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Mixed crystals containing the dioxo complex [{Ph3SiO} 2VO2]- and novel pentacoordinated oxoperoxo complex [{Ph3SiO}2- VO(O2)]-: X-ray crystal structure and assessment as oxidation catalysts
[n-Bu4N][{Ph3SiO}2VO2] reacts with H2O2 tomixed-crystal yield an oxoperoxo complex which crystallizes as a mixed-crystal compound, [P(C6H5) 4][{(C6H5)3 SiO}2VO 2]x[{(C6H5)3 SiO} 2VO(O2)]1-x, 1 (x = 0.57). It has been characterized by elemental analysis and spectroscopy (51V NMR, UV-visible and IR). The X-ray structure analysis reveals the presence of two interrelated anions: [{Ph3SiO}2VvO 2]-, 1a, and [{Ph3SiO}2V vO(O2)]-, 1b with a cisoid geometry of the (VO(O2)}+ moiety. The two structures differ only slightly: anion 1a exhibits unusual tetrahedral coordination around the vanadium centre found in the precursor, whereas the geometry at the metal ion in 1b can be described as a trapezoidal pyramid. Steric constraints due to Ph 3SiO- ligands and PPh4+ cations are responsible for this geometry. The reactivity of 1 in the C-C bond cleavage of 2-methylcyclohexanone under anaerobic conditions has been studied. The results suggest that peroxygen species are involved in the oxidative cleavage of C-C bonds of cycloalkanones.
Vennat, Maxence,Bregeault, Jean-Marie,Herson, Patrick
p. 908 - 913
(2004)
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Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl
A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C-C bond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
He, Tianyu,Chen, Dengfeng,Qian, Shencheng,Zheng, Yu,Huang, Shenlin
p. 6525 - 6529
(2021/09/02)

Visible Light-Driven, Copper-Catalyzed Aerobic Oxidative Cleavage of Cycloalkanones
A visible light-driven, copper-catalyzed aerobic oxidative cleavage of cycloalkanones has been presented. A variety of cycloalkanones with varying ring sizes and various α-substituents reacted well to give the distal keto acids or dicarboxylic acids with moderate to good yields.
Xin, Hong,Duan, Xin-Hua,Yang, Mingyu,Zhang, Yiwen,Guo, Li-Na
p. 8263 - 8273
(2021/06/30)

Azolium/Hydroquinone Organo-Radical Co-Catalysis: Aerobic C?C-Bond Cleavage in Ketones
Organo-radical catalysts have recently attracted great interest, and the development of this field can be expected to broaden the applications of organocatalysis. Herein, the first example of a radical-generating system is reported that does not require any photoirradiation, radical initiators, or preactivated substrates. The oxidative C?C-bond cleavage of 2-substituted cyclohexanones was achieved using an azolium salt and a hydroquinone as co-catalysts. A catalytic mechanism was proposed based on the results of diffusion-ordered spectroscopy and cyclic voltammetry measurements, as well as computational studies.
Nakatsuji, Yuya,Kobayashi, Yusuke,Masuda, Sakyo,Takemoto, Yoshiji
supporting information
p. 2633 - 2637
(2021/02/03)

Catalytic oxidation of α-substituted cyclohexanone with steric hindrance to 6-oxohexanoic acid involved during the total synthesis of (+)-biotin
A homogeneous catalyst system FeCl3/DMSO was developed to catalyze α-substituted cyclohexanone to corresponding 6-oxohexanoic acid, an important intermediate involved during the synthesis of (+)-biotin. A highly efficient oxidation with 95.3 % of conversion and 88.0 % of selectivity was achieved using oxygen as the oxidant, which shows great advantage over the traditional peroxide method from industrial aspects. The detailed reaction process was evaluated to determine the parallel reactions scheme consisted by two oxidative reactions and one chlorination reaction. The [Fe(DMSO)4Cl2]Cl complex detected by UV–vis and FT-IR spectrometer was proposed as the active component during the catalytic process. The control experiments, capture of important intermediates, and kinetic study were performed, which showed the oxidation proceeded via the combination of ionic and radical pathway. The FeCl3/DMSO can be recycled with minor yield loss.
Li, Haoran,Ma, Qiyi,Mao, Jianyong,Yao, Jia,Yuan, Haoran
(2021/08/13)

Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
supporting information
p. 14365 - 14373
(2019/09/06)

OXIDATIVE CLEAVAGE OF OLEFINS, EPOXIDES AND ALCOHOLS
Provided is a process for producing a compound I comprising at least one functional group chosen in the group consisting of epoxy group, hydroxyl group and carbonyl group and by reacting a compound J comprising at least one functional group chosen in the group consisting of alkenyl group, epoxy group and hydroxyl group with an an oxidant in the presence of solid amphiphilic catalytic particles A and solid amphiphilic catalytic particles B.
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(2019/02/06)

