1125-21-9Relevant academic research and scientific papers
Selective aerobic oxidation of isophorone catalyzed by molybdovanadophosphate supported on carbon (NPMoV/C)
Hanyu, Atsushi,Sakurai, Yasunori,Fujibayashi, Shinya,Sakaguchi, Satoshi,Ishii, Yasutaka
, p. 5659 - 5662 (1997)
Isophorone was smoothly oxidized with molecular oxygen by molybdovanadophosphate supported on the active carbon ((NPMoV/C) to give 3-formyl-5,5-dimethyl-2-cyclohexen-1-one in relatively high selectivity. The regioselectivity of the oxidation by NPMoV/C was found to be just opposite to that of the conventional oxidations, The pore size of the supports appears to be an important factor governing the regioselectivity.
Chitosan-based Schiff base-metal complexes (Mn, Cu, Co) as heterogeneous, new catalysts for the β-isophorone oxidation
Thatte,Rathnam,Pise
, p. 727 - 737 (2014)
A new chitosan-based Schiff base was prepared and complexed with manganese, cobalt and copper. These Schiff base metal complexes were used as heterogeneous catalysts for the air oxidation of β-isophorone to ketoisophorone. The obtained complexes were characterized by means of FT-IR,1HNMR spectroscopy, elemental analysis, powder X-ray diffraction, field emission gun scanning electron microscopy, electron spin resonance spectroscopy, ICP-AES and solubility tests. Thermal properties were also investigated using thermal gravimetric analysis. Data obtained by thermal analysis revealed that these complexes showed good thermal stability. The conversion and selectivity of β-isophorone to ketoisophorone for each prepared catalyst was studied using a batch reactor and gas chromatography for product identification and quantification. The results were compared against the homogeneous bis-salicylaldehyde ethylenedi-imine-Mn catalyst. The use of methanol, acetone, methyl isobutyl ketone and n-hexane as solvent and its effect on conversion and selectivity was also investigated. Acetone was found to be a promising solvent for the β-isophorone oxidation. The role of triethyl amine and acetyl acetone in the oxidation reaction has also been investigated.
Selective synthesis of 4-hydroxyisophorone and 4-ketoisophorone by fungal peroxygenases
Aranda, Carmen,Municoy, Martí,Guallar, Víctor,Kiebist, Jan,Scheibner, Katrin,Ullrich, René,Del Río, José C.,Hofrichter, Martin,Martínez, Angel T.,Gutiérrez, Ana
, p. 1398 - 1405 (2019)
The recently discovered unspecific peroxygenases (UPOs) from the ascomycetes Chaetomium globosum and Humicola insolens were capable of selectively hydroxylating isophorone to 4-hydroxyisophorone (4HIP) and 4-ketoisophorone (4KIP), which are substrates of interest for the pharmaceutical and flavor-and-fragrance sectors. The model UPO from the basidiomycete Agrocybe aegerita was less regioselective, forming 7-hydroxyisophorone (and 7-formylisophorone) in addition to 4HIP. However, it was the most stereoselective UPO yielding the S-enantiomer of 4HIP with 88% ee. Moreover, using H. insolens UPO full kinetic resolution of racemic HIP was obtained within only 15 min, with >75% recovery of the R-enantiomer. Surprisingly, the UPOs from two other basidiomycetes, Marasmius rotula and Coprinopsis cinerea, failed to transform isophorone. The different UPO selectivities were rationalized by computational simulations, in which isophorone and 4HIP were diffused into the enzymes using the adaptive PELE software, and the distances from heme-bound oxygen in H2O2-activated enzyme to different substrate atoms, and the corresponding binding energies were analyzed. Interestingly, for process upscaling, full conversion of 10 mM isophorone was achieved with H. insolens UPO within nine hours, with total turnover numbers up to 5500. These biocatalysts, which only require H2O2 for activation, may represent a novel, simple and environmentally-friendly route for the production of isophorone derivatives.
