- One-pot conversion of olefins to carbonyl compounds by hydroboration/NMO-TPAP oxidation
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An efficient method to oxidize an olefin to the less substituted carbonyl compound is described. This new methodology utilizes borane dimethyl sulfide followed by tetrapropylammonium perruthenate N-methylmorpholine N-oxide to oxidize the resulting alkylborane.
- Yates, Matthew H.
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- Formamides undergo in-plane bimolecular nucleophilic vinylic substitutions (S(N)2) by the reaction with (E)-alkenyl(phenyl)iodonium tetrafluoroborates: Stereoselective synthesis of (Z)-vinyl formates
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Reported for the first time is the stereoselective synthesis of (Z)-vinyl formates, which involves in-plane bimolecular nucleophilic vinylic substitutions of (E)-β-alkylvinyl(phenyl)iodonium tetrafluoroborates with formamides.
- Ochiai, Masahito,Yamamoto, Shinji,Sato, Koichi
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- A useful and catalytic method for protection of carbonyl compounds into the corresponding 1,3-oxathiolanes and deprotection to the parent carbonyl compounds
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A wide variety of carbonyl compounds 1 can be easily protected to the corresponding 1,3-oxathiolanes 2 in good yields in the presence of catalytic amount of perchloric acid in dry CH2Cl2 at 0-5 °C. On the other hand, various 1,3-oxathiolanes 2 can be selectively deprotected to the parent carbonyl compounds 1 in very good yields by H2MoO4·H2O-H2O2 catalyzed oxidation of ammonium bromide in the presence of perchloric acid in CH2Cl2-H2O solvent system. Mild reaction condition, high selectivity, efficient and relatively good yields are some of the major advantages of the procedure.
- Mondal, Ejabul,Sahu, Priti Rani,Khan, Abu T.
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- Reversal of regioselectivity in Wacker-Type oxidation of simple terminal alkenes and its paired interacting orbitals (PIO) analysis
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The trend of aldehyde selectivity observed in the oxidation of 1-decene with PdCl2(CH3CN)2/CuCl2 in alcohol (ROH) under O2 can be evaluated by the overlap populations for Pd-C and C-OR bonds in the oxypalladation step with paired interacting orbitals (PIO) analysis. The use of t-BuOH affords decanal in 84% regioselectivity.
- Ogura, Toshihiko,Kamimura, Ryuichiro,Shiga, Akinobu,Hosokawa, Takahiro
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- An exceptionally simple and convenient method for dethioacetalization
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Thioacetals derived from aldehydes and ketones can be unmasked to the corresponding carbonyl compounds in high yield on exposure to a solution of 'oxides of nitrogen' in dichloromethane.
- Mehta, Goverdhan,Uma
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- Polymer-supported Chain Homologation
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Addition of hept-1-ene to a suspension of polystyrene-bound forms of hydridocarbonyltris(triphenylphosphine)rhodium(I) and methylenetriphenylphosphorane in tetrahydrofuran, under a hydrogen/carbon monoxide atmosphere (60 deg C; 120 lb in-2), produces 2-methylheptanal (10percent), n-octanal (45percent), n-decanal (12percent), n-dodecanal (2percent), and n-tetradecanal (0.3percent) as major products.
- Regen, Steven L.,Kodomari, Mitsuo
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- Well-defined alkylpalladium complexes with pyridine-carboxylate ligands as catalysts for the aerobic oxidation of alcohols
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Neophylpalladium complexes of the type [Pd(CH2CMe 2Ph)(N-O)(L)], where N-O is picolinate or a related bidentate, monoanionic ligand (6-methylpyridine-2-carboxylate, quinoline-2-carboxylate, 2-pyridylacetate or pyridine-2-sulfonate) and L is pyridine or a pyridine derivative, efficiently catalyze the oxidation of a range of aliphatic, benzylic and allylic alcohols with oxygen, without requiring any additives. A versatile method is described which allows the synthesis of the above-mentioned complexes with a minimum synthetic effort from readily available materials. Comparison of the rates of oxidation of 1-phenylethanol with different catalysts reveals the influence of the structure of the bidentate N-O chelate and the monodentate ligand L on the catalytic performance of these complexes. The Royal Society of Chemistry 2012.
- Melero, Cristobal,Shishilov, Oleg N.,Alvarez, Eleuterio,Palma, Pilar,Campora, Juan
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- TiO2-Photocatalyzed Epoxidation of 1-Decene by H2O2 under Visible Light
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1-Decene was converted to 1,2-epoxydecane on UV-irradiated TiO2 powder using molecular oxygen as the oxygen source. Other main products were nonanal and 2-decanone. For anatase-form TiO2 powders, the reaction rate was hardly affected by addition of hydrogen peroxide to the solution. In contrast, for rutile-form TiO2 powders, the rate of epoxide generation was significantly increased by addition of hydrogen peroxide. In this case, the reaction occurred under visible light as well as UV light. The selectivity of the production of 1,2-epoxydecane was higher under visible light than under UV light. The conversion efficiency of an incident photon to 1,2-epoxydecane was about 2 percent when irradiated with visible light in the range 440-480 nm. UV-visible diffuse reflection spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy suggested the generation of a Ti-η2-peroxide on rutile TiO2 surface after treatment with hydrogen peroxide. The initial step of the reaction under visible light was attributed to a photochemical reaction of this peroxide with 1-decene.