Colloidal tectonics for tandem synergistic Pickering interfacial catalysis: Oxidative cleavage of cyclohexene oxide into adipic acid
Supramolecular preorganization and interfacial recognition can provide useful architectures for colloidal building. To this aim, a novel approach, based on colloidal tectonics involving two surface-active particles containing both recognition and catalytic sites, has been developed for controlling the formation and the properties of Pickering emulsions. This was illustrated by the combination of dodecyltrimethylammonium phosphotungstate nanoparticles, [C12]3[PW12O40], and silica particles functionalized with alkyl and sulfonic acid groups, [Cn/SO3H]@SiO2. The interfacial self-assembly occurs by the penetration of the alkyl chains of [Cn/SO3H]@SiO2 into the [C12]3[PW12O40] supramolecular porous structure constituted of polar and apolar regions. The emulsions were used as a non-nitric acid route for adipic acid synthesis from the one-pot oxidative cleavage of cyclohexene oxide with aqueous H2O2. The catalytic performance was significantly boosted due to the synergistic interactions between the particles.
Yang, Bingyu,Leclercq, Lo?c,Schmitt, Véronique,Pera-Titus, Marc,Nardello-Rataj, Véronique
p. 501 - 507
(2019/01/10)

An efficient method for retro-Claisen-type C-C bond cleavage of diketones with tropylium catalyst
The retro-Claisen reaction is frequently used in organic synthesis to access ester derivatives from 1,3-dicarbonyl precursors. The C-C bond cleavage in this reaction is usually promoted by a number of transition-metal Lewis acid catalysts or organic Br?nsted acids/bases. Herein we report a new convenient and efficient method utilizing the tropylium ion as a mild and environmentally friendly organocatalyst to mediate retro-Claisen-type reactions. Using this method, a range of synthetically valuable substances can be accessed via solvolysis of 1,3-dicarbonyl compounds.
Hussein,Huynh,Hommelsheim,Koenigs,Nguyen
supporting information
p. 12970 - 12973
(2018/11/23)

"release and catch" catalysis by tungstate species for the oxidative cleavage of olefins
The oxidative cleavage of olefins produces valuable carbonyl compounds, and thus, the development of green catalytic methods using H2O2 as an oxidant is highly desired. In this work, we have successfully developed an efficient catalytic system for the oxidative cleavage of olefins and related compounds using H2O2. In the presence of tungstate species supported on zinc-modified tin dioxide (W/Zn-SnO2), the oxidative cleavage of 1-methyl-1-cyclohexene proceeds efficiently through multistep reaction pathways involving oxygenation, hydrolysis, perhydrolysis, and isomerization reactions. In this reaction system, active peroxotungstate species, generated by the reaction of the supported tungstate species with H2O2, are released into the solution during the course of the reaction. At the end of the reaction (after the complete consumption of H2O2), the released tungstate species are re-captured by the support. The W/Zn-SnO2 catalyst can be reused at least nine times for the oxidative cleavage of 1-methyl-1-cyclohexene without loss of catalytic performance and can be applied to the oxidation of various other substrate molecules.
Yoshimura, Yu,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
p. 1662 - 1670
(2017/07/22)

Additional nucleophile-free FeCl3-catalyzed green deprotection of 2,4-dimethoxyphenylmethyl-protected alcohols and carboxylic acids
The deprotection of the methoxyphenylmethyl (MPM) ether and ester derivatives can be generally achieved by the combinatorial use of a catalytic Lewis acid and stoichiometric nucleophile. The deprotections of 2,4-dimethoxyphenylmethyl (DMPM)-protected alcohols and carboxylic acids were found to be effectively catalyzed by iron(III) chloride without any additional nucleophile to form the deprotected mother alcohols and carboxylic acids in excellent yields. Since the present deprotection proceeds via the self-assembling mechanism of the 2,4-DMPM protective group itself to give the hardly-soluble resorcinarene derivative as a precipitate, the rigorous purification process by silica-gel column chromatography was unnecessary and the sufficiently-pure alcohols and carboxylic acids were easily obtained in satisfactory yields after simple filtration.
Sawama, Yoshinari,Masuda, Masahiro,Honda, Akie,Yokoyama, Hiroki,Park, Kwihwan,Yasukawa, Naoki,Monguchi, Yasunari,Sajiki, Hironao
p. 778 - 784
(2016/07/16)

Ruthenium(II)-Catalyzed Hydration of Terminal Alkynes in PEG-400
The ruthenium(II)-catalyzed hydration of terminal alkynes in PEG-400 to yield methyl ketones through Markovnikov addition of water across alkyne is reported.
Mainkar, Prathama S.,Chippala, Venkataraju,Chegondi, Rambabu,Chandrasekhar, Srivari
supporting information
p. 1969 - 1972
(2016/08/10)

