6705-49-3Relevant articles and documents
Isocyano Enones: Addition-Cyclization Cascade to Oxazoles
Chao, Allen,Lujan-Montelongo, J. Armando,Fleming, Fraser F.
, p. 3062 - 3065 (2016)
Copper iodide catalyzes the conjugate addition of organometallic and heteroatom nucleophiles to isocyano enones to afford oxazoles. A range of enolates, metalated nitriles, amines, and thiols undergo catalyzed conjugate addition to cyclic and acyclic oxoalkene isocyanides. Mechanistic studies suggest that copper complexation facilitates the nucleophilic attack on the isocyano enone to generate an enolate that cyclizes onto the isocyanide leading to a variety of substituted acyclic or ring-fused oxazoles.
Trinuclear Dioxidomolybdenum(VI) Complexes of Tritopic Phloroglucinol-Based Ligands and Their Catalytic Applications for the Selective Epoxidation of Olefins
Maurya, Mannar R.,Tomar, Reshu,Rana, Lata,Avecilla, Fernando
, p. 2952 - 2964 (2018)
Four trinuclear dioxidomolybdenum(VI) complexes, [{MoVIO2(H2O)}3ptk(bhz)3] (1), [{MoVIO2(H2O)}3ptk(fah)3] (2), [{MoVIO2(H2O)}3ptk(inh)3] (3), and [{MoVIO2(H2O)}3ptk(nah)3] (4), based on the tritopic central 2,4,6-triacetylphloroglucinol (H3ptk) ligands H6ptk(bhz)3 (I), H6ptk(fah)3 (II), H6ptk(inh)3 (III) and H6ptk(nah)3 (IV) (Hbhz = benzoylhydrazide, Hfah = 2-furanoylhydrazide, Hinh = isonicotinoylhydrazide and Hnah = nicotinoylhydrazide), respectively, are presented. All of the synthesized ligands, as well as their complexes, have been characterized by elemental, thermal, and electrochemical analyses, spectroscopic techniques (FTIR, UV/Vis, 1H and 13C NMR), and single-crystal X-ray studies of [{MoVIO2(H2O)}{MoVIO2(MeOH)}2ptk(bhz)3]·2H2O·1.25MeOH (1a) and [{MoVIO2(EtOH)}3ptk(fah)3]·3EtOH (2a). Each pocket of the ligands coordinates in a dibasic tridentate fashion through two oxygen atoms and one nitrogen atom to each metal center. Due to the presence of tridentate binding pockets in the ligands, each metal center conserves its octahedral structure by coordinating with water molecules in the synthesized complexes or by other solvent(s) in the crystal structures. These complexes were evaluated for the epoxidation of terminal and internal alkenes in the presence of H2O2 using NaHCO3 as a promoter. Under the optimized reaction conditions, all alkenes were converted to the corresponding epoxides selectively in good yield and high turnover number.
The catalytic epoxidation of 2-cyclohexen-1-one over uncalcined layered double hydroxides using various solvents
Sipiczki,ádám,Anitics,Csendes,Peintler,Kukovecz,Kónya,Sipos,Pálinkó
, p. 231 - 236 (2015)
The epoxidation reaction of an α,β-unsaturated ketone (2-cyclohexen-1-one), that is, an electron deficient C=C bond was performed over as-prepared and calcined layered double hydroxides (LDHs) of both the hydrotalcite- and the hydrocalumite type. It was found that the as-prepared LDHs always performed better than the calcined derivatives. Among them, the CaFe-LDH was the most active. The optimum reaction temperature and the most suitable solvent were also found after performing several set of reactions.
Epoxidation of conjugated C=C-bonds and sulfur-oxidation of thioethers mediated by NADH:FMN-dependent oxidoreductases
Mueller, Nicole Jasmin,Stueckler, Clemens,Hall, Melanie,MacHeroux, Peter,Faber, Kurt
, p. 1115 - 1119 (2009)
Three FMN-dependent oxidoreductases, YcnD and YhdA from Bacillus subtilis and Lot6p from Saccharomyces cerevisiae, oxidised α,β-unsaturated carbonyl compounds and a thioether, respectively, to furnish the corresponding racemic epoxides or sulfoxide, respectively. The mechanism of this enzyme-mediated (rather than enzyme-catalysed) oxidation was shown to proceed via the NADH-dependent reduction of O2, forming H2O 2, which acted as oxidant in a spontaneous (non-enzymatic) fashion. The Royal Society of Chemistry 2009.
Effect of Support Nature on Ruthenium-Catalyzed Allylic Oxidation of Cycloalkenes
Baptista, Daniel L.,Dupont, Jairton,Qadir, Muhammad I.
, (2022/01/12)
Allylic oxidation of cycloalkenes is a promising route to generate α,β-unsaturated ketones but encounters difficulties in selectivity control. Here, it is demonstrated that ruthenium nanoparticles (1–2?nm sized) decorated on TiO2 nanomaterials with different morphologies (nanoparticles, nanotubes and nanofibers) are demonstrated highly efficiency and selectivity for the selective aerobic oxidation of cyclohexene and indane. The as-prepared Ru/TiO2 nanofibers (NFs) represents higher activity for the allylic oxidation of cyclohexene (conv. 95%) with 78% selectivity toward 2-cyclohexen-1-one at 75?°C under 4?bar O2. Whereas, Ru/TiO2 nanoparticles (NPs) and Ru/TiO2 nanotubes (NTs) show 92 and 84% conversion, respectively. Upon switching to Al2O3 support, catalytic activity with Ru/Al2O3 is decreased significantly to 27%. Very high activity for indane (conv. 70%) toward 2,3-dihydro-1H-inden-1-one (selectivity 85%) has also been observed by using Ru/TiO2 NFs. Ru/TiO2 nanomaterials possess higher catalytic efficiency as compared to Ru NPs and TiO2 nanomaterials individually, representing a positive synergetic effect. Moreover, these reported results suggest that the higher activities of Ru/TiO2 NPs and Ru/TiO2 NFs are related to the crystalline structure, pore volume and surface area of the supports. Graphical Abstract: [Figure not available: see fulltext.]
Asymmetric Epoxidation of Enones Promoted by Dinuclear Magnesium Catalyst
Jaszczewska-Adamczak, Joanna A.,Mlynarski, Jacek
supporting information, p. 4247 - 4255 (2021/07/17)
Asymmetric synthesis with cheaper and non-toxic alkaline earth metal catalysts is becoming an important and sustainable alternative to conventional catalytic methodologies mostly relying on precious metals. In spite of some sustainable methods for enantioselective epoxidation of enones, the development of a well-defined and efficient catalyst based on magnesium complexes for these reactions is still a challenging task. In this perspective, we present the application of chiral dinuclear magnesium complexes for asymmetric epoxidation of a broad range of electron-deficient enones. We demonstrate that the in situ generated magnesium-ProPhenol complex affords enantioenriched oxiranes in high yields and with excellent enantioselectivities (up to 99% ee). Our extensive study verifies the literature data in this area and provides a step forward to better understand the factors controlling the oxygenation process. Elaborated catalyst offers mild reaction conditions and a truly wide substrate scope. (Figure presented.).