17619-97-5Relevant articles and documents
Modification of MnFe2O4 surface by Mo (VI) pyridylimine complex as an efficient nanocatalyst for (ep)oxidation of alkenes and sulfides
Bouzari, Narges,Bezaatpour, Abolfazl,Babaei, Behnam,Amiri, Mandana,Boukherroub, Rabah,Szunerits, Sabine
, (2021/03/04)
In this current paper, we report a new type of heterogeneous molybdenum (+6) complex, prepared by covalent grafting of cis-dioxo?molybdenum (VI) pyridylimine complex on the surface of MnFe2O4 nanoparticles (NP) and characterized using various physicochemical techniques. The recyclable prepared nanocatalyst was tested for sulfoxidation of sulfides and epoxidation of alkenes under solvent-free condition. The catalyst exhibited high turnover frequency for the oxidization of cyclooctene and cyclohexene (10,850 h?1) and thioanisole and dimethyl sulfide (41,250 h?1). The synthesized catalyst was found highly efficient, retrievable and eco-friendly catalyst for the (ep)oxidation of alkenes and sulfides in excellent yields in a short time. Furthermore, the synthesized nanocatalyst can be reused for four runs without apparent loss of its catalytic activity in the oxidation reaction.
Immobilization of molybdenum-based complexes on dendrimer-functionalized graphene oxide and their catalytic activity for the epoxidation of alkenes
Cheng, Maosheng,Fan, Zhanfang,Lin, Bin,Liu, Yang,Liu, Yongqing
, (2021/08/09)
Two novel molybdenum-based heterogeneous catalysts immobilized on dendrimer-functionalized graphene oxide via electrostatic interactions (Mo-1) or covalent bonding (Mo-2) are reported. The catalysts show excellent catalysis in epoxidation of alkenes with high conversion, better selectivity and good recyclability. The characteristics were identified by SEM, TEM (EDS-mapping), FT-IR, XRD, and XPS. The cause of the difference between the two catalysts is supported by DFT calculations.
Lipase catalysed oxidations in a sugar-derived natural deep eutectic solvent
Vagnoni, Martina,Samorì, Chiara,Pirini, Daniele,Vasquez De Paz, Maria Katrina,Gidey, Dawit Gebremichael,Galletti, Paola
, (2021/05/06)
Chemoenzymatic oxidations involving the CAL-B/H2O2 system was developed in a sugar derived Natural Deep Eutectic Solvent (NaDES) composed by a mixture of glucose, fructose and sucrose. Good to excellent conversions of substrates like cyclooctene, limonene, oleic acid and stilbene to their corresponding epoxides, cyclohexanone to its corresponding lactone and 2-phenylacetophenone to its corresponding ester, demonstrate the viability of the sugar NaDES as a reaction medium for epoxidation and Baeyer-Villiger oxidation.
Bifunctional Metal-Organic Layers for Tandem Catalytic Transformations Using Molecular Oxygen and Carbon Dioxide
Jiang, Xiaomin,Lan, Guangxu,Lin, Wenbin,Ni, Kaiyuan,Quan, Yangjian,Shi, Wenjie,Song, Yang,Wang, Cheng
supporting information, p. 16718 - 16724 (2021/10/21)
Tandem catalytic reactions improve atom- and step-economy over traditional synthesis but are limited by the incompatibility of the required catalysts. Herein, we report the design of bifunctional metal-organic layers (MOLs), HfOTf-Fe and HfOTf-Mn, consisting of triflate (OTf)-capped Hf6 secondary building units (SBUs) as strong Lewis acidic centers and metalated TPY ligands as metal active sites for tandem catalytic transformations using O2 and CO2 as coreactants. HfOTf-Fe effectively transforms hydrocarbons into cyanohydrins via tandem oxidation with O2 and silylcyanation whereas HfOTf-Mn converts styrenes into styrene carbonates via tandem epoxidation and CO2 insertion. Density functional theory calculations revealed the involvement of a high-spin FeIV (S = 2) center in the challenging oxidation of the sp3 C-H bond. This work highlights the potential of MOLs as a tunable platform to incorporate multiple catalysts for tandem transformations.
Substituent effects in dioxovanadium(V) schiff-base complexes: Tuning the outcomes of oxidation reactions
McCaffrey, Vanessa P.,Conover, Olivia Q.,Bernard, Michael A.,Yarranton, Jonathan T.,Lessnau, Nicholas R.,Hempfling, Jordan P.