One-pot room-temperature conversion of cyclohexane to adipic acid by ozone and UV light
Nitric acid oxidation of cyclohexane accounts for ～95% of the worldwide adipic acid production and is also responsible for ～5 to 8% of the annual worldwide anthropogenic emission of the ozone-depleting greenhouse gas nitrous oxide (N2O). Here we report a N2O-free process for adipic acid synthesis.Treatment of neat cyclohexane, cyclohexanol, or cyclohexanone with ozone at room temperature and 1 atmosphere of pressure affords adipic acid as a solid precipitate. Addition of acidic water or exposure to ultraviolet (UV) light irradiation (or a combination of both) dramatically enhances the oxidative conversion of cyclohexane to adipic acid.
Hwang, Kuo Chu,Sagadevan, Arunachalam
p. 1495 - 1498
(2015/02/19)

Natural phosphate modified by vanadium: A new catalyst for oxidation of cycloalkanones and α-ketols with oxygen molecular
In this work, we have studied the catalytic oxidative cleavage of C-C bonds of cycloalkanones and α-ketols, in the presence of natural phosphate (NP) type fluorapatite, Ca10(PO4)6F2, and dioxygen. The aim was to find a heterogeneous system clean and efficient alternative to the industrial oxidation of cyclohexanone to adipic acid with nitric acid. The modification of the NP by vanadium leads to the preparation of a new catalyst V/PN. The latter was characterized by: XRD, FTIR, SEM and BET. It appears that vanadium is well dispersed on the surface of the NP. Using 2-methylcyclohexanone as model substrate, we optimized the conditions of reaction in order to make the system 'V/PN/O2' more performance. The comparative study between the two catalytic systems 'PN/O2' and 'V/PN/O2' shows that the latter is more active. Finally, the system 'V/PN/O2' has been recycled but low leaching of vanadium was observed in the first use of the catalyst.
Dakkach, Mohamed,Atlamsani, Ahmed,Sebti, Sa?d
scheme or table
p. 482 - 492
(2012/07/31)

K-10 montmorillonite: An efficient and reusable catalyst for the aerobic CC bond cleavage of α-substituted ketones
A commercially available acid-activated montmorillonite clay catalyst, K10 montmorillonite, was tested for the catalytic oxidation of cyclic ketones in the presence of molecular oxygen under mild conditions (343 K and atmospheric pressure). K10 montmorillonite catalyzed the oxidative cleavage of CC bonds in 2-methylcyclohexanone, 2-phenylcyclohexanone, 2-hydroxylcyclohexanone and 1,2-cyclohexanedione with good activity and excellent selectivity toward the formation of the corresponding ketoacids and diacids. The effects of acidity, amount of catalyst, temperature and solvent on the catalytic activity were investigated. Furthermore, this catalyst was reusable without any appreciable loss in activity and selectivity.
El Younssi, Iman,Rhadfi, Tarik,Atlamsani, Ahmed,Draoui, Khalid,Quisefit, Jean-Paul,Herbst, Frederic
p. 437 - 445,9
(2020/07/31)

A one-pot method for the oxidation of unsaturated organic compounds
The present invention concerns a method for the oxidative cleavage of unsaturated carbon-carbon bonds into carboxylic acids or ketones using a manganese catalyst and hydrogen peroxide.
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(2012/02/05)

METHOD FOR THE OXIDATION OF UNSATURATED ORGANIC COMPOUNDS
The present invention concerns a method for the oxidative cleavage of unsaturated carbon-carbon bonds into carboxylic acids or ketones using a manganese catalyst and hydrogen peroxide.
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Page/Page column 21-22

(2012/02/05)

METHOD FOR PRODUCING OXYGEN-CONTAINING COMPOUND
[Problem] There is provided a method for producing an oxygen-containing compound safely and with improved reaction efficiency, in which an undesired peroxide is unlikely to be produced, and efficient heat exchange of the ozonization can be achieved. [Mean for solving the Problem] The method comprises an ozonization reaction step of continuously supplying, together with an organic compound, ozone having an oxygen content of less than 10% in a dissolved state in high-pressure carbon dioxide to an ozonization reaction section having a thin tubular shape, and reacting the ozone and the organic compound under conditions that suppress generation of oxygen due to thermal decomposition of the ozone, thereby continuously producing an ozonide; and a decomposition reaction step of continuously supplying the ozonide produced in the ozonization reaction step to a decomposition reaction section having a thin tubular shape, thereby continuously producing an oxygen-containing compound, the decomposition reaction step being provided in a manner continuous with the ozonization reaction step.
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Page/Page column 21-22

(2012/01/11)