- Ohno, Teruhisa,Masaki, Yuji,Hirayama, Seiko,Matsumura, Michio
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- Unexpected highly chemoselective deprotection of the acetals from aldehydes and not ketones: TESOTf-2,6-lutidine combination
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Acetal functions are recognized as good protecting groups of carbonyl groups. Although many deprotecting methods of acetals to carbonyl functions have already been developed, there is no methodology which can deprotect acetals in the presence of ketals because the usual acidic or radical reactions occur more easily via the more stable cationic or radical intermediates from the ketals. On the other hand, this new method can proceed in a reverse manner to that described in previous reports. That is, the method can deprotect aliphatic acetals in the presence of ketals. The reaction condition is common for silylation, i.e., the TESOTf-2,6-lutidine combinations. Although the TMSOTf-2,6-lutidine combination can also deprotect acetals, it lacks chemoselectivity in deprotection of the acetals from aldehydes and ketones. The treatment of acetals with TESOTf and 2,6-lutidine in CH2Cl2 followed by a H2O workup gave the corresponding aldehydes. Of course, the compounds, which have both acetal and hydroxyl functions afforded the compounds obtained by the usual silylation of an alcohol and deprotection of an acetal without any problem. However, deprotection of the ketals from ketones was not observed during the conversion reaction of acetals from aldehydes. This chemoselectivity was confirmed in the reactions of the compounds that have the acetal and ketal in the same molecule. In both cases, the acetal functions were deprotected to give aldehydes with intact ketals. Furthermore, under the conditions described here, many functional groups such as methoxy, acetoxy, allyl alcohol, and silyloxy ether are intact. This method is very mild and available for many compounds. Copyright
- Fujioka, Hiromichi,Sawama, Yoshinari,Murata, Nobutaka,Okitsu, Takashi,Kubo, Ozora,Matsuda, Satoshi,Kita, Yasuyuki
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- C-H functionalization of sp3centers with aluminum: A computational and mechanistic study of the baddeley reaction of decalin
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Decalin undergoes reaction with aluminum trichloride and acetyl chloride to form a tricyclic enol ether in good yield, as first reported by Baddeley. This eye-catching transformation, which may be considered to be an aliphatic Friedel-Crafts reaction, has not previously been studied mechanistically. Here we report experimental and computational studies to elucidate the mechanism of this reaction. We give supporting evidence for the proposition that, in the absence of unsaturation, an acylium ion acts as a hydride acceptor, forming a tertiary carbocation. Loss of a proton introduces an alkene, which reacts with a further acylium ion. A concerted 1,2-hydride shift/oxonium formation, followed by elimination, leads to formation of the observed product.
- Lyall, Catherine L.,Sato, Makoto,Uosis-Martin, Mario,Asghar, Syeda Farina,Jones, Matthew D.,Williams, Ian H.,Lewis, Simon E.
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- Dodecacarbonyl triiron, an efficient catalyst for photochemical isomerization of unsaturated alcohols, ethers and ester to their corresponding carbonyl compounds, enol ethers and esters
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Photochemical isomerization of unsaturated alcohols to their corresponding saturated aldehydes and ketones can be carried out efficiently by irradiaton at wavelengths > 560 nm in n-hexane at 25-30 deg C in the presence of catalytic amounts of dodecacarbonyl triiron.Unsaturated ethers and esters are likewise converted into their corresponding enol ethers and esters in moderate to high yields.Results of the reactions of benzylideneacetoneiron tricarbonyl with unsaturated compounds support the previously postulated mechanism in which the Fe(CO)3 moiety is the active species in the catalyses of the carbon-carbon double bond migration.
- Iranpoor, Nasser,Mottaghinejad, Enayatolah
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- Thiophilic addition of organolithiums to aliphatic sulfines
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Enethiolizable sulfines, freshly generated by oxidation of dithioesters, have been reacted with organolithiums. The reaction follows a selective thiophilic course leading to stabilised dithioacetal oxide carbanions, which have been subsequently treated with electrophiles. The resulting dithioacetal oxides are readily transformed into aldehydes or spontaneously to ketones. The specificity of this 'Umpolung' related chemistry is that it involves an addition reaction and not a deprotonation. Carbophilic addition has not been evidenced and enethiolization appears very limited.
- Alayrac, Carole,Cerreta, Francesca,Chapron, Isabelle,Corbin, Florence,Metzner, Patrick
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- Catalytic Effect of a BH3:N,N-Diethylaniline Complex in the Formation of Alkenyl Catecholboranes from Alk-1-ynes and Catecholborane
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Alkenyl catecholboranes are readily formed by the reaction of catecholborane and alk-1-ynes at 25 deg C, in the presence of 10 molpercent of a BH3:N,N-diethylaniline complex, via a hydroboration-alkenyl transfer mechanism.
- Suseela, Yantrapragada,Prasad, A. S. Bhanu,Periasamy, Mariappan
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- H2-Free Selective Dehydroxymethylation of Primary Alcohols over Palladium Nanoparticle Catalysts
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The dehydroxymethylation of primary alcohols is a promising strategy to transform biomass-derived oxygenates into hydrocarbon fuels. In this study, a novel, highly efficient, and reusable heterogeneous catalyst system was established for the H2-free dehydroxymethylation of primary alcohol using cerium oxide-supported palladium nanoparticles (Pd/CeO2). A wide range of aliphatic and aromatic alcohols including biomass-derived alcohols were converted into the corresponding one-carbon shorter hydrocarbons in high yields in the absence of any additives, accompanied by the production of H2 and CO. Pd/CeO2 was easily recovered from the reaction mixture and reused, retaining its high activity, thus, providing a simple and sustainable methodology to produce hydrocarbon fuels from biomass-derived oxygenates.
