- 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
-
supporting information
p. 6525 - 6529
(2021/09/02)
-
- 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
-
supporting information
(2021/06/03)
-
- A TEMPO-Functionalized Ordered Mesoporous Polymer as a Highly Active and Reusable Organocatalyst
-
The properties of high stability, periodic porosity, and tunable nature of ordered mesoporous polymers make these materials ideal catalytic nanoreactors. However, their application in organocatalysis has been rarely explored. We report herein for the first time the incorporation of a versatile organocatalyst, 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), into the pores of an FDU-type mesoporous polymer via a pore surface engineering strategy. The resulting FDU-15-TEMPO possesses a highly ordered mesoporous organic framework and enhanced stability, and shows excellent catalytic activity in the selective oxidation of alcohols and aerobic oxidative synthesis of 2-substituted benzoxazoles, benzimidazoles and benzothiazoles. Moreover, the catalyst can be easily recovered and reused for up to 7 consecutive cycles.
- Guo, Ying,Wang, Wei David,Li, Shengyu,Zhu, Yin,Wang, Xiaoyu,Liu, Xiao,Zhang, Yuan
-
supporting information
p. 3689 - 3694
(2021/09/29)
-
- Synthesis of enantiopure triols from racemic Baylis?Hillman adducts using a diastereoselective peroxidation reaction
-
Using a chiral (?)-menthone auxiliary, enantiopure cyclic derivatives of Baylis?Hillman adducts were synthesized. A diastereoselective peroxidation reaction was used to introduce an oxygen atom and establish another stereocenter. The resulting products could be elaborated by employing a one-flask reduction?acetylation protocol followed by a diastereoselective nucleophilic substitution reaction. Removal of the (?)-menthone auxiliary provided an enantiopure triol with a structure related to naturally occurring polyols.
- Woerpel,Zuckerman, Dylan S.
-
supporting information
p. 9075 - 9080
(2020/12/02)
-
- Photochemical Transformations with Iodine Azide after Release from an Ion-Exchange Resin
-
This report discloses the photochemical homolytic cleavage of iodine azide after its formation following release from polymer-bound bisazido iodate(I) anions. A series of radical reactions are reported including the 1,2-functionlization of alkenes and the unprecedented chemoselective oxidation of secondary alcohols in the presence of primary alcohols.
- Dr?ger, Gerald,K?sel, Teresa,Kirschning, Andreas,Schulz, G?ran
-
supporting information
p. 12376 - 12380
(2020/05/08)
-
- IBX-TfOH mediated oxidation of alcohols to aldehydes and ketones under mild reaction conditions
-
An efficient, practical and facile procedure has been developed for the oxidation of primary and secondary alcohols using IBX-TfOH catalytic system in 1,4-dioxane at ambient temperature. The reaction affords quantitative yields of the corresponding carbonyl compounds without the formation of over oxidized products. The present synthetic protocol is compatible with a variety of substrates having arene, heteroarene and alkene functionalities. The developed synthetic protocol can be used for higher scale reactions as evident by the oxidation of alcohol at 1 g scale in higher yields by a simple filtration process.
- Kumar, Kamlesh,Kumar, Prashant,Joshi, Penny,Rawat, Diwan S
-
supporting information
(2020/03/04)
-
- Rediscovering aminal chemistry: Copper(ii) catalysed formation under mild conditions
-
Aminals, the N,N analogues of acetals, have been thoroughly explored in organic chemistry, with a particular focus on heteroaromatic aldehyde lithiation. Nevertheless, the existing methodologies for their formation typically employ harsh conditions limiting their usefulness. In this work, we present an efficient and mild methodology for the preparation of aminals from aromatic aldehydes, including furanic platforms. These mild conditions allowed ease of access to a plethora of aminals and as such we set out to explore previously unaccessible potential applications. By studying the stability of various aminals, we were able to develop a simple aldehyde protecting group based on a commercial diamine which is deprotected under mind conditions. We developed a protocol for the scavenging of genotoxic aldehydes by taking advantage of our methodology and a diamine resin, as well as early studies on the development of a stimuli-responsive release system using a salycil aldehyde derived aminal. This journal is
- Afonso, Carlos A. M.,António, Jo?o P. M.,Gomes, Rafael F. A.,Mendon?a, Ricardo,Pereira, Juliana G.
-
supporting information
p. 7484 - 7490
(2020/11/18)
-
- Menthylamine synthesis via gold-catalyzed hydrogenation of menthone oxime
-
In the current work gold nanoparticles supported on oxides (MgO, Al2O3, ZrO2, TiO2) were used for menthylamine synthesis via menthone oxime hydrogenation. An increase of the gold nanoparticles size and application of metal oxides with a strong basic character such as magnesia favored deoximation to menthone. Au/Al2O3 catalyst with the gold nanoparticles size of 2.0 nm afforded high catalytic activity and selectivity to menthylamine. The reaction kinetics including stereoselectivity to the reaction products and recyclability of the catalyst was studied using Au/Al2O3 in the temperature range 90?110 °C under hydrogen pressure of 5.5–7.5 bar. The catalytic behavior was influenced by the solvent nature, with higher selectivity to desired amine achieved using methanol. The reaction rate was pressure independent, while has first order with respect to menthone oxime concentration. Stereoselectivity to menthylamines and menthones was independent on the reaction temperature and the hydrogen pressure.