Retro-claisen condensation with FeIII as catalyst under solvent-free conditions
An iron(III) salt catalyzed retro-Claisen condensation between an alcohol and a 1,3-diketone was investigated. The mechanism involves the formation of a metal-induced sixmembered cyclic transition state and cleavage of the C sp2-Csp3 bond. Regioselective esterification and one-pot couversion of silyl ethers into esters with good yields was observed. Simple reaction conditions, high yields, and broad scope of the reaction illustrate the good synthetic utility of this method.
Rao, Chitturi Bhujanga,Rao, Dasireddi Chandra,Babu, Dokuburra Chanti,Venkateswarlu, Yenamandra
supporting information; experimental part
p. 2855 - 2859
(2010/08/05)

Indium-catalyzed synthesis of keto esters from cyclic 1,3-diketones and alcohols and application to the synthesis of seratrodast
Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)3, iron(III) triflate, Fe-(OTf)3, copper(II) triflate, Cu(OTf)2, and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.
Kuninobu, Yoichiro,Kawata, Atsushi,Noborio, Taihei,Yamamoto, Syun-Ichi,Matsuki, Takashi,Takata, Kazumi,Takai, Kazuhiko
experimental part
p. 941 - 945
(2010/07/07)

An efficient iron-catalyzed carbon-carbon single-bond cleavage via retro-claisen condensation: A mild and convenient approach to synthesize a variety of esters or ketones
An efficient iron-salt-catalyzed carbon-carbon bond cleavage occurring through a retro-Claisen condensation reaction has been developed. The reaction is useful for the synthesis of a variety of esters or ketones under mild conditions. This method works under solvent-free conditions without the need of an inert atmosphere. This protocol is also applicable for the one-pot syntheses of ketones through tandem carbon-carbon bond formation (substitution or Michael) followed by a retro-Claisen reaction. However, for Michael adducts, ring annulation takes place subsequently. Notably, this method is very simple, convenient, high yielding, and only a catalytic (5 to 1.0 mol-%) amount of Fe(OTf)3 is needed.
Biswas, Srijit,Maiti, Sukhendu,Jana, Umasish
supporting information; experimental part
p. 2861 - 2866
(2010/08/05)

New reactions of anticancer-platinum complexes and their intriguing behaviour under various experimental conditions
The anticancer platinum complexes here described react with organic substrates (such as acids, alkenes, alkynes) and catalyze transformations that can occur in biomolecules which contain unsaturated functions. We have analyzed the role of the platinum complexes in the observed reactions and studied the progress of the detected transformations upon variation of the reaction conditions. The Royal Society of Chemistry 2010.
Aleman, Jose,Del Solar, Virginia,Cubo, Leticia,Quiroga, Adoracion G.,Navarro Ranninger, Carmen
scheme or table
p. 10601 - 10607
(2011/01/05)

Oxidative cleavage of cycloalkanones with dioxygen catalyzed by supported catalysts or homogeneous systems: Evidence for novel active ruthenium (II) and/or (III) species
α-Substituted cycloalkanones are oxidized to oxo-acids by low-nuclearity complexes (Cu2+ or [VO2] +/[VO]2+ - exchanged Nafion beads), or homogeneous systems with ruthenium acetate complexes and [Ru(H 2O)6] (tosylate)2 in dioxygen (0.1 MPa) at 55-60 °C. The catalytic procedures compare well with previously described systems involving homogeneous catalysis with copper (II) or polyoxometalates such as "H8[PMo7V5O40] ·aq". The results complement the widely used oxidative methods for ketone cleavage in cases when protons and transition metal salts are involved. A tentative dioxygenase mechanism, involving peroxygen species, is proposed for these reactions.
Vennat, Maxence,Brégeault, Jean-Marie
scheme or table
p. 9 - 15
(2011/01/03)

Catalytic oxidative cleavage of olefins by RuO4 organic solvent-free under ultrasonic irradiation
All the works reported about oxidative cleavage of olefins by the RuCl3/NaIO4 catalytic system have been performed in biphasic water/organic solvent(s). The first organic solvent-free oxidation of C{double bond, long}C double bond by 2% RuCl3/4.1 equiv NaIO4/H2O is described here using both the emulsifier Aliquat 336 and 20 kHz ultrasonic irradiation.
Rup, Sandrine,Sindt, Michèle,Oget, Nicolas
scheme or table
p. 3123 - 3126
(2010/08/07)

Lodomesitylene-catalyzed oxidative cleavage of carbon-carbon double and triple bonds using m-chloroperbenzoic acid as a terminal oxidant
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Miyamoto, Kazunori,Ochiai, Masahito,Sei, Yoshihisa,Yamaguchi, Kentaro
supporting information; scheme or table
p. 1382 - 1383
(2009/07/24)

