- Rapid, chemoselective and mild oxidation protocol for alcohols and ethers with recyclable N-chloro-N-(phenylsulfonyl)benzenesulfonamide
-
Chlorine is the 20th most abundant element on the earth compared to bromine, iodine, and fluorine, a sulfonimide reagent, N-chloro-N-(phenylsulfonyl)benzenesulfonamide (NCBSI) was identified as a mild and selective oxidant. Without activation, the reagent was proved to oxidize primary and secondary alcohols as well as their symmetrical and mixed ethers to corresponding aldehydes and ketones. With recoverable PS-TEMPO catalyst, selective oxidation over chlorination of primary and secondary alcohols and their ethers with electron-donating substituents was achieved. The reagent precursor of NCBSI was recovered quantitatively and can be reused for synthesizing NCBSI.
- Badani, Purav,Chaturbhuj, Ganesh,Ganwir, Prerna,Misal, Balu,Palav, Amey
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supporting information
(2021/06/03)
-
- SBA-15 Supported 1-Methyl-2-azaadamanane N-Oxyl (1-Me-AZADO) as Recyclable Catalyst for Oxidation of Alcohol
-
Herein, we designed and synthesized an SBA-15 supported 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO) and investigated its catalytic performance for selective oxidation of alcohols under Anelli's conditions. The first example of immobilization of 1-Me-AZADO was very important to advance the oxgenation effectively because this supported N-oxyl has excellent catalytic activity for oxidation of alcohols to carbonyl compounds, and more importantly, it can be conveniently recovered and reused at least 6 times without significant effect on its catalytic efficiency.
- Tian, Yangwu,Guo, Xiaqun,Li, Meichao,Li, Chunmei,Hu, Xinquan,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu
-
supporting information
p. 3928 - 3932
(2021/05/26)
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- Method of preparing L-menthone from R-citronellal
-
The invention discloses a method of preparing L-menthone from R-citronellal. Under the action of a Pd-Co-MOF-MMT catalyst, R-citronellal carries out heterogeneous catalytic reactions to generate L-menthone, the conversion rate of R-citronellal can reach 90-99.9%, the yield of L-menthone can reach 85-98%, and the ee value of menthone can reach 95-99.99%.
- -
-
Paragraph 0075-0092
(2020/04/06)
-
- Method for preparation of L-menthone from R-citronellal
-
The invention discloses a method for preparation of L-menthone from R-citronellal. In the presence of a Ru-Cu-MOF catalyst, R-citronellal is cyclized to prepare L-menthone, the reaction conditions aremild, the reaction enantioselectivity is 90%-99.5%, the conversion rate can reach 95%-99.9%, and the ee value of menthone can reach 90%-99.9%.
- -
-
Paragraph 0076-0093
(2020/04/02)
-
- Chemoselective Hydrogenation of α,β-Unsaturated Carbonyls Catalyzed by Biomass-Derived Cobalt Nanoparticles in Water
-
Herein, we report highly chemoselective hydrogenation of α,β-unsaturated carbonyls to saturated carbonyls catalyzed by cobalt nanoparticles supported on the biomass-derived carbon from bamboo shoots with molecular hydrogen in water, which is the first prototype using a heterogeneous non-noble metal catalyst for such organic transformation as far as we know. The optimal cobalt nanocatalyst, CoOx@NC-800, manifested remarkable activity and selectivity for hydrogenation of C=C in α,β-unsaturated carbonyls under mild conditions. A broad set of α,β-aromatic and aliphatic unsaturated carbonyls were selectively reduced to their corresponding saturated carbonyls in up to 99 % yields with good tolerance of various functional groups. Meanwhile, a new straightforward one-pot cascade synthesis of saturated carbonyls was realized with high activity and selectivity via the cross-aldol condensation of ketones with aldehydes followed by selective hydrogenation. More importantly, this one-pot strategy is applicable for the expedient synthesis of Loureirin A, a versatile bioactive and medicinal molecule, from readily available starting materials, further highlighting the practical utility of the catalyst. In addition, the catalyst can be easily separated for successive reuses without significant loss in both activity and selectivity.
- Song, Tao,Ma, Zhiming,Yang, Yong
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p. 1313 - 1319
(2019/01/25)
-
- Amino-TEMPO Grafted on Magnetic Multi-Walled Nanotubes: An Efficient and Recyclable Heterogeneous Oxidation Catalyst
-
An efficient and easy recyclable heterogeneous oxidation catalyst was prepared by grafting TEMPO–NH2 moieties on the surface of magnetic multi-walled carbon nanotubes (MWCNT), first by a radical reaction introducing butyric acid moieties on carbon nanotube surface. Subsequently, carboxylic acid moieties were submitted for amidation using TEMPO–NH2. The functionalized nanotubes [MWCNT-{(CH2)3-CO-NH-TEMPO}n] were investigated as a (pre-)catalyst for the oxidation of primary and secondary alcohols for the production of aldehydes and ketones in a Montanari-type catalytic oxidation using the cheap and readily available 1,3-dichloro-5,5-dimethylhydantoin as the terminal oxidant.