- Yamaguchi, Sho,Kondo, Hiroki,Uesugi, Kohei,Sakoda, Katsumasa,Jitsukawa, Koichiro,Mitsudome, Takato,Mizugaki, Tomoo
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p. 1135 - 1139
(2020/12/29)
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- DIBALH: From known fundamental to an unusual reaction; Chemoselective partial reduction of tertiary amides in the presence of esters
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This study presents a quick and reliable approach to the chemoselective partial reduction of tertiary amides to aldehydes in the presence of readily reducible ester groups using commercial DIBALH reagent. Moreover, the developed method was also extended to multi-functional molecules bearing ester moieties, which were successfully chemoselectively reduced to the corresponding aldehydes. This journal is
- An, Duk Keun,Heo, Yu Jin,Jaladi, Ashok Kumar,Kim, Hyun Tae
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p. 33809 - 33813
(2021/12/09)
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- Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
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Performing carbonylation without the use of carbon monoxide for high-value-added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear-selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
- Chen, Junjun,Hua, Kaimin,Liu, Xiaofang,Deng, Yuchao,Wei, Baiyin,Wang, Hui,Sun, Yuhan
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p. 9919 - 9924
(2021/05/31)
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- Chemo- And regioselective hydroformylation of alkenes with CO2/H2over a bifunctional catalyst
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As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway.
- Hua, Kaimin,Liu, Xiaofang,Wei, Baiyin,Shao, Zilong,Deng, Yuchao,Zhong, Liangshu,Wang, Hui,Sun, Yuhan
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supporting information
p. 8040 - 8046
(2021/11/01)
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- Unexpected Reactions of α,β-Unsaturated Fatty Acids Provide Insight into the Mechanisms of CYP152 Peroxygenases
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CYP152 peroxygenases catalyze decarboxylation and hydroxylation of fatty acids using H2O2 as cofactor. To understand the molecular basis for the chemo- and regioselectivity of these unique P450 enzymes, we analyze the activities of three CYP152 peroxygenases (OleTJE, P450SPα, P450BSβ) towards cis- and trans-dodecenoic acids as substrate probes. The unexpected 6S-hydroxylation of the trans-isomer and 4R-hydroxylation of the cis-isomer by OleTJE, and molecular docking results suggest that the unprecedented selectivity is due to OleTJE’s preference of C2?C3 cis-configuration. In addition to the common epoxide products, undecanal is the unexpected major product of P450SPα and P450BSβ regardless of the cis/trans-configuration of substrates. The combined H218O2 tracing experiments, MD simulations, and QM/MM calculations unravel an unusual mechanism for Compound I-mediated aldehyde formation in which the active site water derived from H2O2 activation is involved in the generation of a four-membered ring lactone intermediate. These findings provide new insights into the unusual mechanisms of CYP152 peroxygenases.
- Jiang, Yuanyuan,Li, Shengying,Li, Zhong,Peng, Wei,Tang, Dandan,Wang, Binju,You, Cai,Zhao, Yue
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supporting information
p. 24694 - 24701
(2021/10/14)
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- Method for reducing carboxylic acid into aldehyde compounds
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The invention discloses a method for reducing carboxylic acid into aldehyde compounds, and belongs to the field of organic chemical synthesis. Specifically, in an argon atmosphere, a carboxylic acid compound, a transition metal nickel compound, an anhydride compound, a ligand and a reducing agent are dissolved in an organic solvent, the mixture is heated and subjected to stirring reaction, after the reaction is finished, the pressure is reduced to remove the organic solvent, column chromatography separation is performed, and various aldehyde compounds are obtained. The method has the advantages of simple synthesis steps, mild reaction conditions, simplicity and easiness in operation, realization of successful reduction of the carboxylic acid compound into the aldehyde organic compounds, small use amount of the reaction catalyst, high product yield, and provision of a new approach for reduction of the carboxylic acid compound into the aldehyde compounds. Compared with a conventional method, the method has the advantages that raw materials are cheap, easy to obtain and environmentally friendly, substrate universality and functional group compatibility are improved, and the method hascertain innovativeness and unique research significance in organic synthesis methodology.
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Paragraph 0023-0026
(2020/02/27)
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- Platinum on carbon–catalyzed and chemoselective aqueous oxygen oxidation of aromatic acetals to benzoic acids
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Novel chemoselective transformations can diversify the synthetic pathways of the target molecules. The chemoselective oxidation of aromatic acetals to benzoic acid derivatives under platinum on carbon (Pt/C)–catalyzed oxygen oxidation conditions has been newly developed with a tolerance of aliphatic acetals and ketals. The present oxidation was clean and useful from the viewpoint of the easy removal of Pt/C and the use of molecular oxygen as a green oxidant in water as an abundant, non-toxic and environmentally friendly solvent.