Evidence from mechanistic probes for distinct hydroperoxide rearrangement mechanisms in the intradiol and extradiol catechol dioxygenases
Three mechanistic probes were used to investigate whether the Criegee rearrangement step of catechol 1,2-dioxygenase (CatA) from Acinetobacter sp. proceeds via a direct 1,2-acyl migration, via homolytic O-O cleavage, or via a benzene oxide-oxepin rearrangement. Incubation of CatA with 3- chloroperoxybenzoic acid led to the formation of a 9:1 mixture of 2-chlorophenol and 3-chlorophenol, via a mechanism involving O-O homolytic cleavage. Incubation of CatA with 2-hydroperoxy-2-methylcyclohexanone led to formation of 5,6-diketoheptan-1-ol, also consistent with an O-O homolytic cleavage mechanism, and not consistent with a direct 1,2-acyl migration. No reaction product was isolated from incubation of CatA with 6-hydroxymethyl-6-methylcyclohexa-2,4- dienone, an analogue that is able to undergo the benzene oxide-oxepin rearrangement, but not able to undergo O-O homolytic cleavage. In contrast, incubation of extradiol dioxygenase MhpB from Escherichia coli with 6-hydroxymethyl-6-methylcyclohexa2,4-dienone led to the formation of a 2-tropolone ring expansion product, consistent with a direct 1,2-alkenyl migration for extradiol cleavage. Taken together, the results imply different mechanisms for the Criegee rearrangement steps of intradiol and extradiol catechol dioxygenases: a direct 1,2-alkenyl migration for extradiol cleavage and an O-O homolytic cleavage mechanism for intradiol cleavage.
Xin, Meite,Bugg, Timothy D. H.
experimental part
p. 10422 - 10430
(2009/02/04)

Indium(III) chloride-catalyzed oxidative cleavage of carbon-carbon multiple bonds by tert-butyl hydroperoxide in water-a safer alternative to ozonolysis
An efficient and general method for the oxidative cleavage of alkenes and alkynes using tert-butyl hydroperoxide and indium(III) chloride as catalyst in water to give the corresponding carboxylic acids or ketones has been achieved. The reaction conditions are compatible with sensitive moieties such as peptide bonds, tert-butyl carboxylic esters and N-Boc-protected tryptophan. The catalyst could be recycled.
Ranu, Brindaban C.,Bhadra, Sukalyan,Adak, Laksmikanta
p. 2588 - 2591
(2008/09/21)

METHOD FOR PRODUCING CARBOXYLIC ACID AND METHOD FOR CLEAVING BOND OF CARBONYL COMPOUND
PROBLEM TO BE SOLVED: To provide a method for producing a carboxylic acid, capable of reducing the generation of by-products and environment-polluting substances in the production of the carboxylic acid, and a method for cleaving the bond of a carbonyl compound. SOLUTION: This method for generating the carboxylic acid and/or a ketone is provided by performing the reaction of the carbonyl compound with a vanadium-based catalyst in a carboxylic acid solvent under oxygen atmosphere to cleave the bond of the carbonyl compound.
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(2008/06/13)

Synthesis of biologically active substances based on phenoxyethanol derivatives
By reaction of phenoxyethanol with diverse structure acyl chlorides phenoxyethanol esters were synthesized containing in the molecule fragments of undecene acid and also of some ketocarboxylic acids. The latter acids were obtained by ozonation of alkylcyclenes. 2005 Pleiades Publishing, Inc.
Kukovinets,Yamansarova,Kasradze,Lozhkina,Zainullin,Abdullin
p. 673 - 677
(2007/10/03)

Efficient oxidation of cycloalkanols by sodium nitrite with molecular oxygen in trifluoroacetic acid
Oxidation of aliphatic cycloalkanols by sodium nitrite in trifluoroacetic acid gave α,ω-dicarboxylic acids in good yields. Adipic acid was obtained in a quantitative yield from cyclohexanol using 1 equiv of sodium nitrite under oxygen atmosphere but the oxidation required more than 3 equiv of sodium nitrite under nitrogen atmosphere. The oxidation method was applicable to the conversion of 1-alkanols to the corresponding carboxylic acids.
Matsumura, Yoshihiro,Yamamoto, Yutaka,Moriyama, Noriaki,Furukubo, Shigeru,Iwasaki, Fumiaki,Onomura, Osamu
p. 8221 - 8224
(2007/10/03)

Ozonolysis of methylcyclohexanols and methylcyclohexanones
Ozonolysis of isomeric methylcyclohexanols and methylcyclohexanones was studied.
Syroezhko,Begak
p. 102 - 105
(2007/10/03)

Ozonolysis of 1-methylcyclohexanol
The kinetic features and composition of products of 1-methylcyclohexanol ozonolysis were studied.
Syroezhko,Begak
p. 962 - 966
(2007/10/03)