- Gambarotti, Cristian,Bj?rsvik, Hans-René
-
p. 1405 - 1412
(2019/01/04)
-
- Cyclopropenium-Activated DMSO for Swern-Type Oxidation
-
Swern oxidation is widely used to convert alcohols into their corresponding carbonyl compounds. However, the conventional method with use of the volatile oxalyl chloride as an activator requires the reaction to be conducted below -60 °C. We discovered that 3,3-dichloro-1,2-diphenylcyclopropene (DDC) can be used as a new activator for Swern-type oxidations of alcohols, which can be conducted at -20 °C. This new protocol features mild and fast reactions with easy operation. Furthermore, the activator DDC is easy to handle, and diphenylcyclopropenone can be recovered quantitively. This new type of Swern oxidation shows a broad scope of substrates including benzylic, allylic, aliphatic, and biobased alcohols, and gives high yields of up to 93%.
- Guo, Tianfo,Gao, Yu,Li, Zhenjiang,Liu, Jingjing,Guo, Kai
-
supporting information
p. 329 - 332
(2019/02/12)
-
- A rapid and convenient oxidation of secondary alcohols
-
A rapid (normally 20?min to 2?h) and selective oxidation of secondary alcohols to ketones can be achieved using 0.4?equivalents trichloroisocyanuric acid and 1.2?equivalents pyridine at room temperature in ethyl acetate. A likely mechanism for the reaction is proposed.
- Dip, Irene,Gethers, Christina,Rice, Tonya,Straub, Thomas S.
-
supporting information
p. 2720 - 2722
(2017/06/23)
-
- Cooperative Electrocatalytic and Chemoselective Alcohol Oxidation by Shvo's Catalyst
-
A new electrocatalytic conversion of alcohols to ketones and aldehydes was developed based on an electrochemical study of Shvo's complex. The oxidation of secondary alcohols was efficiently performed under mild conditions using a catalytic amount of Shvo's catalyst, in combination with a sub-stoichiometric amount of 2,6-dimethoxy-1,4-benzoquinone in N,N-dimethylformamide at 80 °C. The hydroquinone thus formed is continuously reoxidized with the aid of an electrochemical device. Excellent yields for different ketones, aromatic as well as aliphatic and α,β-unsaturated ketones, are obtained. In addition, chemoselectivity towards oxidation of the secondary alcohol is achieved when converting vicinal diols such as 1,2-octanediol and 1,2-decanediol. (Figure presented.).
- Lybaert, Jeroen,Trashin, Stanislav,Maes, Bert U. W.,De Wael, Karolien,Abbaspour Tehrani, Kourosch
-
supporting information
p. 919 - 925
(2017/03/27)
-
- Secondary Phosphine Oxides as Multitalented Preligands En Route to the Chemoselective Palladium-Catalyzed Oxidation of Alcohols
-
Secondary phosphine oxides O=PHR2 (SPOs) were identified as multitalented preligands for the chemoselective Pd-catalyzed oxidation of alcohols by a hydrogen-abstracting methodology. SPOs were found to promote the hydrogen-abstraction step as well as hydrogen transfer to a Michael acceptor by generating a putative active H?Pd species. The catalytic system operates under neutral conditions and was proven to be compatible with various electrophilic and nucleophilic functionalities within the substrates as well as water- and air-sensitive functional groups.
- Vasseur, Alexandre,Membrat, Romain,Gatineau, David,Tenaglia, Alphonse,Nuel, Didier,Giordano, Laurent
-
p. 728 - 732
(2017/03/13)
-
- Heterogeneous Ru(iii) oxidation catalysts: Via 'click' bidentate ligands on a periodic mesoporous organosilica support
-
A 100% monoallyl ring-type Periodic Mesoporous Organosilica (PMO) is prepared as a novel, versatile and exceptionally stable catalytic support with a high internal surface area and 5.0 nm pores. Thiol-ene 'click' chemistry allows straightforward attachment of bifunctional thiols (-NH2, -OH, -SH) which, exploiting the thioether functionality formed, give rise to 'solid' bidentate ligands. [Ru(acac)2(CH3CN)2]PF6 is attached and complex formation on the solid is studied via density functional theory. All resulting solid catalysts show high activity and selectivity in alcohol oxidation reactions performed in green conditions (25 °C/water). The PMO catalysts do not leach Ru during reaction and are thus easily recuperated and re-used for several runs. Furthermore, oxidation of poorly water-soluble (±)-menthol illustrates the benefits of using hydrophobic PMOs as catalytic supports.
- Clerick, Sander,De Canck, Els,Hendrickx, Kevin,Van Speybroeck, Veronique,Van Der Voort, Pascal
-
p. 6035 - 6045
(2018/06/06)
-
- Photoinduced Oxidation of Secondary Alcohols Using 4-Benzoylpyridine as an Oxidant
-
Photoinduced oxidation of secondary alcohols to ketones was achieved by utilizing an equimolar amount of 4-benzoylpyridine as an oxidant. This transformation proceeds at ambient temperature and exhibits high compatibility with polar functionalities including benzoyl, silyl, and methoxymethyl alcohol protecting groups as well as tosyloxy, bromo, sulfonyl, carbamate, ester, and carboxylic acid units. The present oxidation is solely promoted by the action of organic molecules without the aid of metallic reagents. (Chemical Equation Presented).