- Demidova, Yu. S.,Mozhaitsev, E. S.,Murzin, D. Yu.,Nefedov, A. A.,Salakhutdinov, N. F.,Saraev, A. A.,Simakov, A.,Simakova, I. L.,Suslov, E. V.,Volcho, K. P.
-
-
- 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 0094; 0095
(2020/04/02)
-
- Design and synthesis of a versatile cooperative catalytic aerobic oxidation system with co-immobilization of palladium nanoparticles and laccase into the cavities of MCF
-
We have designed a versatile reusable cooperative catalyst oxidation system, consisting of palladium nanoparticles and laccase with unprecedented reactivity. This biohybrid catalyst was synthesized by the stepwise immobilization of laccase as an enzyme and Pd as a nanometallic component into the same cavity of siliceous mesocellular foams (MCF). MCF and nanobiohybrid catalyst were characterized by BET, SAXS, SEM, EDX elemental mapping, ICP-OES, TEM, TGA, FT-IR, and XPS techniques and the stepwise immobilization of laccase enzyme and Pd onto MCF was evaluated through several compelling electrochemical studies. The present catalytic system exhibits high activity toward (i) aerobic oxidation of alcohols to the corresponding carbonyl compounds, (ii) aerobic oxidation of cyclohexanol and cyclohexanone to phenol and (iii) aerobic dehydrogenation of important N-heteocyclic compounds (tetrahydro quinazolines, quinazolonones, pyrazolines and 1,4-diydropyridines) in the presence of catalytic amount of hydroquinone (HQ) as mediator in phosphate buffer (0.1 M, pH 4.5, 4 mL)/THF (4%, 1 mL) as solvent under mild conditions. The immobilization of both oxygen-activating catalyst (laccase) and oxidizing catalyst (Pd) onto the same support makes the present catalyst system superior to other currently available heterogeneous palladium based catalytic aerobic oxidation systems.
- Moradi, Sirvan,Shokri, Zahra,Ghorashi, Nadya,Navaee, Aso,Rostami, Amin
-
p. 305 - 319
(2020/01/21)
-
- Photochemical oxidation of benzylic primary and secondary alcohols utilizing air as the oxidant
-
A mild and green photochemical protocol for the oxidation of alcohols to aldehydes and ketones was developed. Utilizing thioxanthenone as the photocatalyst, molecular oxygen from air as the oxidant and cheap household lamps or sunlight as the light source, a variety of primary and secondary alcohols were converted into the corresponding aldehydes or ketones in low to excellent yields. The reaction mechanism was extensively studied.
- Nikitas, Nikolaos F.,Tzaras, Dimitrios Ioannis,Triandafillidi, Ierasia,Kokotos, Christoforos G.
-
supporting information
p. 471 - 477
(2020/02/13)
-
- 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
-
p. 1313 - 1319
(2019/01/25)
-
- A process for preparing optically pure L - menthones method and used for the method of the catalyst
-
The present invention provides a process for preparing optically pure L - menthones method and used for the method of the catalyst. Under the action of the oxidation catalyst, L - menthol to the menthol in the selective oxidation, preparation of the optically pure L - menthones. The oxidation catalyst comprises a chiral salen manganese compound and hydrogen peroxide. The stereoselectivity L - menthones of synthesis, the optical purity of the product can be as high as 99 ee %.
- -
-
Paragraph 0057; 0058; 0061-0064
(2019/05/15)
-
- Cucurbit[5]uril-mediated electrochemical hydrogenation of α,β-unsaturated ketones
-
The potential of cucurbit[5]uril to be used as inverse phase transfer catalyst in electrocatalytic hydrogenation of α,β-unsaturated ketones is illustrated. The interaction behavior among isophorone and cucurbit[5]uril was also investigated using cyclic voltammetry and UV/vis absorption spectroscopy. The results concerning to both techniques revealed an enhancement in the intensity of the absorption peak and also in the current cathodic peak of isophorone in presence of cucurbit[5]uril. This achievement is related to the increase of the isophorone solubility in the medium being an indicative of a host-guest complex formation. The electrochemical hydrogenation of isophorone using cucurbit[5]uril was more efficient than others well-stablish methodologies. Regarding to (R)-(+)-pulegone and (S)-(+)-carvone, the use of cucurbit[5]uril leads to an increase of 17% and 9%, on average, respectively, in the yields when compared to the control reaction. The efficiency of selective C=O bond hydrogenation of 1-acetyl-1-cyclohexene was evaluated. The presence of cucurbit[5]uril increased by 12% the hydrogenations yields of 1-acetyl-1-cyclohexene when compared to the control reaction. In this sense, these results open up an opportunity to carry out electrocatalytic reactions within the cucurbit[5]uril environment.