- Yasukawa, Naoki,Matsuda, Takumi,Shimizu, Eisho,Sajiki, Hironao,Sawama, Yoshinari
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p. 145 - 152
(2020/01/28)
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- Manganese and rhenium-catalyzed selective reduction of esters to aldehydes with hydrosilanes
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The selective reduction of esters to aldehydes, via the formation of stable alkyl silyl acetals, was, for the first time, achieved with both manganese, -Mn2(CO)10- and rhenium -Re2(CO)10- catalysts in the presence of triethylsilane as reductant. These two methods provide a direct access to a large variety of aliphatic and aromatic alkyl silyl acetals (30 examples) and to the corresponding aldehydes (13 examples) upon hydrolysis. The reactions proceeded in excellent yields and high selectivity at room temperature under photo-irradiation conditions (LED, 365 nm, 40 W, 9 h).
- Wei, Duo,Buhaibeh, Ruqaya,Canac, Yves,Sortais, Jean-Baptiste
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p. 11617 - 11620
(2020/10/19)
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- Catalytic deoxygenation of bio-based 3-hydroxydecanoic acid to secondary alcohols and alkanes
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This work comprises the selective deoxygenation of bio-derivable 3-hydroxydecanoic acid to either linear alkanes or secondary alcohols in aqueous phase and H2-atmosphere over supported metal catalysts. Among the screened catalysts, Ru-based systems were identified to be most active. By tailoring the catalyst, the product selectivity could be directed to either secondary alcohols or linear alkanes. In the absence of a Br?nsted acidic additive, 2-nonanol and 3-decanol were accessible with a yield of 79% and 6% respectively, both of which can be used in food and perfume industries as flavoring agents and fragrances. To produce alkanes, we successfully synthesized a bifunctional Ru/HZSM-5 catalyst. The acidic zeolite support facilitated the dehydration of the intermediary formed alcohols to alkenes, while the following hydrogenation occurred at the Ru centers. Thus, full 3-hydroxydecanoic acid deoxygenation to nonane and decane, which are both well-established as diesel and jet fuels, was achieved with up to 72% and 12% yield, respectively.
- Artz, Jens,Brosch, Sebastian,Golchert, Christiane,Hergesell, Adrian H.,Mensah, Joel B.,Palkovits, Regina
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supporting information
p. 3522 - 3531
(2020/08/28)
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- Direct conversion of terminal alkenes to aldehydes via ozonolysis reaction in rotating zigzag bed
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In this study, continuous ozonolysis of terminal alkenes in a rotating zigzag bed was developed. Rotating zigzag bed is a new type high gravity unit relative to the previous rotating packed bed and can intensify mass transfer remarkably. The rotating zigzag bed takes advantage of centrifugal force to mix liquid and gas phase effectively. The H2O in acetone acts as an in situ reducing agent for the carbonyl oxide intermediate, providing aldehydes directly from the reaction mixture. Critical factors were investigated and achieved optimum reaction conditions. Under these conditions, the yields of series aldehydes ranged from 72.3 to 95.8percent. The discrepancy in product yields among different olefin substrates likely originates from the electronic stability of the carbonyl oxide intermediate, which is longer lived for aryl olefines with electron donor group and longer carbon chain alkene (CnH2n, n ≥ 10).
- Liang, Zhengyong,Wei, Tong,Xie, Jun,Li, Hua,Liu, Hui
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p. 2379 - 2384
(2020/05/25)
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- HYDROFORMYLATION METHOD AND CATALYST USING RHODIUM-RUTHENIUM DUAL METAL AND TETRADENTATE PHOSPHINE LIGAND
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A homogeneous catalytic reaction method and a catalyst for isomerization and hydroformylation of long-chain internal olefins are disclosed. A rhodium-ruthenium metal complex is used as a catalyst; and the ligands are tetradentate phosphine ligands. By means of the catalytic system, homogeneous internal olefin isomerization aid hydroformylation can be performed under a certain temperature and pressure to obtain aldehyde products having high normal to iso ratios. The present invention is applicable to not only long-chain internal olefins (≥C8) but also internal olefins having a carbon number less than 8.
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Paragraph 0044
(2019/11/19)
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- Biocatalytic N-Alkylation of Amines Using Either Primary Alcohols or Carboxylic Acids via Reductive Aminase Cascades
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The alkylation of amines with either alcohols or carboxylic acids represents a mild and safe alternative to the use of genotoxic alkyl halides and sulfonate esters. Here we report two complementary one-pot systems in which the reductive aminase (RedAm) from Aspergillus oryzae is combined with either (i) a 1° alcohol/alcohol oxidase (AO) or (ii) carboxylic acid/carboxylic acid reductase (CAR) to affect N-alkylation reactions. The application of both approaches has been exemplified with respect to substrate scope and also preparative scale synthesis. These new biocatalytic methods address issues facing alternative traditional synthetic protocols such as harsh conditions, overalkylation and complicated workup procedures.
- Ramsden, Jeremy I.,Heath, Rachel S.,Derrington, Sasha R.,Montgomery, Sarah L.,Mangas-Sanchez, Juan,Mulholland, Keith R.,Turner, Nicholas J.
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p. 1201 - 1206
(2019/01/21)
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- Copper diisobutyl-t-butoxyaluminum hydride: A novel reagent for chemoselective reduction of tertiary amides over esters
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We demonstrate that copper diisobutyl-t-butoxyaluminum hydride, readily prepared from lithium diisobutyl-t-butoxyaluminum hydride and CuI, effectively and chemoselectively reduces tertiary amides over esters at ambient temperature, affording the corresponding aldehydes in excellent yields.