- Kamijo, Shin,Tao, Keisuke,Takao, Go,Tonoda, Hiroshi,Murafuji, Toshihiro
-
supporting information
p. 3326 - 3329
(2015/07/15)
-
- Solar photochemical oxidation of alcohols using catalytic hydroquinone and copper nanoparticles under oxygen: Oxidative cleavage of lignin models
-
Alcohols are converted into to their corresponding carbonyl compounds using catalytic amounts of 1,4-hydroquinone with a copper nanoparticle electron transfer mediator with oxygen as the terminal oxidant in acetone as solvent under visible light irradiation. These conditions employing biorenewable hydroquinone as reagent were developed from initial experiments using stoichiometric amounts of 1,4-benzoquinone as oxidant. A range of benzylic and aliphatic primary and secondary alcohols are oxidized, affording the corresponding aldehydes or ketones in moderate to excellent yields. The methodology is also applicable to the oxidative degradation of lignin model compounds that undergo C-C bond cleavage to give simple aromatic compounds.
- Mitchell, Lorna J.,Moody, Christopher J.
-
p. 11091 - 11100
(2015/01/08)
-
- 2-Iodoxybenzenesulfonic acid-catalysed oxidation of primary and secondary alcohols with oxone in cetyl trimethylammonium bromide micelles at room temperature
-
A mild and green protocol for alcohol oxidation using 2-iodoxybenzene sulfonic acid/oxone at room temperature in CTAB micelles has been developed. Typically, secondary benzyl alcohols were oxidised to ketones and primary benzyl alcohols to aldehydes in good yields in 2 h. Under harsher conditions (100 °C/24 h), aliphatic alcohols were oxidised to ketones or organic acids in moderate to high yields.
- Liu, Yangyang,Wang, Boliang
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p. 427 - 431
(2014/08/05)
-
- 3,4-Dihydroisoquinolinium trichloroacetatochromate: A mild and effective new reagent for oxidation of alcohols to carbonyl compounds and arenes to their quinones
-
A new chromium(VI) reagent, 3,4-dihydroisoqinolinium trichloroacetatochromate was prepared by reacting trichloroacetic acid with CrO3in water. This reagent is suitable to oxidize various primary and secondary alcohols to the corresponding carbonyl compounds and anthracene to antraquinone in a good yields.
- Ozen, Recep
-
p. 6081 - 6083
(2015/02/19)
-
- ALPHA-HYDROGEN SUBSTITUTED NITROXYLS AND DERIVATIVES THEREOF AS CATALYSTS
-
The present invention relates to novel alpha-hydrogen substituted nitroxyl compounds and their corresponding oxidized (oxoammonium cations) and reduced (hydroxylamine) forms, and to the use of such compounds, inter alia, for (1) oxidation of primary and secondary alcohols to aldehydes and ketones, respectively; (2) resolution of racemic alcohols; (3) desymmetrization of meso-alcohol; (4) as radicals and spin trapping reagents; and (5) as polymerization agents. The present invention further relates to processes for preparing the novel nitroxyl/oxoammonium/ hydroxylamine compounds from the corresponding amines, and to certain novel amine derivatives and their uses. The compounds of the invention as well as the amine precursors are also useful as ligands for transition metals and as organocatalysts in e.g., aldol reactions.
- -
-
Page/Page column 37
(2013/08/28)
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- Development of the first menthane-based chiral bis(π-allylpalladium) catalysis: Asymmetric allylation of imines
-
A new ethylidene menthane-based chiral π-allylpalladium complex catalyzes the asymmetric allylation of various imines with allyltributylstannane and 1 equiv. of water to give chiral homoallylamines in good yields and enantioselectivities. The reaction was carried out essentially under neutral conditions and displayed a good transfer of chiral information from the menthane skeleton through the formation of a bis(π-allylpalladium) species. This is the first example of menthane-based chiral bis(π-allylpalladium) catalysis. A menthane-based chiral π-allylpalladium-catalyzed asymmetric allylation of various imines has been developed giving chiral homoallylamines in good yields and enantioselectivities. The reaction displays a good transfer of chiral information from the menthane skeleton through the formation of a bis(π-allylpalladium) complex. Copyright
- Fernandes, Rodney A.,Chaudhari, Dipali A.
-
scheme or table
p. 1945 - 1952
(2012/05/20)
-
- Nicotinamide-dependent Ene reductases as alternative biocatalysts for the reduction of activated alkenes
-
Four NAD(P)H-dependent non-flavin ene reductases have been investigated for their ability to reduce activated C=C bonds in an asymmetric fashion by using 20 structurally diverse substrates. In comparison with flavin-dependent Old Yellow Enzyme homologues, a higher degree of electronic activation was required, because the best activities were obtained with enals and nitroalkenes rather than enones and carboxylic esters. Although FaEO from Fragaria x ananassa (strawberry) and its homologue SlEO from Solanum lycopersicum (tomato) exhibited a narrow substrate spectrum, progesterone 5β-reductase (At5β-StR) from Arabidopsis thaliana (thale cress) and leukotriene B4 12-hydroxydehydrogenase (LTB4DH/PGR) from Rattus norvegicus (rat) appear to be promising candidates, in particular for the asymmetric bioreduction of open-chain enals, nitroalkenes and α,β-unsaturated γ-butyrolactones. Competing nitro reduction and non-enzymatic Weitz-Scheffer epoxidation were largely suppressed. Electronically activated alkenes have been stereoselectively reduced by using a single-enzyme-cofactor system employing nicotinamide-dependent non-flavin ene reductases. Copyright
- Durchschein, Katharina,Wallner, Silvia,MacHeroux, Peter,Schwab, Wilfried,Winkler, Thorsten,Kreis, Wolfgang,Faber, Kurt
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p. 4963 - 4968
(2013/01/14)
-
- Cyclization of citronellal in a supercritical solvent in a flow reactor in the presence of Al2O3
-
The reactivity of citronellal under supercritical solvent conditions in a flow reactor in the presence of Al2O3 is examined. It is shown that at 160°C, the main transformation product of citronellal is isopulegol, and when the temperature is increased to 190°C, they are monoterpenes with a para-menthane framework and myrcene. Pleiades Publishing, Ltd., 2012.