Vanadium-catalysed aerobic cleavage of C-C bonds in substituted cyclohexanones to afford carboxylic acids: Two model complexes with tetrahedral geometry around vanadium(V)
Two monosilanol/disilanol derivatives were synthesised by treatment of Ph3SiOH or Ph2Si(OH)2 with [nBu4N]VO3 (3) in ethanol solution. The mononuclear anionic dioxo vanadium(v) species [{Ph3SiO}2VO2]- (4) and the dinuclear complex anion [{Ph2SiO2VO2}2]2- (5) thus obtained are unusual and novel model compounds with ≡Si-O-V(O)2O linkages characterised by single-crystal X-ray diffraction. The catalytic activities of these tert-butylammonium complexes, together with those of the simple vanadium derivatives 3 and 5, of the vanadyl precursors VOSO4·5H2O (1) and [VO(acac)2] (2), and also of "H6[PMo9V3O40] ·aq", were tested for aerobic C-C bond cleavage in 2-hydroxycyclohexanone and 2-methylcyclohexanone. Monomeric vanadium species show the same chemistry as the polyoxometalate but with lower yields of acids or keto acids, and so the redox and acid properties of HPA-n (n = 3, 4) are better tuned. Mechanisms for these oxidation reaction, including electron transfer from a substrate coordinated to vanadium, are proposed. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
Vennat, Maxence,Herson, Patrick,Bregeault, Jean-Marie,Shul'pin, Georgiy B.
p. 908 - 917
(2007/10/03)

Osmium tetroxide-promoted catalytic oxidative cleavage of olefins: An organometallic ozonolysis
A mild, organometallic alternative to ozonolysis utilizing oxone and OsO4 is presented. This is a direct oxidation of olefins via the carbon-carbon cleavage of an osmate ester by the action of oxone. Twenty-four different olefins were converted to their corresponding ketones or carboxylic acids in high yields (> 80%). Free alcohols, acetate- and benzyl-protected alcohols, and 1,2-diols were stable under these conditions. This method should be applicable for traditional organic synthesis. Copyright
Travis, Benjamin R.,Narayan, Radha S.,Borhan, Babak
p. 3824 - 3825
(2007/10/03)

Oxidation of 2-substituted cycloalkanones with cerium(IV) sulfate tetrahydrate in alcohols and acetic acid
The reaction of 2-substituted cycloalkanones with cerium(IV) sulfate tetrahydrate (CS) in alcohols and acetic acid gave the corresponding alkyl esters of oxo acids (80-96%) and oxo acids (78-96%), respectively, by oxidative cleavage of the C(R).C=O bond. In the case of 2-iodocycloalkanones in methanol, the dimethyl ester was obtained in good yield. A treatment of 5α-cholestan-3-one with CS in methanol produced 2-acetal 3-ester of 2,3-seco derivative in good yield. The effects of cerium(IV) and copper(II) salts are also discussed.
He, Liangyou,Horiuchi, C. Akira
p. 2515 - 2521
(2007/10/03)

Heterogeneously catalysed cleavage of carbon-carbon double bonds with hydrogen peroxide using calcined heteropolyacids on oxide supports
Reaction of an alkene with aqueous hydrogen peroxide and a catalytic quantity of a heteropolyacid adsorbed onto magnesium, aluminium or zinc oxide leads to complete, rapid cleavage of the alkene to give carbonyl compounds.
Brooks, Christopher D.,Huang, Ling-Chu,McCarron, Moya,Johnstone, Robert A. W.
p. 37 - 38
(2007/10/03)

Efficient oxidative cleavage of olefins to carboxylic acids with hydrogen peroxide catalyzed by methyltrioctylammonium tetrakis(oxodiperoxotungsto)phosphate(3-) under two-phase conditions. Synthetic aspects and investigation of the reaction course
The oxidative cleavage of alkenes to carboxylic acids with 40% w/v aqueous hydrogen peroxide catalyzed by methyltrioctylammonium tetrakis(oxodiperoxotungsto)phosphate(3-) (1a) is reported to occur in high yields and selectivities under two-phase conditions in the absence of organic solvents. On the basis of a study of the reaction, two main reaction pathways leading to acids have been recognized, the first one involving the perhydrolysis and the second one the hydrolysis of the epoxide initially formed. The "perhydrolytic" reaction pathway appears to play a primary role in the oxidation of medium- and long-chain alkenes to acids, while it intervenes to a rather limited extent in the oxidation of arylalkenes and C5-C7 cycloalkenes. The occurrence of this pathway has been proved by the isolation of the intermediate β-hydroperoxy alcohols and their transformation into acids with H2O2 and la. The course of this transformation, involving an initial oxidation (to α-oxo hydroperoxide) or decomposition (to carbonyl compounds) of the β-hydroperoxy alcohol intermediate, is described. The primary oxidation products, α-hydroperoxy ketones, have been isolated in the case of internal β-hydroperoxy alcohols, whereas their presence has been evidenced with terminal β-hydroperoxy alcohols bearing a secondary hydroxy group. Hydrogen peroxide concentration appears to exert a remarkable influence on medium acidity, and its effects on the reaction efficiency are shown.
Antonelli, Ermanno,D'Aloisio, Rino,Gambaro, Mario,Fiorani, Tiziana,Venturello, Carlo
p. 7190 - 7206
(2007/10/03)