- Sales, Ayrlane,de Oliveira e Castro, Isabela Andrade,de Menezes, Frederico Duarte,Selva, Thiago Matheus Guimar?es,Vilar, Márcio
-
p. 295 - 305
(2019/09/03)
-
- Menthane-Based Chloride-Bridged η3-Bis-π-Allylpalladium Chloride Dimers: Catalytic Asymmetric Allylation of Imines
-
Menthane-based η3-bis-π-allylpalladium chloride dimer complexes have been prepared for the first time. They exist as dimeric η3-bis-π-allylpalladium with four chloride bridges. The complexes catalyze the asymmetric allylation of vari
- Jha, Amit K.,Fernandes, Rodney A.
-
p. 2857 - 2863
(2019/05/15)
-
- Chemoselective Oxidation of Equatorial Alcohols with N-Ligated λ3-Iodanes
-
The site-selective and chemoselective functionalization of alcohols in complex polyols remains a formidable synthetic challenge. Whereas significant advancements have been made in selective derivatization at the oxygen center, chemoselective oxidation to the corresponding carbonyls is less developed. In cyclic systems, whereas the selective oxidation of axial alcohols is well known, a complementary equatorial selective process has not yet been reported. Herein we report the utility of nitrogen-ligated (bis)cationic λ3-iodanes (N-HVIs) for alcohol oxidation and their unprecedented levels of selectivity for the oxidation of equatorial over axial alcohols. The conditions are mild, and the simple pyridine-ligated reagent (Py-HVI) is readily synthesized from commercial PhI(OAc)2 and can be either isolated or generated in situ. Conformational selectivity is demonstrated in both flexible 1,2-substituted cyclohexanols and rigid polyol scaffolds, providing chemists with a novel tool for chemoselective oxidation.
- Mikhael, Myriam,Adler, Sophia A.,Wengryniuk, Sarah E.
-
supporting information
p. 5889 - 5893
(2019/08/26)
-
- Oxidation of secondary alcohols using solid-supported hypervalent iodine catalysts
-
It is shown how secondary alcohols are oxidized to provide the corresponding ketones by use of Oxone and solid-supported hypervalent iodine catalysts. Under experimentally simple conditions with acetonitrile at elevated temperatures, excellent conversions were achieved with low catalyst loadings (0.2-5 mol%) when employing the conjugates 5 and 6 derived from IBX and IBS. The catalysts are broadly applicable to a range of alcohol substrates. Of primary importance with respect to sustainability issues, the metal-free catalysts are easily removed from the reaction mixture through filtration, and they can be re-used in oxidation processes for multiple times, without loss of catalytic activity.
- Ballaschk, Frederic,Kirsch, Stefan F.
-
supporting information
p. 5896 - 5903
(2019/11/11)
-
- Heterogeneously Catalysed Oxidative Dehydrogenation of Menthol in a Fixed-Bed Reactor in the Gas Phase
-
For the first time, the oxidative dehydrogenation of (?)-menthol to (?)-menthone and (+)-isomenthone in a marketable quality was carried out in a continuous gas phase reactor as a sustainable process using molecular oxygen as green oxidant and solid catalysts which do not contaminate the product mixture and which are easily to remove. The diastereomeric purity remained largely unchanged. Three types of catalysts were found to be very active and selective in the formation of menthone and isomenthone: AgSr/SiO2, CuO distributed on a basic support and RuMnCe/CeO2, where Ru, Mn and Ce exist in an oxidized state. The best overall yield of menthon/isomenthone obtained with an Ag-based catalyst was 58 % at 64 % selectivity, with a Cu-based catalyst 41 % at 51 % selectivity and with a Ru-based catalyst 68 % at 73 % selectivity. Reaction conditions were widely optimized.
- Kulik, Anna,Neubauer, Katja,Eckelt, Reinhard,Bartling, Stephan,Panten, Johannes,K?ckritz, Angela
-
p. 1066 - 1075
(2019/06/24)
-
- Method for preparing L-menthone
-
The invention provides a method for preparing L-menthone. The method starts from isopulegol containing L-isopulegol, and prepares L-menthone through a method for selectively catalyzing the L-isopulegol to generate hydrogen transfer. The method has advantages of being simple in operation, low in catalyst cost, high in product yield and less in three wastes (waste gas, waste water and industrial residue); through a technology of hydrogenation transfer, the using of hydrogen is not needed, so that the method has better technology safety, and is suitable for industrial production application. TheL-menthone can be performed by performing selective hydrogen transfer on the L-isopulegol in the isopulegol under the action of a transition metal catalyst through the provided method; and the transition metal catalyst includes a transition metal compound and a chiral phosphine ligand.
- -
-
Paragraph 0058; 0059; 0064-0066; 0069-0083
(2019/05/08)
-
- Method for producing Isopulegol from menthone
-
Preparing menthone from isopulegol, comprises carrying out dehydrogenation- or hydrogenation reaction in liquid phase using a homogeneously dissolved catalyst comprising at least one metal atom of the group 8, 9 or 10. An independent claim is also included for the reaction product obtainable by the above method.