- Im, So Hee,Shin, Won Kyu,Jaladi, Ashok Kumar,An, Duk Keun
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p. 2335 - 2340
(2018/05/16)
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- Thermal, Catalytic Conversion of Alkanes to Linear Aldehydes and Linear Amines
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Alkanes, the main constituents of petroleum, are attractive feedstocks for producing value-added chemicals. Linear aldehydes and amines are two of the most important building blocks in the chemical industry. To date, there have been no effective methods for directly converting n-alkanes to linear aldehydes and linear amines. Here, we report a molecular dual-catalyst system for production of linear aldehydes via regioselective carbonylation of n-alkanes. The system is comprised of a pincer iridium catalyst for transfer-dehydrogenation of the alkane using t-butylethylene or ethylene as a hydrogen acceptor working sequentially with a rhodium catalyst for olefin isomerization-hydroformylation with syngas. The system exhibits high regioselectivity for linear aldehydes and gives high catalytic turnover numbers when using ethylene as the acceptor. In addition, the direct conversion of light alkanes, n-pentane and n-hexane, to siloxy-terminated alkyl aldehydes through a sequence of Ir/Fe-catalyzed alkane silylation and Ir/Rh-catalyzed alkane carbonylation, is described. Finally, the Ir/Rh dual-catalyst strategy has been successfully applied to regioselective alkane aminomethylation to form linear alkyl amines.
- Tang, Xinxin,Jia, Xiangqing,Huang, Zheng
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supporting information
p. 4157 - 4163
(2018/03/29)
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- Chemoselective Reduction of Sterically Demanding N,N-Diisopropylamides to Aldehydes
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A sequential one-pot process for chemoselectively reducing sterically demanding N,N-diisopropylamides to aldehydes has been developed. In this reaction, amides are activated with EtOTf to form imidates, which are reduced with LiAlH(OR)3 [R = t-Bu, Et] to give aldehydes by hydrolysis of the resulting hemiaminals. The non-nucleophilic base 2,6-DTBMP remarkably improves reaction efficiency. The combination of EtOTf/2,6-DTBMP and LiAlH(O-t-Bu)3 was found to be optimal for reducing alkyl, alkenyl, alkynyl, and 2-monosubstituted aryl N,N-diisopropylamides. In contrast, EtOTf and LiAlH(OEt)3 in the absence of base were found to be optimal for reducing extremely sterically demanding 2,6-disubstituted N,N-diisopropylbenzamides. The reaction tolerates various reducible functional groups, including aldehyde and ketone. 1H NMR studies confirmed the formation of imidates stable in water. The synthetic usefulness of this methodology was demonstrated with N,N-diisopropylamide-directed ortho-metalation and C-H bond activation.
- Xiao, Peihong,Tang, Zhixing,Wang, Kai,Chen, Hua,Guo, Qianyou,Chu, Yang,Gao, Lu,Song, Zhenlei
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p. 1687 - 1700
(2018/02/23)
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- Efficient water-soluble catalytic system RhI-CAP for biphasic hydroformylation of olefins
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Rhodium-catalysed hydroformylation of styrene and aliphatic olefins under biphasic conditions in the presence of watersoluble 1,4,7-triaza-9-phosphatricyclo[5.3.2.14,9]tridecane (CAP) chemoselectively affords aldehydes. Multiple catalyst reuse without loss in performance is demonstrated.
- Eliseev, Oleg L.,Bondarenko, Tatyana N.,Britvin, Sergey N.,Khodorchenko, Polina P.,Lapidus, Albert L.
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p. 264 - 266
(2018/06/01)
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- Formation of potentially toxic carbonyls during oxidation of triolein in the presence of alimentary antioxidants
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Abstract: A relation between oil uptake and cancer as well as induction of hepatic inflammation was shown earlier. It is discussed that the main oil oxidation products—hydroperoxides and carbonyls—might be the reason for the mentioned diseases. In this manuscript quantitative determination of aldehydes which are formed during oxidation of triolein—as a model substance—using the Rancimat 679 is described. The oxidation of 11?g of triolein is carried out at 120?°C sparging air with a flow of 20?dm3/h for 10?h. A series of aliphatic aldehydes starting from hexanal to decanal as well as decenal was identified by LC–MS/MS and quantified as DNPH derivatives. In addition, the total amount of carbonyls was determined. Based on the calibration with hexanal, all other dominant substances were in the similar concentration range with maximum concentrations of 1.6?μmol/cm3 of hexanal, 2.3?μmol/cm3 of heptanal, 2.5?μmol/cm3 of octanal, 3.2?μmol/cm3 of nonanal, 4.0?μmol/cm3 of decanal after 6?h. The total amount of carbonyls reached a maximum after 6?h being 27?μmol/cm3 for triolein without antioxidant. The results of this investigation will be a basis for further toxicological studies on oxidized oils.
- Damanik, Marini,Murkovic, Michael
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p. 2031 - 2035
(2017/10/26)
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- Effect of the presence of ionic liquid during the NiMoS bulk preparation in the transformation of decanoic acid
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The impact of the presence and amount of [BMIM][NTf2] ionic liquid during the preparation of bulk NiMoS catalysts was investigated. It was clearly shown that these factors have a strong influence on both the morphology and specific surface area of the obtained NiMoS samples. Most interestingly the catalytic activity for the transformation of decanoic acid increased up to three times when IL was present during synthesis. In the same time, a greater selectivity towards hydrocarbons was observed. On the whole a clear relationship between catalytic activity, selectivity and NiMoS morphology was demonstrated. Consequently, it is possible to modify the morphology of the materials and impact the catalytic properties by changing the synthesis conditions.