, (2021/06/21)
Dioxovanadium(V) salicylaldehyde semicarbazone complexes with substituents on the ligand that span the range of electron donating (methoxy) to electron withdrawing (nitro) have been synthesized and characterized by NMR, IR, CV and EPR. The reactivity of these complexes toward the oxidation of styrene (as compared to the proteo complex and vanadyl acetylacetonate) has been studied in the presence of two different oxidants (hydrogen peroxide and tert-butyl hydrogen peroxide, TBHP). The complexes have been shown to exhibit different selectivity towards epoxidation versus oxidative cleavage based on the substitution of the ligand and the oxidant chosen. Epoxidation is favored with the methoxy substituted complex in the presence of hydrogen peroxide, while oxidative cleavage is the preferred reaction pathway for the nitro substituted complex with hydrogen peroxide. Conversions for these reaction are comparable to similar catalysts but with improved selectivity.
Self-assembled ionic liquid based organosilica-titania: A novel and efficient catalyst for green epoxidation of alkenes
Yari, Omolbanin,Elhamifar, Dawood,Shaker, Masoumeh
, (2021/04/06)
A novel titanium-containing self-assembled ionic liquid based hybrid organic-inorganic organosilica (Ti-ILOS) was prepared, characterized and applied as highly effective catalyst for the green epoxidation of alkenes in the presence of hydrogen peroxide as
Asymmetric Epoxidation of Unfunctionalized Olefins Using Novel Chiral Dihydroisoquinolinium Salts as Organocatalysts
Ali, K. Ben
, p. 638 - 646 (2021/06/02)
Abstract: Two new non-racemic chiral dihydroisoquinolinium salts with N-substituents bulkier than a methyl group have been synthesized from (1S,2R)-norephedrine. These salts were used to catalyze asymmetric epoxidation of a series of prochiral olefins. One of the two new catalysts provided higher enantioselectivities (up to 66% ee) than the reference salt containing an N-methyl substituent.
Microwave-Assisted Palladium-Catalyzed Reductive Cyclization/Ring-Opening/Aromatization Cascade of Oxazolidines to Isoquinolines
Xu, Xianjun,Feng, Huangdi,Van Der Eycken, Erik V.
, p. 6578 - 6582 (2021/09/02)
An efficient palladium-catalyzed reaction of N-propargyl oxazolidines for the construction of 4-substituted isoquinolines under microwave irradiation is developed. This transformation proceeds through a sequential palladium-catalyzed reductive cyclization/ring-opening/aromatization cascade via C-O and C-N bond cleavages of the oxazolidine ring. The practical value of this method has also been explored by conducting a millimole-scale reaction, as well as by transforming the isoquinoline into a key intermediate for the synthesis of a lamellarin analogue.
Dendrimer crown-ether tethered multi-wall carbon nanotubes support methyltrioxorhenium in the selective oxidation of olefins to epoxides
Bizzarri, Bruno Mattia,Botta, Lorenzo,Crucianelli, Marcello,Fanelli, Angelica,Ferella, Francesco,Gontrani, Lorenzo,Sadun, Claudia,Saladino, Raffaele
, p. 17185 - 17194 (2020/05/18)
Benzo-15-crown-5 ether supported on multi-wall carbon nanotubes (MWCNTs) by tethered poly(amidoamine) (PAMAM) dendrimers efficiently coordinated methyltrioxorhenium in the selective oxidation of olefins to epoxides. Environmentally friendly hydrogen peroxide was used as a primary oxidant. Up to first and second generation dendrimer aggregates were prepared by applying a divergent PAMAM methodology. FT-IR, XRD and ICP-MS analyses confirmed the effective coordination of methyltrioxorhenium by the benzo-15-crown-5 ether moiety after immobilization on MWCNTs. The novel catalysts converted olefins to the corresponding epoxides in high yield without the use of Lewis base additives, or anhydrous hydrogen peroxide, the catalyst being stable for more than six oxidative runs. In the absence of the PAMAM structure, the synthesis of diols largely prevailed.
Formal [3+2] cycloaddition reactions of electron-rich aryl epoxides with alkenes under Lewis acid catalysis affording tetrasubstituted tetrahydrofurans
Macías-Villamizar, Víctor E.,Cuca-Suárez, Luís,Rodríguez, Santiago,González, Florenci V.
supporting information, (2020/02/18)
We report on the regio- and stereoselective synthesis of tetrahydrofurans by reaction between epoxides and alkenes in the presence of a Lewis acid. This is an unprecedented formal [3+2] cycloaddition reaction between an epoxide and an alkene. The chemical reaction represents a very concise synthesis of tetrahydrofurans from accessible starting compounds.