- -
-
Paragraph 0070; 0071; 0072; 0073; 0074; 0075; 0076-0078
(2019/05/16)
-
- Method for preparing high-purity L-menthone
-
The invention discloses a method for preparing high-purity L-menthone. The method includes: under action of a solid base loaded ruthenium catalyst, subjecting raw material L-isopulegol for heterogeneous catalytic reaction to obtain a product-high-purity L-menthone. In mild reaction conditions, the ruthenium catalyst loaded on solid base is utilized to heterogeneously catalyze L-isopulegol to prepare L-menthone with high yield, the catalyst can be recycled conveniently and quickly, and the method is simpler in reaction process, low in reaction cost and high in environment friendliness; througha hydrogenation transfer process, hydrogen is not needed, so that the method has better process safety and industrial prospect.
- -
-
Paragraph 0071-0074; 0075-0078; 0079-0082; 0083-0096
(2019/04/06)
-
- A method for the preparation of aldehydes
-
The invention discloses a method for the preparation of ketone, relates to the field of organic synthesis. This invention adopts the organic solvent as a medium, cyclopropene [...] derivative as an active agent, activated DMSO oxidation [...] oxidation. The method of the invention is simple, easy to operate, rapid reaction rate, mild reaction, the reaction rate can be adjusted, more economic, to achieve industrial laid the foundation.
- -
-
Paragraph 0132; 0133
(2019/05/28)
-
- Revisiting Sodium Hypochlorite Pentahydrate (NaOCl·5H 2 O) for the Oxidation of Alcohols in Acetonitrile without Nitroxyl Radicals
-
Sodium hypochlorite pentahydrate (NaOCl·5H 2 O) is capable of oxidizing alcohols in acetonitrile at 20 °C without the use of catalysts. The oxidation is selective to allylic, benzylic, and secondary alcohols. Aliphatic primary alcohols are not oxidized.
- Hirashita, Tsunehisa,Sugihara, Yuto,Ishikawa, Shota,Naito, Yohei,Matsukawa, Yuta,Araki, Shuki
-
p. 2404 - 2407
(2018/11/23)
-
- Arylruthenium(III) Porphyrin-Catalyzed C-H Oxidation and Epoxidation at Room Temperature and [RuV(Por)(O)(Ph)] Intermediate by Spectroscopic Analysis and Density Functional Theory Calculations
-
The development of highly active and selective metal catalysts for efficient oxidation of hydrocarbons and identification of the reactive intermediates in the oxidation catalysis are long-standing challenges. In the rapid hydrocarbon oxidation catalyzed by ruthenium(IV) and -(III) porphyrins, the putative Ru(V)-oxo intermediates remain elusive. Herein we report that arylruthenium(III) porphyrins are highly active catalysts for hydrocarbon oxidation. Using catalyst [RuIII(TDCPP)(Ph)(OEt2)] (H2TDCPP = 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin), the oxidation of C-H bonds of various hydrocarbons with oxidant m-CPBA at room temperature gave alcohols/ketones in up to 99% yield within 1 h; use of [nBu4N]IO4 as a mild alternative oxidant avoided formation of lactone from cyclic ketone in C-H oxidation, and the catalytic epoxidation with up to 99% yield and high selectivity (no aldehydes as side product) was accomplished within 5 min. UV-vis, electrospray ionization-mass spectrometry, resonance Raman, electron paramagnetic resonance, and kinetic measurements and density functional theory calculations lend evidence for the formation of Ru(V)-oxo intermediate [RuV(TDCPP)(O)(Ph)].
- Shing, Ka-Pan,Cao, Bei,Liu, Yungen,Lee, Hung Kay,Li, Ming-De,Phillips, David Lee,Chang, Xiao-Yong,Che, Chi-Ming
-
supporting information
p. 7032 - 7042
(2018/06/12)
-
- Chemoenzymatic Synthesis of the Intermediates in the Peppermint Monoterpenoid Biosynthetic Pathway
-
A chemoenzymatic approach providing access to all four intermediates in the peppermint biosynthetic pathway between limonene and menthone/isomenthone, including noncommercially available intermediates (-)-trans-isopiperitenol (2), (-)-isopiperitenone (3), and (+)-cis-isopulegone (4), is described. Oxidation of (+)-isopulegol (13) followed by enolate selenation and oxidative elimination steps provides (-)-isopiperitenone (3). A chemical reduction and separation route from (3) provides both native (-)-trans-isopiperitenol (2) and isomer (-)-cis-isopiperitenol (18), while enzymatic conjugate reduction of (-)-isopiperitenone (3) with IPR [(-)-isopiperitenone reductase)] provides (+)-cis-isopulegone (4). This undergoes facile base-mediated chemical epimerization to (+)-pulegone (5), which is subsequently shown to be a substrate for NtDBR (Nicotiana tabacum double-bond reductase) to afford (-)-menthone (7) and (+)-isomenthone (8).
- Cheallaigh, Aisling Ní,Mansell, David J.,Toogood, Helen S.,Tait, Shirley,Lygidakis, Antonios,Scrutton, Nigel S.,Gardiner, John M.