- Leyral, Géraldine,Brillouet, Soizic,Rousseau, Julie,Richard, Frédéric,Mamede, Anne Sophie,Courthéoux, Laurence,Pradel, Annie,Ribes, Michel,Brunet, Sylvette
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p. 120 - 132
(2017/01/11)
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- A TEMPO-like nitroxide combined with an alkyl-substituted pyridine: An efficient catalytic system for the selective oxidation of alcohols with iodine
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An efficient method for the oxidation of alcohols to aldehydes or ketones in a two-phase CH2Cl2/NaHCO3 (aq.) system, using iodine and catalytic amounts of 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxyl and 2,4,6-trimethylpyridine, was developed. The performance of the method was demonstrated by the selective oxidation of 37 variously substituted alcohols in ≥90% yield, including the gram-scale synthesis of the important chemical 2,5-diformylfuran from biomass-derived 5-hydroxylmethylfurfural.
- Kashparova, Vera P.,Klushin, Victor A.,Zhukova, Irina Yu.,Kashparov, Igor S.,Chernysheva, Daria V.,Il'chibaeva, Irina B.,Smirnova, Nina V.,Kagan, Efim Sh.,Chernyshev, Victor M.
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supporting information
p. 3517 - 3521
(2017/10/05)
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- Properties and applications of sodium 2-alkyl-5-(ethoxycarbonyl)-1,3-dioxane-5-carboxylate synthesized with nano-sulfonated carbon
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A series of novel sodium 2-alkyl-5-(ethoxycarbonyl)-1,3-dioxane-5-carboxylate surfactants were synthesized in high yield using nanosolid superacid sulfonated carbon as a catalyst and characterized by 1H NMR, IR and elemental analysis. Critical micelle concentration (CMC) of the surfactants was determined and the results showed that the CMC values were less than 1.0 × 10-3 mol/L. Other relevant surface properties were also evaluated, such as emulsion stability, foam ability and degradability. In relation to emulsion formation, foam stability and the range of application of temperature, the new surfactants showed better properties than traditional surfactants when used as an emulsifier in emulsion polymerization. Moreover, the surfactants were stable under alkaline and neutral conditions, and degraded into raw materials under acid condition. Convenient synthesis process with high yield and superior properties promisingly make the title compounds to be a type of 'environmentally friendly' surfactants.
- Yuan, Lin,Li, Zhong Yan,Zhang, Min,Yuan, Xian You,Zhu, Xiao Qing
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p. 2201 - 2205
(2017/01/28)
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- A Sequential Homologation of Alkynes and Aldehydes for Chain Elongation with Optional 13C-Labeling
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Terminal alkynes (RCCH) are homologated by a sequence of ruthenium-catalyzed anti-Markovnikov hydration of alkyne to aldehyde (RCH2CHO), followed by Bestmann-Ohira alkynylation of aldehyde to chain-elongated alkyne (RCH2CCH). Inverting the sequence by starting from aldehyde brings about the reciprocal homologation of aldehydes instead. The use of 13C-labeled Bestmann-Ohira reagent (dimethyl ((1-13C)-1-diazo-2-oxopropyl)phosphonate) for alkynylation provides straightforward access to singly or, through additional homologation, multiply 13C-labeled alkynes. The labeled alkynes serve as synthetic platform for accessing a multitude of specifically 13C-labeled products. Terminal alkynes with one or two 13C-labels in the alkyne unit have been submitted to alkyne-azide click reactions; the copper-catalyzed version (CuAAC) was found to display a regioselectivity of >50 000:1 for the 1,4- over the 1,5-triazine isomer, as shown analytically by 13C NMR spectroscopy.
- Brunner, Andreas,Hintermann, Lukas
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supporting information
p. 2787 - 2792
(2016/02/27)
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- Non-plasmonic metal nanoparticles as visible light photocatalysts for the selective oxidation of aliphatic alcohols with molecular oxygen at near ambient conditions
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Nanoparticles (NPs) of Pd and Pt were used for the selective oxidation of aliphatic alcohols with molecular oxygen as an oxidant at near ambient temperatures under visible light irradiation. Distinct final products were obtained under identical reaction conditions, aliphatic esters formed over the Pd NPs while aldehydes formed over the Pt NPs. The reason for this different product selectivity is proven to be due to the much stronger interaction of Pd NPs with alcohol and aldehyde compared to Pt NPs. The photocatalytic activity is tuneable by light intensity or a moderate change in the reaction temperature.
- Tana, Tana,Guo, Xiao-Wei,Xiao, Qi,Huang, Yiming,Sarina, Sarina,Christopher, Phillip,Jia, Jianfeng,Wu, Haishun,Zhu, Huaiyong
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p. 11567 - 11570
(2016/10/03)
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- A functionalized phosphine merit preparation of ionic liquids and its application in the hydroformylation reaction
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The invention relates to synthesis of first-class phosphorus functionalized polyether alkyl guanidinium ionic liquid, and an application of the first-class phosphorus functionalized polyether alkyl guanidinium ionic liquid in a homogeneous catalytic reaction. The functionalized ionic liquid of such class can be easily prepared by an ion exchange reaction between the polyether alkyl guanidinium ionic liquid and sulfonic acid type water soluble phosphine ligand. The designed phosphorus functionalized ionic liquid can be applied to organic reactions, including hydroformylation, hydroesterification, hydrocarboxylation and catalytic hydrogenation under the catalyzing of a transition metal; the dosage of the ionic liquid used in the catalytic reaction can be decreased; the activity of the catalytic reaction can be improved; a catalyst can be separated and cycled simply and conveniently.