- Anikeev,Il'Ina,Volcho,Salakhutdinov
-
p. 1917 - 1919
(2013/01/15)
-
- Grafting of oxo-vanadium Schiff base on graphene nanosheets and its catalytic activity for the oxidation of alcohols
-
Graphene oxide was found to be a convenient and efficient supporting material for grafting of oxo-vanadium Schiff base via covalent attachment. The low dimensionality and rich surface chemistry of graphene oxide play critical roles in order to achieve a good degree of such grafting. Catalytic potential of the so prepared graphene-bound oxo-vanadium Schiff base and comparison with its homogeneous analogue was studied for the oxidation of various alcohols to carbonyl compounds using tert-butylhydroperoxide as oxidant. The structural and chemical nature of the catalyst was characterized by a variety of techniques including XRD, FTIR, TGA, TEM, and ICP-AES. The immobilized complex was found to be highly efficient and showed comparable catalytic reactivity as its homogenous analogue with the added benefits of facile recovery and recycling of the heterogeneous catalyst. The graphene-bound oxo-vanadium Schiff base was successfully reused for several runs without significant loss in its catalytic activity. The Royal Society of Chemistry 2012.
- Mungse, Harshal P.,Verma, Sanny,Kumar, Neeraj,Sain, Bir,Khatri, Om P.
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experimental part
p. 5427 - 5433
(2012/06/15)
-
- Twist does a twist to the reactivity: Stoichiometric and catalytic oxidations with twisted tetramethyl-IBX
-
The methyl groups in TetMe-IBX lower the activation energy corresponding to the rate-determining hypervalent twisting (theoretical calculations), and the steric relay between successive methyl groups twists the structure, which manifests in significant solubility in common organic solvents. Consequently, oxidations of alcohols and sulfides occur at room temperature in common organic solvents. In situ generation of the reactive TetMe-IBX from its precursor iodo-acid, i.e., 3,4,5,6-tetramethyl-2-iodobenzoic acid, in the presence of oxone as a co-oxidant facilitates the oxidation of diverse alcohols at room temperature.
- Moorthy, Jarugu Narasimha,Senapati, Kalyan,Parida, Keshaba Nanda,Jhulki, Samik,Sooraj, Kunnikuruvan,Nair, Nisanth N.
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experimental part
p. 9593 - 9601
(2012/01/03)
-
- The oxidation of pyridine and alcohol using the Keggin-type lacunary polytungstophosphate as a temperature-controlled phase transfer catalyst
-
A novel temperature-controlled phase transfer catalyst of [(C 18H37)2(CH3)2N] 7[PW11O39] has been developed for the oxidation of pyridines and alcohols with hydrogen peroxide. The reactions were conducted in 1,4-dioxane, and high yields of the corresponding heterocyclic N-oxides and ketones were obtained under relative mild conditions. The catalyst could be easily recovered and reused after reaction with cooling. There was no discernable loss in activity and selectivity after several reaction cycles.
- Ding, Yong,Zhao, Wei
-
experimental part
p. 45 - 51
(2011/04/24)
-
- Menthone aryl acid hydrazones: A new class of anticonvulsants
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A series of ten compounds (Compounds J1-J10) of (±) 3-menthone aryl acid hydrazone was synthesized and characterized by thin layer chromatography and spectral analysis. Synthesized compounds were evaluated for anticonvulsant activity after intraperitoneal (i.p) administration to mice by maximal electroshock (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure method and minimal clonic seizure test. Minimal motor impairment was also determined for these compounds. Results obtained showed that four compounds out of ten afforded significant protection in the minimal clonic seizure screen at 6 Hz. Compound J6, 4-Chloro-N-(2-isopropyl-5- methylcyclohexylidene) benzohydrazide was found to be the most active compound with MES ED50 of 16.1 mg/kg and protective index (pI) of greater than 20, indicating that (±) 3-menthone aryl acid hydrazone possesses better and safer anticonvulsant properties than other reported menthone derivatives viz. menthone Schiff bases, menthone semicarbazides and thiosemicarbazides.