-
p. 1546 - 1552
(2018/08/04)
-
- Engineering the "missing Link" in Biosynthetic (-)-Menthol Production: Bacterial Isopulegone Isomerase
-
The realization of a synthetic biology approach to microbial (1R,2S,5R)-(-)-menthol (1) production relies on the identification of a gene encoding an isopulegone isomerase (IPGI), the only enzyme in the Mentha piperita biosynthetic pathway as yet unidentified. We demonstrate that Δ5-3-ketosteroid isomerase (KSI) from Pseudomonas putida can act as an IPGI, producing (R)-(+)-pulegone ((R)-2) from (+)-cis-isopulegone (3). Using a robotics-driven semirational design strategy, we identified a key KSI variant encoding four active site mutations, which confer a 4.3-fold increase in activity over the wild-type enzyme. This was assisted by the generation of crystal structures of four KSI variants, combined with molecular modeling of 3 binding to identify key active site residue targets. The KSI variant was demonstrated to function efficiently within cascade biocatalytic reactions with downstream Mentha enzymes pulegone reductase and (-)-menthone:(-)-menthol reductase to generate 1 from 3. This study introduces the use of a recombinant IPGI, engineered to function efficiently within a biosynthetic pathway for the production of 1 in microorganisms.
- Currin, Andrew,Dunstan, Mark S.,Johannissen, Linus O.,Hollywood, Katherine A.,Vinaixa, Maria,Jervis, Adrian J.,Swainston, Neil,Rattray, Nicholas J. W.,Gardiner, John M.,Kell, Douglas B.,Takano, Eriko,Toogood, Helen S.,Scrutton, Nigel S.
-
p. 2012 - 2020
(2018/03/13)
-
- ATP3 and MTP3: Easily Prepared Stable Perruthenate Salts for Oxidation Applications in Synthesis
-
The Ley–Griffith tetra-n-propylammonium perruthenate (TPAP) catalyst has been widely deployed by the synthesis community, mainly for the oxidation of alcohols to aldehydes and ketones, but also for a variety of other synthetic transformations (e.g. diol cleavage, isomerizations, imine formation and heterocyclic synthesis). Such popularity has been forged on broad reaction scope, functional group tolerance, mild conditions, and commercial catalyst supply. However, the mild instability of TPAP creates preparation, storage, and reaction reproducibility issues, due to unpreventable slow decomposition. In search of attributes conducive to catalyst longevity an extensive range of novel perruthenate salts were prepared. Subsequent evaluation unearthed a set of readily synthesized, bench stable, phosphonium perruthenates (ATP3 and MTP3) that mirror the reactivity of TPAP, but avoid storage decomposition issues.
- Moore, Peter W.,Read, Christopher D. G.,Bernhardt, Paul V.,Williams, Craig M.
-
supporting information
p. 4556 - 4561
(2018/03/13)
-
- Nitrosotetrazolium-Catalyzed Aerobic Oxidation of Alcohols to the Corresponding Carbonyl Compounds
-
A mesoionic-nitrosotetrazolium-catalyzed aerobic oxidation of alcohols is reported. In the presence of catalytic amounts of 5-nitroso-1,3-diphenyltetrazolium tetrafluoroborate (5 mol-%) and nitric acid (20 mol-%), a wide range of alcohols are oxidized to the corresponding aldehydes and ketones in yields of 53–100 % at room temperature under ambient air or oxygen conditions. This oxidation shows a strong preference for secondary alcohols over primary alcohols; sterically hindered alcohols are also smoothly oxidized. A mechanism involving a nitroso/NOx catalytic cycle is proposed.
- Matsukawa, Yuta,Hirashita, Tsunehisa,Araki, Shuki
-
p. 1359 - 1363
(2018/04/02)
-
- Ruthenium-phenol catalysts and method of preparing menthone from isopulegol
-
The present invention is directed towards a catalyst which is obtainable by contacting in situ a ruthenium precursor and a phenol derivative. Furthermore, the present invention is directed towards the use of said catalyst in transfer hydrogenation reactions. In particular, the present invention is directed to a method for preparing menthone starting from isopulegol.
- -
-
Page/Page column 25
(2017/11/09)
-
- New biobased tetrabutylphosphonium ionic liquids: Synthesis, characterization and use as a solvent or co-solvent for mild and greener Pd-catalyzed hydrogenation processes
-
Phosphonium-based Ionic Liquids (PhosILs) with natural organic derived anions (l-lactate, l-tartrate, malonate, succinate, l-malate, pyruvate, d-glucuronate, d-galacturonate, ferulate, p-coumarate) were easily prepared by acid-base method from tetrabutylphosphonium hydroxide and an excess of the corresponding acid with good yields. Their characterization was realized through classical NMR, IR and elemental analysis techniques; their viscosity and ATG parameters were also determined. These ionic liquids showed good performance and recyclability in the selective Pd-catalyzed hydrogenation of alkenes, polyenes like linoleic acid and enantioselective hydrogenation of unsaturated ketones such as isophorone at room temperature under atmospheric H2 pressure. Furthermore, NMR studies leading to computational calculations were performed to establish easily the composition of the resulting mixture obtained through the hydrogenation of linoleic acid.