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Paragraph 0071; 0072; 0073
(2017/11/08)
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- Method of manufacturing calbonyl compd.
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PROBLEM TO BE SOLVED: To provide a method of manufacturing a carbonyl compound by smoothly performing a dehydrogenation reaction while preventing side reactions.SOLUTION: A method of manufacturing a carbonyl compound includes a process of converting alcohol to aldehyde or ketone by irradiating visible light to a reaction system containing a primary alcohol or a secondary alcohol, SrTiOcarrying a Ru atom and doped with Rh atom, and water.
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Paragraph 0051; 0053
(2018/06/30)
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- Conversion of Aldehyde to Alkane by a Peroxoiron(III) Complex: A Functional Model for the Cyanobacterial Aldehyde-Deformylating Oxygenase
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Cyanobacterial aldehyde-deformylating oxygenase (cADO) converts long-chain fatty aldehydes to alkanes via a proposed diferric-peroxo intermediate that carries out the oxidative deformylation of the substrate. Herein, we report that the synthetic iron(III)-peroxo complex [FeIII(η2-O2)(TMC)]+ (TMC = tetramethylcyclam) causes a similar transformation in the presence of a suitable H atom donor, thus serving as a functional model for cADO. Mechanistic studies suggest that the H atom donor can intercept the incipient alkyl radical formed in the oxidative deformylation step in competition with the oxygen rebound step typically used by most oxygenases for forming C-O bonds. (Chemical Equation Presented).
- Shokri, Alireza,Que, Lawrence
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p. 7686 - 7691
(2015/07/02)
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- Palladium on carbon-catalyzed aqueous transformation of primary alcohols to carboxylic acids based on dehydrogenation under mildly reduced pressure
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The catalytic dehydrogenation of alcohols to carbonyl products is a green sustainable oxidation with no production of waste except for hydrogen, which can be an energy source. Additionally, a reusable heterogeneous catalyst is valuable from the viewpoint of process chemistry and water is a green solvent. We have accomplished the palladium on carbon (Pd/C)-catalyzed dehydrogenation of primary alcohols to carboxylic acids in water under a mildly reduced pressure (800 hPa). The reduced pressure can be easily controlled by the vacuum controller of the rotary evaporator to remove the excess of generated hydrogen, which causes the reduction (reverse reaction) of aldehydes to alcohols (starting materials) and other undesirable side reactions. The present method is applicable to the reaction of various aliphatic and benzylic alcohols to the corresponding carboxylic acids, and the Pd/C could be reused at least 5 times.
- Sawama, Yoshinari,Morita, Kosuke,Asai, Shota,Kozawa, Masami,Tadokoro, Shinsuke,Nakajima, Junichi,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 1205 - 1210
(2015/04/22)
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- A practical in situ generation of the schwartz reagent. reduction of tertiary amides to aldehydes and hydrozirconation
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A new, highly efficient in situ protocol (Cp2ZrCl2/LiAlH(OBu-t)3) is described for the generation of the Schwartz reagent which provides a convenient method for the amide to aldehyde reduction and the regioselective hydrozirconation-iodination of alkynes and alkenes. Highlighted are chemoselective reductions of benzamides derived by directed ortho metalation (DoM) chemistry, allowing the synthesis of valuable 1,2,3-substituted benzaldehydes. The single-step, three-component process proceeds in a very short reaction time, shows excellent functional group compatibility, and uses inexpensive and long-storage stable reducing reagents.
- Zhao, Yigang,Snieckus, Victor
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p. 390 - 393
(2014/04/03)
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- Surfactant-induced substrate selectivity in the palladium-nanoparticle- mediated chemoselective hydrogenation of unsaturated aldehydes in water
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A hundred-fold substrate selectivity was observed in the competitive chemoselective hydrogenation of seven α,β-unsaturated aldehydes from C4 to C10 in water with palladium nanoparticles stabilized by sodium dodecyl sulfonate as the surfactant. The medium makes the longer lipophilic substrates hundreds of times more reactive than the shorter more hydrophilic ones, whereas in an organic medium almost no difference is observed. Something in the water: A hundred-fold substrate selectivity is observed in the competitive chemoselective hydrogenation of seven α,β-unsaturated aldehydes (C4-C10) in water with palladium nanoparticles stabilized by sodium dodecyl sulfonate as a surfactant. The medium makes the longer lipophilic substrates hundreds of times more reactive than the shorter more hydrophilic ones, whereas in an organic medium almost no difference is observed.
- La Sorella, Giorgio,Canton, Patrizia,Strukul, Giorgio,Scarso, Alessandro
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p. 1575 - 1578
(2014/06/24)
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- Broad-spectrum catalysts for the ambient temperature anti-Markovnikov hydration of alkynes
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Anti-Markovnikov alkyne hydration provides a valuable route to aldehydes. Half-sandwich ruthenium complexes ligated by 5,5′-bis(trifluoromethyl)-2, 2′-bipyridine are remarkably active for this transformation. In the presence of 2 mol % metal, a wide range of functionalized aliphatic and aromatic alkynes are hydrated in high yield at ambient temperature. Alkyne hydration: Half-sandwich ruthenium complexes derived from 5,5′-bis(trifluoromethyl)- 2,2′-bipyridine show a high activity for the anti-Markovnikov hydration of terminal alkynes (see picture). A wide array of alkynes are efficiently hydrated to aldehydes using 2 mol % metal loadings at 25 °C within 8-24 h.