Stereoselective hydroxylation of isophorone by variants of the cytochromes P450 CYP102A1 and CYP101A1
Dezvarei, Shaghayegh,Lee, Joel H.Z.,Bell, Stephen G.
, p. 29 - 37 (2018)
The stereoselective oxidation of hydrocarbons is an area of research where enzyme biocatalysis can make a substantial impact. The cyclic ketone isophorone was stereoselectively hydroxylated (≥95%) by wild-type CYP102A1 to form (R)-4-hydroxyisophorone, an important chiral synthon and flavour and fragrance compound. CYP102A1 variants were also selective for 4-hydroxyisophorone formation and the product formation rate increased over the wild-type enzyme by up to 285-fold, with the best mutants being R47L/Y51F/I401P and A74G/F87V/L188Q. The latter variant, which contained mutations in the distal substrate binding pocket, was marginally less selective. Combining perfluorodecanoic acid decoy molecules with the rate accelerating variant R47L/Y51F/I401P engendered further improvement with the purified enzymes. However when the decoy molecules were used with A74G/F87V/L188Q the amount of product generated by the enzyme was reduced. Addition of decoy molecules to whole-cell turnovers did not improve the productivity of these CYP102A1 systems. WT CYP101A1 formed significant levels of 7-hydroxyisophorone as a minor product alongside 4-hydroxyisophorone. However the F87W/Y96F/L244A/V247L CYP101A1 mutant was ≥98% selective for (R)-4-hydroxyisophorone. A comparison of the two enzyme systems using whole-cell oxidation reactions showed that the best CYP101A1 variant was able to generate more product. We also characterised that the further oxidation metabolite 4-ketoisophorone was produced and then subsequently reduced to levodione by an endogenous Escherichia coli ene reductase.
Enhanced catalytic activity and selectivity in oxidation of α-isophorone to ketoisophorone with phosphomolybdic acid
Murphy,Schneider,Mallat,Baiker
, p. 547 - 549 (2001)
Aerobic allylic oxidation of α-isophorone with phosphomolybdic acid as catalyst in combination with DMSO and potassium tert-butoxide provides ketoisophorone in unprecedented high yield. This study suggests that the solvent can play a pivotal role in directing selectivity in allylic oxidations of highly substituted cyclic olefins.
THE OXIDATION OF 2-CYCLOHEXEN-1-ONES TO 2-CYCLOHEXENE-1,4-DIONES
Freer, Vernon, J.,Yates, Peter
, p. 2031 - 2032 (1984)
Treatment of 5,5-dimethyl-2-cyclohexen-1-one and isophorone with phosphomolybdic acid, potassium dichromate, cupric sulfate, and air gives 5,5-dimethyl- and 3,5,5-trimethyl-2-cyclohexene-1,4-dione, respectively.In the latter reaction treatment of the crude product with aqueous base leads to the formation of 2,3,6,6-tetramethylanthracene-1,4,5,8-tetrone.
Kinetics Study on Oxidation of β-Isophorone Using Molecular Oxygen
Chen, Zhirong,Fang, Tingting,Yuan, Shenfeng,Yin, Hong
, p. 295 - 303 (2016)
The oxidation kinetics of β-isophorone (β-IP) using molecular oxygen catalyzed by iron(III) acetylacetonate was investigated in a lab-scale agitator bubbling reactor. β-IP was found to give keto-isophorone (KIP) and 4-hydroxy-3,5,5-trimethyl-2-cyclohexen-1-one (HIP) along with little isomerization product α-isophorone (α-IP). The results show that the oxidation reaction took place in the pseudo-first-order fast reaction regime. The experiment was conducted under the mass transfer reaction regime as the mass transfer resistances could not be easily eliminated. The intrinsic kinetics was obtained through apparent kinetics. The activation energy of oxidation of β-IP to KIP is 70.5 ± 4.1 kJ mol-1, and the value of ln AKIP is 33.53 ± 1.22. Meanwhile, the activation energy of oxidation of β-IP to HIP is 86.4 ± 5.4 kJ mol-1 and the value of ln AHIP is 36.23 ± 1.52, which could provide theoretical basis for industrial design, amplification of reactor, and the optimization of reaction.