- Jain, Jainendra,Kumar,Sinha, Reema,Kumar, Rajeev,Stables, James
-
experimental part
p. 56 - 61
(2012/01/11)
-
- Stereocontrolled syntheses of (-)-cubebol and (-)-10-epicubebol involving intramolecular cyclopropanation of a-lithiated epoxides
-
Figure Presented Formylation of (-)-menthone (11) with LDA and HCO 2CH2CF3 avoids loss of configurational integrity at the isopropyl group, giving hydroxymethylenementhone 12. Lithium 2,2,6,6-tetramethylpiperidideinduced intramolecular cyclopropanation of derived unsaturated terminal epoxide 17 (and chlorohydrin 16), efficiently generates a substituted tricyclo[4.4.0.01.5]decan-4-ol 18, which is used in a concise synthesis of (-)-cubebol (1). In contrast, isopropyl group inversion during formylation of menthone with NaOMe and HCO2Et led, by a similar strategy, to syntheses of 7-epicubebol (33) and (from(+)-menthone) of naturally occurring (-)-10-epicubebol (39), confirming the original structural assignment. Computational studies support the origin of the inversion as being rate-determining formylation of cis-enolate 27 from amixture of rapidly interconverting enolates. In the synthesis of 7-epicubebol (33), allylic tertiary C-H insertion is observed as a significant competing reaction in the intramolecular cyclopropanation of unsaturated terminal epoxide 22.
- Hodgson, David M.,Salik, Saifullah,Fox, David J.
-
experimental part
p. 2157 - 2168
(2010/06/17)
-
- Menthone semicarbazides and thiosemicarbazides as anticonvulsant agents
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A series of novel (±) 3-menthone semicarbazides (1-7) and thiosemicarbazides (8-14) were synthesized using an appropriate synthetic route and characterized by thin layer chromatography and spectral analysis. The anticonvulsant activity of synthesized compounds was established after intraperitoneal administration in three seizure models in mice which include maximal electroshock seizure (MES), subcutaneous pentylene tetrazole (scPTZ) induced seizure and minimal neurotoxicity test. Seven compounds exhibited protection in both models and N1 - (4-fluorophenyl) - N4- (menth-3-one) semicarbazide (4) emerged as the most active compound with MES ED50 of 44.15mg/kg and scPTZ ED50 of 38.68mg/kg at 0.25h duration. These compounds were found to elevate γ-amino butyric acid (GABA) levels in the midbrain region, thus indicating that (±) 3-menthone semicarbazides could be considered as a lead molecule in designing of a potent anticonvulsant drug.
- Jain, Endra,Kumar,Stables, James,Sinha, Reema
-
experimental part
p. 44 - 50
(2011/11/12)
-
- 3-Alkyl-p-menthan-3-ol derivatives: synthesis and evaluation of their physiological cooling activity
-
Different 3-alkyl-p-methan-3-ol derivatives provide a strong physiological cooling effect with potential application as food and cosmetic additives. In order to investigate the influence of the chemical structure on the cooling sensation, the stereoselective syntheses of 29 different 3-alkyl-p-methan-3-ol derivatives were accomplished. All the compounds obtained are odorless and were evaluated by taste, considering two sensations: a cooling effect and bitterness. The results of this structure-activity relationship study highlight that compounds with a (1R,4S)-configuration are the isomers with the more intense cooling effect and lower bitterness. In addition, the structure of the 3-alkyl chain affected the latter properties. Increasing the chain length over two carbon atoms does not change the cooling power, but enhances the bitterness with the additional feature that the branched isomers are considerably more bitter than the linear ones. Overall, the 3-alkyl-p-menthan-3-ol isomers with the best quality in terms of high cooling power and low bitterness are (1R,4S)-3-(hydroxymethyl)-p-menthan-3-ol diastereoisomers (-)-38 and (-)-42.
- Fuganti, Claudio,Joulain, Daniel,Maggioni, Francesco,Malpezzi, Luciana,Serra, Stefano,Vecchione, Andrea
-
body text
p. 2425 - 2437
(2009/04/06)
-
- Heteropoly acid-based supported ionic liquid-phase catalyst for the selective oxidation of alcohols
-
A supported ionic liquid strategy has been applied for the immobilization of a heteropolyacid, molybdovanadophosphoric acid, onto ionic liquid-modified mesoporous silica SBA-15. The immobilized catalyst demonstrated high activity in the aerobic oxidation of primary and secondary alcohols to aldehydes and ketones, respectively. No overoxidation of the primary alcohols to carboxylic acids was observed. Secondary alcohols were chemoselectively oxidized to ketones in the presence of primary alcohol, hetero atom, and allyl groups. This catalyst could be recycled five times without obvious loss of activity.
- Bordoloi, Ankur,Sahoo, Suman,Lefebvre,Halligudi
-
experimental part
p. 232 - 239
(2009/03/11)
-
- An enone reductase from Nicotiana tabacum: cDNA cloning, expression in Escherichia coli, and reduction of enones with the recombinant proteins
-
In the course of the purification of enone reductase participating to the reduction of pulegone, two reductases (NtRed-1 and NtRed-2) were isolated from cultured cells of Nicotiana tabacum. The partial amino acid sequences of the reductases revealed that NtRed-1 was allyl-alcohol dehydrogenase (Accession No. BAA89423) and NtRed-2 was malate dehydrogenase (Accession No. CAC12826). cDNA cloning and expression of these reductases in Escherichia coli were performed. Reduction with recombinant proteins was examined with cyclic α,β-unsaturated ketones, such as pulegone, carvone and verbenone, as substrates. It was found that the recombinant NtRed-1 catalyses the hydrogenation of the exocyclic C-C double bond of pulegone.
