzaldehyde, amine, and nucleophile using Lewis acid-surfactant combined catalyst in water

Lewis acid-surfactant combined catalyst (LASC) catalyzed three-component reactions of 2-alkynylbenzaldehyde, amines, and nucleophiles (alkyne, nitromethane, or diethyl phosphate) in water under ultrasonic conditions afforded the corresponding 1,2-dihydroisoquinoline derivatives in good yields.

Aluminum tris (dodecyl sulfate) trihydrate Al(DS) 3·3H 2O as an efficient Lewis acid–surfactant-combined catalyst for organic reactions in water : Efficient conversion of epoxides to thiiranes and to amino alcohols at room temperature

High yielding preparation of structurally different thiiranes, β-amino alcohols and bis(β-amino) alcohols from the reaction of epoxides with thiourea and amines in the presence of catalytic amounts of aluminum tris (dodecyl sulfate) trihydrate Al(DS) 3·3H 2O as a Lewis acid–surfactant-combined catalyst at room temperature in water has been described. Ring opening of epoxides with amines in the presence of this catalyst proceeded with high chemo- and regioselectivity.

Use of a Lewis Acid Surfactant Combined Catalyst in Cationic Polymerization in Miniemulsion: Apparent and Hidden Initiators

A Lewis acid surfactant combined catalyst (LASC) was tentatively used in a cationic polymerization in miniemulsion of p-methoxystyrene (pMOS). In a first part, the initiating potential of trisdodecyl sulfate ytterbium (Yb(DS)3, 0.25H2O) was evidenced in the solution polymerization of pMOS initiated by the corresponding chlorinated adduct pMOS−HCl. Miniemulsion polymerizations of pMOS performed using the same initiating system gave rise to oligomers, but experimental conditions chosen could not evidence the expected LASC-mediated cationic polymerization process. Further studies showed that LASC is located at the interface and acts only as a surfactant together with SDS. The polymerization occurred due to the hydrolysis of pMOS−HCl. The resulting acidification of the water phase leads to the transformation of SDS into its sulfuric acid form acting as an inisurf according to an interfacial cationic polymerization process. Latex particles of pMOS incorporating narrowly distributed low molar mass chains were o...

Organic Synthesis Inside Particles in Water: Lewis Acid−Surfactant-Combined Catalysts for Organic Reactions in Water Using Colloidal Dispersions as Reaction Media

A Lewis acid−surfactant-combined catalyst (LASC) has been developed and applied to Lewis acid-catalyzed organic reactions in water. LASCs are composed of water-stable Lewis acidic cations such as scandium and anionic surfactants such as dodecyl sulfate and dodecanesulfonate and are easily prepared. These catalysts have been successfully used for various typical carbon−carbon bond-forming reactions such as aldol, allylation, and Mannich-type reactions in water. Furthermore, the results of aldol reactions in various solvents show that water is the best solvent for the LASC-catalyzed reactions. A preliminary kinetic study of the aldol reaction showed that the initial rate in water was 1.3 × 102 times higher than that in dichloromethane. In the workup procedure, it was demonstrated that centrifugation of the reaction mixture led to phase separation without addition of any organic solvents. The LASCs was found to form stable colloidal dispersions rapidly in the presence of reaction substrates in water, even wh...

Facile synthesis of α-amino phosphonates in water using a Lewis acid–surfactant-combined catalyst

Three-component reactions of aldehydes, amines and triethyl phosphite were efficiently catalyzed by scandium tris(dodecyl sulfate) at ambient temperature in water to give various α-amino phosphonates in high yields.

Synthetic reactions using organometallics in water. Aldol and allylation reactions catalyzed by Lewis acid–surfactant-combined catalysts/Brønsted acids systems

Aldol reactions of aldehydes with silyl enolates and allylation reactions with tetraallyltin have been successfully carried out using Lewis acid–surfactant-combined catalysts/Brønsted acids systems. Remarkable enhancement of reactivity by a Brønsted acid such as HCl was observed in these reactions in the presence of a Lewis acid–surfactant-combined catalyst such as scandium tris(dodecyl sulfate) or scandium trisdodecanesulfonate in water. The addition of Brønsted acids was also effective for catalytic asymmetric aldol reactions in water using copper bis(dodecyl sulfate) and a chiral bis(oxazoline) ligand.

Catalytic Asymmetric Synthesis of Antimalarial Alkaloids Febrifugine and Isofebrifugine and Their Biological Activity.

Antimalarial alkaloids febrifugine (1) and isofebrifugine (2) were efficiently synthesized from simple achiral starting materials on the basis of the catalytic asymmetric synthesis. The first key reaction was performed using the tin(II)-mediated catalytic asymmetric aldol protocol to afford chiral aldehyde 3 in high yield with high diastereo- and enantioselectivities. The second key step, a Mannich-type reaction, did not give satisfactory results according to the conventional methods. We then developed a novel aqueous Mannich-type three-component reaction of an aldehyde, an amine, and a vinyl ether using a Lewis acid-surfactant combined catalyst (LASC), and the key intermediates 16 and 17 were obtained in high yields. The final coupling reactions of bromoacetone 14 with 4-hydroxyquinazoline were carried out using basic conditions, and successive deprotection gave 1 and 2, respectively, without any isomerization. These unambiguous total asymmetric syntheses revealed that the absolute configurations of febrifugine and isofebrifugine were not (2'S,3'R) and (2'R,3'R) as reported previously but (2'R,3'S) and (2'S,3'S), respectively (1' and 2'). Finally, antimalarial activities of the synthesized febrifugine and isofebrifugine, and their antipodes, were examined. It was revealed that the activities and selectivities of natural febrifugine and isofebrifugine were much higher than those of the antipodes.