Oxidation reactions catalysed by titanium- and chromium-containing silicalites
While the titanium silicalite-1 (TS-1)-tert-butyl hydroperoxide (TBHP) combination exhibits remarkable activity and selectivity in the oxidative cleavage of the C-C double bond of silyl enol ethers to produce dicarboxylic acids, the chemoselective oxidation of thioethers to sulfoxides without generation of sulfones is achieved using chromium silicalite-2 (CrS-2)-H2O2.
Raju, Satya V. N.,Upadhya,Ponrathnam,Daniel,Sudalai
p. 1969 - 1970
(2007/10/03)

Alkane oxidation with molecular oxygen using a new efficient catalytic system: N-hydroxyphthalimide (NHPI) combined with Co(acac)n (n = 2 or 3)
A novel class of catalysts for alkane oxidation with molecular oxygen was examined. N-Hydroxyphthalimide (NHPI) combined with Co(acac)n (n = 2 or 3) was found to be an efficient catalytic system for the aerobic oxidation of cycloalkanes and alkylbenzenes under mild conditions. Cycloalkanes were successfully oxidized with molecular oxygen in the presence of a catalytic amount of NHPI and Co(acac)2 in acetic acid at 100°C to give the corresponding cycloalkanones and dicarboxylic acids. Alkylbenzenes were also oxidized with dioxygen using this catalytic system. For example, toluene was converted into benzoic acid in excellent yield under these conditions. Ethyl- and butylbenzenes were selectively oxidized at their α-positions to form the corresponding ketones, acetophenone, and 1-phenyl-1-butanone, respectively, in good yields. A key intermediate in this oxidation is believed to be the phthalimide N-oxyl radical generated from NHPI and molecular oxygen using a Co(II) species. The isotope effect (kH/kD) in the oxidation of ethylbenzene and ethylbenzene-d10 with dioxygen using NHPI/Co(acac)2 was 3.8.
Ishii, Yasutaka,Iwahama, Takahiro,Sakaguchi, Satoshi,Nakayama, Kouichi,Nishiyama, Yutaka
p. 4520 - 4526
(2007/10/03)

Problems in Selective Catalysis with Molecular Imprints in Silica - Selective Lactones Formation from Hydroxyesters in Micropores
Selective lactone formation from hydroxy esters can be obtained with microporous glass catalysts.By a sol-gel polycocondensation of TEOS and a cyclic phosphonate an imprinted microporous silica catalyst was prepared.The imprint molecule selected is a transition state analogue for the lactone formation from hydroxy esters.Although selective γ- and δ-lactone formation from the respective hydroxy esters was observed, control experiments revealed, that the catalytic selectivity of the lactone formation is already obtained by the micropores of the material and not associated to the imprint.The study illustrates the importance of proper control experiments for the evaluation of imprint effects in selectively catalyzed reactions. - Keywords: Micropores, Selective Lactones Formation, Silica Catalyst
Heilmann, Jens,Maier, Wilhelm F.
p. 460 - 468
(2007/10/02)

Les heteropolyacides comme catalyseurs bifonctionnells pour la coupure oxydante de cyclanones
In the presence of dioxygen, heteropolyacids "H(3+n),aq" (HPA-n; n = 1-4), react with cyclanones to afford carboxylic acids.Treatment of 2-methylcyclohexanone gives 6-oxoheptanoic acid in high yields.Reaction of cyclohexanone with "HPA-n/AcOH-H2O/O2" systems affords adipic acid, glutaric acid, succinic acid and carbon dioxide.The byproducts arise predominantly by 6-oxohexanoic acid degradation.The reaction of hydrogen peroxide with molybdenum trioxide, vanadium(V) oxide and orthophosphoric acid has been studied and the formation of HPA-n has been obtained at room temperature in a short time. - Keywords: catalytic oxidation, cycloalkanones, heteropolyacids, dioxygen
Atlamsani, A.,Ziyad, M.,Bregeault, J. M.
p. 1344 - 1364
(2007/10/02)

Oxidation of 2-Methylcyclohexanone and Cyclohexanone by Dioxygen Catalyzed by Vanadium-Containing Heteropolyanions
2-Methylcyclohexanone is oxidized by dioxygen in the presence of H(3+n)*aq to give 6-oxoheptanoic acid.Solvent effects are studied.The same precursors with cyclohexanone in aqueous acetic acid give adipic acid as the major product and other dicarboxylic acids by oxidation of 6-oxohexanoic acid.
Atlamsani, Ahmed,Bregeault, Jean-Marie,Ziyad, Mahfoud
p. 5663 - 5665
(2007/10/02)