- Hayouni, Safa,Robert, Anthony,Ferlin, Nadège,Amri, Hassen,Bouquillon, Sandrine
-
p. 113583 - 113595
(2016/12/16)
-
- An alkoxyamine compound, alkoxy alcohol oxidation catalyst and method of using the alcohol oxidation
-
PROBLEM TO BE SOLVED: To provide a novel alkoxyamine compound which can be easily manufactured and applied suitably as an alcohol oxidation catalyst capable of exerting sufficiently high catalytic activity in oxidation of primary and secondary alcohols.SOLUTION: There is provided an alkoxyamine compound with a homoadamantane skeleton represented by the general formula (1) in the figure. [In the formula (1), Rand Rare each independently any one selected from the group consisting of a hydrogen atom and alkyl groups that may be substituted.
- -
-
Paragraph 0096; 0098-0100
(2017/02/02)
-
- Sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals; An effective re-oxidant for TEMPO oxidation
-
The novel oxidant of sodium hypochlorite pentahydrate (NaOCl·5H2O), which is now available for industrial and laboratory use has several advantageous properties. The crystalline material has 44% of NaOCl, contains minimal sodium hydroxide and sodium chloride, and the aqueous solution indicates pH 11-12. Herein, NaOCl·5H2O crystals are examined for use as an oxidant for primary and secondary alcohols, with or without nitroxyl radicals, in the presence or absence of phase-transfer catalysts. The pentahydrate crystals alone (without nitroxyl radicals) demonstrate a powerful oxidizing ability, converting secondary alcohols to the corresponding ketones. In the presence of TEMPO (2,2,6,6-tetramethylpiperidine 1-oxyl) or 1-Me-AZADO (1-methyl-2-azaadamantane N-oxy radical), sterically hindered secondary alcohols are oxidized without pH adjustment. A proposed mechanism for the oxidation is discussed.
- Okada, Tomohide,Asawa, Tomotake,Sugiyama, Yukihiro,Iwai, Toshiaki,Kirihara, Masayuki,Kimura, Yoshikazu
-
p. 2818 - 2827
(2016/05/19)
-
- 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)
-
- Highly efficient aerobic oxidation of alcohols by using less-hindered nitroxyl-radical/copper catalysis: Optimum catalyst combinations and their substrate scope
-
The oxidation of alcohols into their corresponding carbonyl compounds is one of the most fundamental transformations in organic chemistry. In our recent report, 2-azaadamantane N-oxyl (AZADO)/copper catalysis promoted the highly chemoselective aerobic oxidation of unprotected amino alcohols into amino carbonyl compounds. Herein, we investigated the extension of the promising AZADO/copper-catalyzed aerobic oxidation of alcohols to other types of alcohol. During close optimization of the reaction conditions by using various alcohols, we found that the optimum combination of nitroxyl radical, copper salt, and solution concentration was dependent on the type of substrate. Various alcohols, including highly hindered and heteroatom-rich ones, were efficiently oxidized into their corresponding carbonyl compounds under mild conditions with lower amounts of the catalysts.
- Sasano, Yusuke,Kogure, Naoki,Nishiyama, Tomohiro,Nagasawa, Shota,Iwabuchi, Yoshiharu
-
supporting information
p. 1004 - 1009
(2015/03/31)
-
- METHOD FOR OXIDIZING ALCOHOLS
-
Oxidation of alcohols to carbonyl compounds is one of important basic reactions in organic synthesis. The present invention provides an oxidation method of alcohols, which secures high productivity and safely and conveniently obtains a targeted substance with good selectivity at high yields. The oxidation method of alcohols oxidizes alcohols represented by general formula 1, thereby manufacturing carbonyl compounds derived from the alcohols, and uses sodium hypochlorite pentahydrate as an oxidizing agent in the presence or absence of a catalyst. (In general formula 1, R^1 represents an alkyl group, an aryl group or an aralkyl group, and R^2 represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom.)COPYRIGHT KIPO 2015
- -
-
Paragraph 0031-0033
(2016/12/01)
-
- Substrate flexibility and reaction specificity of tropinone reductase-like short-chain dehydrogenases
-
Annotations of protein or gene sequences from large scale sequencing projects are based on protein size, characteristic binding motifs, and conserved catalytic amino acids, but biochemical functions are often uncertain. In the large family of short-chain dehydrogenases/reductases (SDRs), functional predictions often fail. Putative tropinone reductases, named tropinone reductase-like (TRL), are SDRs annotated in many genomes of organisms that do not contain tropane alkaloids. SDRs in vitro often accept several substrates complicating functional assignments. Cochlearia officinalis, a Brassicaceae, contains tropane alkaloids, in contrast to the closely related Arabidopsis thaliana. TRLs from Arabidopsis and the tropinone reductase isolated from Cochlearia (CoTR) were investigated for their catalytic capacity. In contrast to CoTR, none of the Arabidopsis TRLs reduced tropinone in vitro. NAD(H) and NADP(H) preferences were relaxed in two TRLs, and protein homology models revealed flexibility of amino acid residues in the active site allowing binding of both cofactors. TRLs reduced various carbonyl compounds, among them terpene ketones. The reduction was stereospecific for most of TRLs investigated, and the corresponding terpene alcohol oxidation was stereoselective. Carbonyl compounds that were identified to serve as substrates were applied for modeling pharmacophores of each TRL. A database of commercially available compounds was screened using the pharmacophores. Compounds identified as potential substrates were confirmed by turnover in vitro. Thus pharmacophores may contribute to better predictability of biochemical functions of SDR enzymes.