- Matsushima, Akihito,Sato, Yuya,Otsuka, Miki,Watanabe, Takayoshi,Yamamoto, Hiroaki,Hirata, Toshifumi
-
-
- Tagged hypervalent iodine reagents: A new purification concept based on ion exchange through SN2 substitution
-
(Chemical Equation Presented) The preparation of phenylsulfonate-tagged iodine(III) reagents as well as their use in a novel purification strategy for iodine(III)-promoted reactions is described. The concept is based on ion exchange and is initiated by an azide-promoted SN2-reaction at the alkyl sulfonate followed by trapping of the resulting aryl sulfonate anion with an ion-exchange resin. The concept is successfully proven for Ru-catalyzed oxidations of alcohols, the activation and glycosidatlon of thioglycosides, and the Suarez reaction of pyranoses.
- Kunst, Eike,Gallier, Florian,Dujardin, Gilles,Yusubov, Mekhman S.,Kirschning, Andreas
-
p. 5199 - 5202
(2008/09/17)
-
- Conjugate reduction of α,β-unsaturated carbonyl compounds promoted by nickel nanoparticles
-
The system composed of nickel(II) chloride, lithium metal, a catalytic polymer-supported arene, and ethanol, has been efficiently applied to the conjugate reduction of a variety of α,β-unsaturated carbonyl compounds (ketones and carboxylic acid derivatives) under very mild reaction conditions. Georg Thieme Verlag Stuttgart.
- Alonso, Francisco,Osante, I?aki,Yus, Miguel
-
p. 3017 - 3020
(2008/02/12)
-
- Highly efficient RuCl3-catalyzed disproportionation of (diacetoxyiodo)benzene to iodylbenzene and iodobenzene; leading to the efficient oxidation of alcohols to carbonyl compounds
-
(Diacetoxyiodo)benzene (DIB) selectively oxidizes primary and secondary alcohols to the respective carbonyl compounds in the presence of RuCl3 (0.8-1.0 mol %) at room temperature in aqueous acetonitrile. This reaction proceeds via an initial instantaneous Ru-catalyzed disproportionation of DIB to iodobenzene and iodylbenzene with the latter acting as the actual stoichiometric oxidant toward alcohols.
- Yusubov, Mekhman S.,Chi, Ki-Whan,Park, Joo Yeon,Karimov, Rashad,Zhdankin, Viktor V.
-
p. 6305 - 6308
(2007/10/03)
-
- 1-Deoxy-5-hydroxysphingolipids as new anticancer principles: An efficient procedure for stereoselective syntheses of 2-amino-3,5-diols
-
(Chemical Equation Presented) Enantioselective preparation of the linear homoallylic alcohol I allows efficient formation of the 2-amino-3,5-diol moiety present in several biologically active compounds, including 1-deoxy-5- hydroxysphingosine analogue IV, which has exhibited excellent biological activity against colon cancer. The conversion of I into IV involves a sequence of enantioselective epoxidation of the O-tert-butoxycarbonyl derivative of I, followed by regioselective and stereospecific oxacyclization of II to introduce differentiated oxygens in III.
- Wiseman, John M.,McDonald, Frank E.,Liotta, Dennis C.
-
p. 3155 - 3157
(2007/10/03)
-
- Thiol-catalyzed acyl radical cyclization of alkenals
-
(Chemical Equation Presented) Thiol-catalyzed direct generation of acyl radicals and their intramolecular addition to olefins of alkenals gave 2-substituted five- and six-membered cyclic ketones in reasonably good yields. The combination of odorless tert-dodecanthiol and AIBN or V-40 was the initiator of choice among surveyed radical generators for the cyclization of alkenals. Aldehydes having electron-deficient olefins cyclized more easily than those having unactivated olefins.
- Yoshikai, Kazuya,Hayama, Tomoharu,Nishimura, Katsumi,Yamada, Ken-Ichi,Tomioka, Kiyoshi
-
p. 681 - 683
(2007/10/03)
-
- Insight into the mechanism of oxidative kinetic resolution of racemic secondary alcohols by using manganese(III)(salen) complexes as catalysts
-
The oxidative kinetic resolution of various racemic secondary alcohols with PhI(OAc)2 catalyzed by chiral [MnIII(salen)] complexes in the presence of KBr was studied in a water/organic solvent mixture. The dramatic, synergetic effect of additives, organic solvent, and the substituents of chiral salen ligands on the enantioselectivities of the reactions is reported. Results from UV/Vis spectroscopy and ESI-MS studies provide evidence that these reactions are induced by the formation of a high-valent manganese intermediate.
- Li, Zhen,Tang, Zhong H.,Hu, Xiao X.,Xia, Chun G.
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p. 1210 - 1216
(2007/10/03)
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- Novel Vanadium-Catalyzed Oxidation of Alcohols to Aldehydes and Ketones under Atmospheric Oxygen
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(Matrix presented) Oxidation of alcohols to aldehydes and ketones has been studied in high yields using atmospheric oxygen and a catalytic amount of V 2O5 in toluene under heating (ca. 100°C). Secondary alcohols can be chemoselectively converted into ketones in the presence of primary hydroxy groups.