Unexpected oxidation of β-isophorone with molecular oxygen promoted by TEMPO
Jia, Lu,Chen, Kexian,Wang, Congmin,Yao, Jia,Chen, Zhirong,Li, Haoran
, p. 15590 - 15596 (2014)
A novel and efficient protocol for the oxidation of β-isophorone (β-IP) using molecular oxygen without any additives catalyzed by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) has been established. The generally accepted catalytic mechanism of alcohols by the oxoammonium cation (TEMPO+) derived from TEMPO indeed fails to explain our experimental observations, because a favorable radical-based process is confirmed by electron spin resonance measurements. Our results show that a plateau of the time-dependence curve is observed in the oxidation of β-IP with TEMPO at low temperature, which is quite different from that of N-hydroxyphthalimide (NHPI). The proposed mechanism of this catalytic process is also compared with that of NHPI. The theoretically characterized reaction pathways show that unlike the phthalimide N-oxyl radical, TEMPO promotes the oxidation via its interaction with the active intermediate hydroperoxide (ROOH) rather than its initial interaction with β-IP, and byproduct water also assists the α-H atom transfer from ROOH to TEMPO. In addition to the intensive oxidation of alcohols catalyzed by TEMPO, the present study widens its specific applications in the active C-H bonds of hydrocarbons, and also provides new insights into its promoted metal-free oxidation. This journal is the Partner Organisations 2014.
Combination of two catalytic sites in a novel nanocrystalline TiO 2-iron tetrasulfophthalocyanine material provides better catalytic properties
Beyrhouty, Mirvat,Sorokin, Alexander B.,Daniele, Stephane,Hubert-Pfalzgraf, Liliane G.
, p. 1245 - 1248 (2005)
Mesoporous titania nanocrystals containing iron tetrasulfophthalocyanine (FePcS) have been synthesised by a one-pot hydrolytic process from a modified Ti alkoxide; the novel hybrid catalyst was efficient in heterogeneous oxidation of 2,3,6-trimethylphenol and β-isophorone suggesting a cooperative effect between TiO2 and FePcS catalytic sites. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2005.
Oxidation-isomerization of an olefin to allylic alcohol using titania-silica and a base co-catalyst
Beck,Mallat,Baiker
, p. 79 - 87 (2000)
The allylic oxidation of olefins is essential in synthetic organic chemistry, affording valuable α,β-unsaturated alcohols and carbonyl compounds. Allylic oxidation maintains the olefinic functionality in the product, thereby allowing further useful transformations. The potential two-step, one-pot synthesis of α,β-unsaturated alcohols from olefins was illustrated on the example of 4-hydroxyisophorone using titania-silica aerogels and basic co-catalysts. Kinetic analysis of the complex reaction network revealed that titania-silica was efficient in the epoxidation of β-isophorone (3,5,5-trimethyl-3-cyclohexen-1-one) with tert-butylhydroperoxide at 353 K, whereas the acid/base-catalyzed in situ rearrangement to 4-hydroxy-isophorone (4-hydroxy-3,5,5-trimethyl-cyclohex-2-eonone) was slow. Addition of solid bases such as CaO, Na2CO3 and KF/CaF2 accelerated the rearrangement and achieved ≤ 77.5% selectivity at 83% conversion in 3 hr. Stronger bases K2CO3, BaO, Mg-Al-O-tBu, guanidine bases) inhibited the epoxidation reaction due to the deactivation of the isolated Ti sites and favored isomerization of β-isophorone to α-isophorone. Hydrophobization of titania-silica by covalently bound surface phenyl groups greatly suppressed oligomerization and isomerization of β-isophorone but did not improve selectivity to 4-hydroxyl-isophorone.