- Reinhardt, Nicole,Fischer, Juliane,Coppi, Ralph,Blum, Elke,Brandt, Wolfgang,Draeger, Birgit
-
-
- METHOD FOR PREPARING MENTHONE FROM ISOPULEGOL
-
The present invention relates to a method for preparing menthone, starting from isopulegol, using specific homogeneous catalysts.
- -
-
Paragraph 0096
(2014/03/25)
-
- Anaerobic nitroxide-catalyzed oxidation of alcohols using the NO +/NO· redox pair
-
A new method for alcohol oxidation using TEMPO or AZADO in conjunction with BF3·OEt2 or LiBF4 as precatalysts and tert-butyl nitrite as a stoichiometric oxidant has been developed. The system is based on a NO+/NO· pair for nitroxide reoxidation under anaerobic conditions. This allows the simple, high-yielding conversion of various achiral and chiral alcohols to carbonyl compounds without epimerization and no formation of nonvolatile byproducts.
- Holan, Martin,Jahn, Ullrich
-
supporting information
p. 58 - 61
(2014/01/23)
-
- 4-Benzamido-TEMPO catalyzed oxidation of a broad range of alcohols to the carbonyl compounds with NaBrO3 under mild conditions
-
4-Benzamido-TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO3 under room temperature conditions has been developed. The credible, operationally convenient and economical, and condition mild oxidation protocol is particularly of interest in laboratory and in fine chemicals manufacture. 4-Benzamido-TEMPO catalyzed oxidation system for conversion of a wide range of alcohols to the aldehydes or ketones with NaBrO3 as oxidant under room temperature conditions has been developed. Copyright
- Shen, Jiaxuan,Sun, Jiangkai,Qin, Shuangshuang,Chu, Changhu,Liu, Renhua
-
p. 405 - 409
(2014/06/10)
-
- Sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals as an extraa?ordinary oxidant for primary and secondary alcohols
-
Sodium hypochlorite pentahydrate crystals containing less free sodium hydroxide and sodium chloride have been developed as an improved oxidant. Primary and secondary alcohols have been oxidized to the corresponding aldehydes and ketones with ?NaOCl·5H2O in the presence of TEMPO/Bu4NHSO4. This new oxidation method does not require pH adjustment and is applicable to sterically hindered secondary alcohols. Georg Thieme Verlag Stuttgart New York.
- Okada, Tomohide,Asawa, Tomotake,Sugiyama, Yukihiro,Kirihara, Masayuki,Iwai, Toshiaki,Kimura, Yoshikazu
-
p. 596 - 598
(2014/03/21)
-
- Activation of DMSO for Swern-type oxidation by 1,1-dichlorocycloheptatriene
-
A new dimethylsulfoxide activation method employing 1,1-dichlorocycloheptatriene has been developed for a mild Swern-type oxidation of a variety of alcohols. The carbonyl products can be obtained in good to excellent yields from this operationally simple and efficient method. This work is the first report of dimethylsulfoxide activation by a simple chlorinated hydrocarbon reagent, which has the unique ability of equilibrating to its reactive aromatic cationic form.
- Nguyen, Thanh Vinh,Hall, Michael
-
supporting information
p. 6895 - 6898
(2015/01/09)
-
- Selective oxidation of alcohols with alkali metal bromides as bromide catalysts: Experimental study of the reaction mechanism
-
A bromide-catalyzed oxidation of alcohols was developed which proceeded in the presence of an alkali metal bromide and an oxidant under mild conditions. The reaction involved an organic-molecule-free oxidation using KBr and Oxone and a Br?nsted acid assisted oxidation using KBr and aqueous H 2O2 solution to provide a broad range of carbonyl compounds in high yields. Moreover, the bromide-catalyzed oxidation of primary alcohols enabled the divergent synthesis of carboxylic acids and aldehydes under both reaction conditions in the presence of TEMPO. A possible catalytic mechanism was suggested on the basis of various mechanistic studies.
- Moriyama, Katsuhiko,Takemura, Misato,Togo, Hideo
-
p. 6094 - 6104
(2014/07/21)
-
- Intramolecular hydrogen transfer reaction: Menthon from isopulegol
-
The flavor menthon (isomeric mixture of (-)-menthon and (+)-isomenthon) was obtained in good yields and selectivities by a solventless ruthenium catalyzed isomerization of the homoallylic alcohol (-)-isopulegol. In contrast to most previous assumptions on such isomerization reactions, this reaction follows an intermolecular pathway, with menthol and pulegon being the central intermediates in this transformation.