- Velusamy, Subbarayan,Punniyamurthy
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p. 217 - 219
(2007/10/03)
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- Novel polyaniline-supported molybdenum-catalyzed aerobic oxidation of alcohols to aldehydes and ketones
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(Chemical Equation Presented) Oxidation of alcohols to aldehydes and ketones has been studied in high yields using molecular oxygen and a catalytic amount of 1 in toluene under stirring (ca. 100°C). The reactions of primary alcohols are faster compared to secondary alcohols and the catalyst 1 can be recycled without loss of activity.
- Velusamy, Subbarayan,Ahamed, Muneer,Punniyamurthy
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p. 4821 - 4824
(2007/10/03)
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- Sulfenamide-catalyzed oxidation of primary and secondary alcohols with molecular bromine
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Primary and secondary alcohols were smoothly oxidized to the corresponding aldehydes and ketones in high yields at room temperature with 1.1 equiv. of molecular bromine by using a catalytic amount of N-t-butyl-2-nitrobenzenesulfenamide in the coexistence of potassium carbonate and molecular sieves 4A.
- Matsuo, Jun-Ichi,Kawana, Asahi,Yamanaka, Hiroyuki,Mukaiyama, Teruaki
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p. 182 - 183
(2007/10/03)
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- N-tert-Butylbenzenesulfenamide-catalyzed oxidation of alcohols to the corresponding carbonyl compounds with N-chlorosuccinimide
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N-tert-Butylbenzenesulfenamide (1)-catalyzed oxidation of various primary and secondary alcohols to the corresponding aldehydes and ketones was efficiently carried out by using N-chlorosuccinimide (NCS) in the coexistence of potassium carbonate and molecular sieves 4? at easy-to-control temperatures ranging from 0°C to room temperature. The present catalytic oxidation was performed without giving any damage to the functional groups in alcohols, and was particularly effective in the oxidation of alcohols that formed labile aldehydes because of its mild reaction conditions. Further, selective oxidation of primary hydroxy groups took place in 1-catalyzed oxidation of several diols. Mechanistic investigation suggested that the chlorination of the sulfenamide 1 by NCS led to the formation of a key species, N-tert-butylbenzenesulfinimidoyl chloride (2), which in turn oxidized alcohols in the presence of potassium carbonate to afford carbonyl products by accompanying regeneration of the catalyst 1.
- Matsuo, Jun-Ichi,Iida, Daisuke,Yamanaka, Hiroyuki,Mukaiyama, Teruaki
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p. 6739 - 6750
(2007/10/03)
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- The Dual Roles of Oxodiperoxovanadate Both as a Nucleophile and an Oxidant in the Green Oxidation of Benzyl Alcohols or Benzyl Halides to Aldehydes and Ketones
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One catalyst, two roles: VO(O2)2- reacts as a nucleophilic oxidant under acidic conditions towards benzyl alcohols. Altogether 15 alcohols have been oxidized, in the absence of organic solvent, in excellent yields. Benzyl halides are also oxidized by H2O 2 in water catalyzed by oxodiperoxovanadate and a phase transfer catalyst into aromatic aldehydes and ketones (see scheme). This reaction is the first green oxidation of benzyl halides.
- Li, Chunbao,Zheng, Pengwu,Li, Jie,Zhang, Hang,Cui, Yi,Shao, Qiyun,Ji, Xiujie,Zhang, Jian,Zhao, Pengying,Xu, Yanli
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p. 5063 - 5066
(2007/10/03)
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- Oxidation of alcohols using cerium(IV) alkyl phosphonate modified silica
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The oxidation of a range of alcohols to ketones or carboxylic acids proceeds in good yield using catalytic quantities of cerium(IV) phosphonate modified silica and sodium bromate as the re-oxidant.
- Al-Haq, Nazli,Sullivan, Alice C.,Wilson, John R. H.
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p. 769 - 771
(2007/10/03)
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- Highly sustainable catalytic dehydrogenation of alcohols with evolution of hydrogen gas
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The catalytic dehydrogenation of alcohols into aldehydes and ketones in the absence of H-acceptors was studied with several transition metal catalysts in order to develop a large-scale procedure. Applying Ru(OCOCF3)2(CO)(PPh3)2, the so called Robinson catalyst, several secondary alcohols could be dehydrogenated with high selectivity into the corresponding ketones in relatively short reaction times. Highly effective atom utilization could be realized avoiding solvents and giving hydrogen gas as the sole by-product. However, in contrast to Robinson's work the catalytic dehydrogenation of primary alcohols appeared to be problematic due to decarbonylation with concomitant catalyst deactivation and aldol condensation under the strong acid or basic conditions applied.
- Ligthart,Meijer,Donners,Meuldijk,Vekemans,Hulshof
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p. 1507 - 1509
(2007/10/03)
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- Wet silica-supported permanganate for the cleavage of semicarbazones and phenylhydrazones under solvent-free conditions
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Wet silica-supported potassium permanganate was used as an inexpensive and efficient reagent for conversion of semicarbazones and phenylhydrazones to the corresponding carbonyl compounds under solid-state conditions.