Use of Formic or Oxalic Acid for the Regioselective Hydrocarboxylation of Alkenes and Alkynes Catalyzed by Pd/C and 1,4-Bis(diphenylphosphino)butane
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Ali, B. El,Vasapollo, G.,Alper, H.
p. 4739 - 4741
(2007/10/02)

Synthesis of 5- and 6-oxoalkanoic acids by copper(II) catalyzed oxidative cleavage of cycloalkanones with dioxygen
α-Substituted cycloalkanones are oxidized to oxo acids by the copper(II)/dioxygen/acetic acid/water system. This catalytic procedure compares well with the previously described systems involving vanadium precursors.
Atlamsani,Bregeault
p. 79 - 81
(2007/10/02)

Cobalt(II) Complex Catalyzed Epoxidation of Olefins by Combined Use of Molecular Oxygen and Cyclic Ketones
In the presence of a catalytic amount of cobalt(II)-Schiff base complexes, various olefins are smoothly oxygenated into the corresponding epoxides in good to high yields by combined use of an atmospheric pressure of oxygen (oxidant) and cyclic ketones (reductant), such as 2-methylcyclohexanone, under mild conditions.
Takai, Toshihiro,Hata, Eiichiro,Yorozu, Kiyotaka,Mukaiyama, Teruaki
p. 2077 - 2080
(2007/10/02)

Homoenolic radical derived from propionic acid: A versatile reagent for the radical version of the Michael reaction
The homoenolic radical, derived from 3-iodopropionic acid (1) by reaction with in situ generated tributyltin hydride, undergoes clean carbon-carbon forming reaction with electrophilic olefins (2) yielding functionalized acids (3).
Foubelo,Lloret,Yus
p. 9531 - 9536
(2007/10/02)

Reactions of Ozone with 1-Methylcyclohexene and Methylenecyclohexane in Air
Reactions of ozone with 1-methylcyclohexene and methylenecyclohexane were studied for the purpose of obtaining the reaction mechanism as a prototype of the reaction of ozone with pinenes.The similarity of the yields of corresponding gaseous products between 1-methylcyclohexene and α-pinene and between methylenecyclohexane and β-pinene indicates the similarity of the reaction mechanisms.
Hatakeyama, Shiro,Akimoto, Hajime
p. 2701 - 2703
(2007/10/02)

Oxidative Cleavage of Vicinal Diols at the Nickel Hydroxide Electrode
Vicinal diols are oxidatively cleaved with good yields by electrolysis at an oxide covered nickel electrode in an aqueous alkaline electrolyte and an undivided cell.The method is applied in the synthesis of optical pure derivatives of 2,2-dimethyl-1,3-dioxolane-4-carboxylic acid.
Ruholl, Heinrich,Schaefer, Hans J.
p. 54 - 56
(2007/10/02)

MoO2 (acac)2 Complex as a Reagent for Oxidative Cleavage of vic-Diols
MoO2(acac)2-t-BuOOH system has high activity for oxidative cleavage of tertiary and secondary vic-diols.MoO2(acac)2 cleaves the diols to give carbonyl compounds in the absence of t-BuOOH.
Kaneda, Kiyotomi,Morimoto, Kenichi,Imanaka, Toshinobu
p. 1295 - 1296
(2007/10/02)

Hydrogen Peroxide Oxidation Catalyzed by Heteropoly Acids Combined with Cetylpyridinium Chloride: Epoxidation of Olefins and Allylic Alcohols, Ketonization of Alcohols and Diols, and Oxidative Cleavage of 1,2-Diols and Olefins
A general and versatile oxidation catalyst has been developed by using hydrogen peroxide as the oxidant.Olefins and allylic alcohols were epoxidized with commercially available hydrogen peroxide (30-35percent H2O2) using a combination of Mo- or W-based heteropoly acids, H3PMo12O40 (MPA) or H3PW12O40 (WPA), with an appropriate ammonium salt such as cetylpyridinium chloride (CPC), under two-phase conditions using chloroform as the solvent (Tables I and II).The tris(cetylpyridinium) 12-tungtophosphate (CWP), +(CH2)15CH3>3(PW12O40)3-, prepared independently from WPA and 3 equiv of CPC, catalyzes the efficient ketonization of the secondary hydroxy group of alcohols and diols with H2O2 under homogeneous conditions using tert-butyl alcohol as the solvent (Table III).Under the same conditions, oxidative cleavage of vic-diols was successfully conducted by the CWP-H2O2 system to give carboxylic acids in good yields (Table IV).This catalyst-oxidant system was also efficient for the oxidative cleavage of carbon-carbon double bonds of olefins which provides a new valuable conversion of olefins to carboxylic acids (Table V).
Ishii, Yasutaka,Yamawaki, Kazumasa,Ura, Toshikazu,Yamada, Hiroshi,Yoshida, Tsutomu,Ogawa, Masaya
p. 3587 - 3593
(2007/10/02)