- Schaub, Thomas,Ruedenauer, Stefan,Weis, Martine
-
supporting information
p. 2575 - 2577
(2014/06/09)
-
- 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)
-
- Biocatalytic asymmetric alkene reduction: Crystal structure and characterization of a double bond reductase from Nicotiana tabacum
-
The application of biocatalysis for the asymmetric reduction of activated C=C is a powerful tool for the manufacture of high-value chemical commodities. The biocatalytic potential of "-ene" reductases from the Old Yellow Enzyme (OYE) family of oxidoreductases is well-known; however, the specificity of these enzymes toward mainly small molecule substrates has highlighted the need to discover "-ene" reductases from different enzymatic classes to broaden industrial applicability. Here, we describe the characterization of a flavin-free double bond reductase from Nicotiana tabacum (NtDBR), which belongs to the leukotriene B4 dehydrogenase (LTD) subfamily of the zinc-independent, medium chain dehydrogenase/reductase superfamily of enzymes. Using steady-state kinetics and biotransformation reactions, we have demonstrated the regio- and stereospecificity of NtDBR against a variety of α,β-unsaturated activated alkenes. In addition to catalyzing the reduction of typical LTD substrates and several classical OYE-like substrates, NtDBR also exhibited complementary activity by reducing non-OYE substrates (i.e., reducing the exocyclic C=C double bond of (R)-pulegone) and in some cases showing an opposite stereopreference in comparison with the OYE family member pentaerythritol tetranitrate (PETN) reductase. This serves to augment classical OYE "-ene" reductase activity and, coupled with its aerobic stability, emphasizes the potential industrial value of NtDBR. Furthermore, we also report the X-ray crystal structures of the holo-, binary NADP(H)-bound, and ternary [NADP+ and 4-hydroxy-3-methoxycinnamaldehyde (9a)-bound] NtDBR complexes. These will underpin structure-driven site-saturated mutagenesis studies aimed at enhancing the reactivity, stereochemistry, and specificity of this enzyme.
- Mansell, David J.,Toogood, Helen S.,Waller, John,Hughes, John M.X.,Levy, Colin W.,Gardiner, John M.,Scrutton, Nigel S.
-
p. 370 - 379
(2013/08/25)
-
- Tetrabutylammonium prolinate-based ionic liquids: A combined asymmetric catalysis, antimicrobial toxicity and biodegradation assessment
-
Chiral ionic liquids (CILs) tetrabutylammonium-(S)-prolinate, tetrabutylammonium-(R)-prolinate and tetrabutylammonium trans-4-hydroxy-(S)- prolinate were investigated as chiral additives in the Pd-catalyzed enantioselective hydrogenation of α,β-unsaturated ketones. These CILs were easily prepared in one step from the aminoacid and tetrabutylammonium hydroxide and characterized (NMR, IR, optical rotation, elemental analysis, DSC, viscosity, decomposition temperature). The research strategy was to assess the antimicrobial toxicity (>20 strains) and biodegradability (OECD 301D) of the CILs at the same time as undertaking the asymmetric catalysis study. The Pd-catalyzed enantioselective hydrogenation of the carbon-carbon double bond of α,β-unsaturated ketones under mild conditions (room temperature, 1 atm of H2) in different solvents with CILs present. The best results were obtained in i-PrOH after 18 hours of reaction with a i-PrOH/IL ratio of 5. While all three CILs have low antimicrobial toxicity to a wide range of bacteria and fungi, tetrabutylammonium-(S)-prolinate, tetrabutylammonium-(R)-prolinate and tetrabutylammonium trans-4-hydroxy-(S)-prolinate did not pass the Closed Bottle biodegradation test.
- Ferlin, Nadege,Courty, Matthieu,Van Nhien, Albert Nguyen,Gatard, Sylvain,Pour, Milan,Quilty, Brid,Ghavre, Mukund,Haiss, Annette,Kuemmerer, Klaus,Gathergood, Nicholas,Bouquillon, Sandrine
-
p. 26241 - 26251
(2013/12/04)
-
- METHOD FOR OXIDIZING ALCOHOLS
-
A method for oxidizing an alcohol, wherein oxidation is performed in the presence of a compound represented by the following formula (I) and a bulk oxidant, which enables efficient oxidation of secondary alcohols as well as primary alcohols, and can attain high reaction efficiency even when air is used as a bulk oxidant.
- -
-
Paragraph 0045
(2013/06/05)
-
- Efficient aerobic oxidation of secondary alcohols at ambient temperature with an ABNO/NOx catalyst system
-
New highly practical methods are presented for aerobic oxidation of secondary alcohols with a nitroxyl radical in combination with HNO3, NaNO2, or both as cocatalysts. Diverse nitroxyls are compared, including several novel bicyclic derivatives. Catalyst systems with the readily available nitroxyls, 9-azabicyclo[3.3.1]nonane-N-oxyl (ABNO) and 9-azabicyclo[3.3.1]nonan-3-one-N-oxyl (keto-ABNO), are optimized in acetic acid or acetonitrile as the solvent. The reactions are compatible with substrates bearing diverse functional groups and proceed efficiently under mild conditions at ambient pressure and temperature.
- Lauber, Markus B.,Stahl, Shannon S.
-
p. 2612 - 2616
(2013/11/19)
-
- Oxidation of alcohols to aldehydes and ketones by HIO3 in presence of NaHSO4·H2O
-
Different types of alcohols are efficiently converted to their corresponding aldehyds and ketones with HIO3 in presence of NaHSO4·H2O. All reaction was performed in CH 3CN medium in good to high yields.
- Khademian, Mohsen,Khademian, Maryam,Rahimnejad, Mostafa,Mokhtarian, Nader
-
p. 2927 - 2928
(2013/04/24)
-