- Hajipour, Abdol R.,Adibi, Hadi,Ruoho, Arnold E.
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p. 4553 - 4555
(2007/10/03)
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- Stereoselective synthesis of (6R)- and (6S)-diosphenol and Ψ-diosphenol
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Methods are discussed for the stereoselective synthesis of the (R)-and (S)-enantiomers of the diosphenols (5)-(8) by utilizing the commercially available stereoisomers (9), (12), (23) and (25) of carvone and limonene, respectively, as chiral starting materials.
- Schneider, David F,Viljoen, Murray S
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p. 5307 - 5315
(2007/10/03)
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- A new method for oxidation of various alcohols to the corresponding carbonyl compounds by using n-t-butylbenzenesulfinimidoyl chloride
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Various primary and secondary alcohols were smoothly oxidized to the corresponding aldehydes and ketones by using a new oxidizing agent, N-t-butylbenzenesulfinimidoyl chloride (4a), in the coexistence of DBU or zinc oxide. The present oxidation proceeded under mild conditions via five-membered intramolecular proton-transfer of an alkyl arenesulfinimidate intermediate.
- Matsuo, Jun-Ichi,Iida, Daisuke,Tatani, Kazuya,Mukaiyama, Teruaki
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p. 223 - 234
(2007/10/03)
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- Catalytic oxidation of alcohols with allyl diethyl phosphate and palladium acetate
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Allyl diethyl phosphate (ADP) was found to function as a stoichiometric hydrogen acceptor in a catalytic oxidation reaction of alcohols with Pd(OAc)2. A variety of acyclic primary and secondary alcohols were oxidized in good yields and under mild conditions to the corresponding aldehydes and ketones, in the presence of Na2CO3 or K2CO3. Simple aliphatic primary alcohols yielded esters, exclusively. Polar ligand solvents (DMF, DMSO) were found to accelerate the reaction. Slow, but high yield reactions were encountered in THF and acetonitrile as solvents. The reactivity of several other allyl systems serving as H-acceptors, and several Pd compounds serving as catalysts, in the above oxidation reaction, was evaluated. It has been experimentally demonstrated (H-NMR) that ADP is capable of generating a π-allyl-Pd complex using a Pd(0) complex. Consequently, a catalytic cycle was proposed for the above oxidation reaction.
- Shvo, Youval,Goldman-Lev, Vered
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p. 151 - 156
(2007/10/03)
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- Silica gel supported jones reagent (SJR): A simple, versatile, and efficient reagent for oxidation of alcohols in non-aqueous media
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Oxidation of alcohols to carbonyl compounds has been carried out by utilization of Jones reagent supported on silica gel (SJR). The SJR procedure has advantages over traditional Jones oxidation procedure. This procedure is safer to carry out and simplified workup by allowing organic media.
- Ali,Wiggin
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p. 3383 - 3393
(2007/10/03)
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- Polymer-supported N-methylmorpholine N-oxide as an efficient and readily recyclable co-oxidant in the TPAP oxidation of alcohols
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A readily available, polymer supported amine N-oxide has been prepared and shown to be a practicable, efficient, selective, and readily recyclable co-oxidant in the TPAP oxidation of alcohols.
- Brown,Kerr,Lindsay,Pike,Ratcliffe
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p. 1257 - 1259
(2007/10/03)
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- Bis(sym-collidine)bromine(I) hexafluorophosphate as oxidant
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Primary and secondary alcohols in solution in methylene chloride are oxidised with bis(sym-collidine)bromine(I) hexafluorophosphate in good yields to the carbonyl compounds. For secondary and tertiary alcohols in which one of the substituents is a 4-methoxyphenyl group the oxidation takes place by cleavage of the phenyl-sp3 carbon bond and formation of bromoanisole and carbonyl compounds. (C) 2000 Elsevier Science Ltd.
- Rousseau,Robin
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p. 8881 - 8885
(2007/10/03)
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- Facile and clean oxidation of alcohols in water using hypervalent iodine(III) reagents
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An environmentally benign oxidation of alcohols in water using iodosobenzene (PhI=O) or a polymer-supported (diacetoxyiodo)benzene (PSDIB) with KBr has been achieved (see scheme). This method results in the catalytic activation of a variety of sluggishly reactive and/or sparsely soluble hypervalent iodine reagents in water under neutral conditions.
- Tohma, Hirofumi,Takizawa, Shinobu,Maegawa, Tomohiro,Kita, Yasuyuki
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p. 1306 - 1308
(2007/10/03)
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- Chemoselective C-H oxidation of alcohols to carbonyl compounds with iodosobenzene catalyzed by (Salen)chromium complex
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Primary and secondary alcohols with benzylically and allylically activated C-H bonds are chemoselectively oxidized to the corresponding carbonyl compounds by the (salen)Cr(III) complex I as the catalyst and iodosobenzene as the oxygen source; the oxidizing species is the Cr(V) oxo complex. Allylic alcohols with fully substituted double bonds give appreciable amounts of epoxides besides the C-H oxidation products enones, while saturated alcohols are less readily oxidized.
- Adam, Waldemar,Gelalcha, Feyissa Gadissa,Saha-Moeller, Chantu R.,Stegmann, Veit R.
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p. 1915 - 1918
(2007/10/03)
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