- Li, Le,Zeng, Mingshuo,Herzon, Seth B.
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supporting information
p. 7892 - 7895
(2014/08/05)
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- Pd(II)-catalyzed deprotection of acetals and ketals containing acid sensitive functional groups
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The pincer complex [Pd(C1,O1,N1-L)(NCMe)] ClO4 (L = monoanionic ligand resulting from deprotonation of the acetyl group of the dimethyl monoketal of 2,6-diacetylpyridine) is used for the high-yield and selective catalytic hydrolysis of aliphatic, aromatic, cyclic, and acyclic dimethyl-acetals, -ketals, and dioxolanes, even in the presence of large substituents. Other protecting groups, such as THP or TBDMS, or very acid-sensitive alcohols were not affected. The catalyst is easily prepared in high yield from Pd(AcO)2 and 2,6-diacetylpyridinium perchlorate stable to air and moisture, easily and fully recoverable and reusable.
- Juliá-Hernández, Francisco,Arcas, Aurelia,Vicente, José
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p. 1141 - 1144
(2014/02/14)
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- Methylformate as replacement of syngas in one-pot catalytic synthesis of amines from olefins
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A new general approach for the one-pot hydroaminomethylation of olefins using methylformate as formylating agent instead of synthesis gas (syngas) has been proposed. Herein we report that a Ru-Rh catalytic system demonstrates high activity in a tandem conversion of a series of n-alkenes into amines using methylformate with yields 58-92% (6 h). The selectivity for the normal amine reached 96% with catalysis by the Ru carbonyl complex Ru3(CO) 12, with an overall yield of 55% with respect to amine in this instance. The addition of the Rh complex to Ru catalytic system, sharply increased the hydroaminomethylation rate of both the terminal and internal alkenes and increased the yield of amines to 82-93% (6-12 h). The Royal Society of Chemistry.
- Karakhanov, Eduard,Maksimov, Anton,Kardasheva, Yulia,Runova, Elena,Zakharov, Roman,Terenina, Maria,Kenneally, Corey,Arredondo, Victor
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p. 540 - 547
(2014/02/14)
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- Simple, chemoselective hydrogenation with thermodynamic stereocontrol
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Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad functional group compatibility and rapid reaction rates at standard temperature and pressure.
- Iwasaki, Kotaro,Wan, Kanny K.,Oppedisano, Alberto,Crossley, Steven W. M.,Shenvi, Ryan A.
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supporting information
p. 1300 - 1303
(2014/02/14)
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- Selective reduction of carboxylic acids to aldehydes catalyzed by B(C 6F5)3
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B(C6F5)3 efficiently catalyzes hydrosilylation of aliphatic and aromatic carboxylic acids to produce disilyl acetals under mild conditions. Catalyst loadings can be as low as 0.05 mol %, and bulky tertiary silanes are favored to give selectively the acetals. Acidic workup of the disilyl acetals results in the formation of aldehydes in good to excellent yields.
- Bezier, David,Park, Sehoon,Brookhart, Maurice
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p. 496 - 499
(2013/03/29)
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- Rapid oxidation of organic halides with N-methylmorpholine N-oxide in an ionic liquid under microwave irradiation
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A simple and rapid method for the conversion of organic halides into carbonyl derivatives is developed via microwave-assisted oxidation with N-methylmorpholine N-oxide in an ionic liquid. A variety of halide substrates are oxidized to the corresponding products in good to excellent yields in short reaction times. The ionic liquid is recovered and reused in several reaction cycles without any significant loss in activity.
- Khumraksa, Bannarak,Phakhodee, Wong,Pattarawarapan, Mookda
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supporting information
p. 1983 - 1986
(2013/04/10)
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- Uncovering the importance of proton donors in TmI2-promoted electron transfer: Facile C-N bond cleavage in unactivated amides
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Nonclassical lanthanide(II) iodides are modern reagents for the development of challenging electron-transfer processes. It was demonstrated that alcohols are critical for the formation of a thermodynamically more powerful reductant from TmI2 (thulium diiodide), the first nonclassical lanthanide(II) iodide in the series (TmI2, DyI2, NdI2). The TmI2(ROH)n reagent promotes an unprecedented cleavage of the σ C-N bond in amides. Copyright
- Szostak, Michal,Spain, Malcolm,Procter, David J.
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supporting information
p. 7237 - 7241
(2013/07/26)
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- Selective reduction of esters to aldehydes under the catalysis of well-defined NHC-iron complexes
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On a direct course to the aldehyde: Hydrosilylation catalyzed by a well-defined N-heterocyclic-carbene-iron complex under UV irradiation enabled the selective reduction of esters to aldehydes (see scheme; Bn=benzyl, Mes=mesityl). The low catalyst loading and very mild reaction conditions make this chemoselective transformation a promising alternative to the reduction of esters with diisobutylaluminum hydride. Copyright
- Li, Haoquan,Misal Castro, Luis C.,Zheng, Jianxia,Roisnel, Thierry,Dorcet, Vincent,Sortais, Jean-Baptiste,Darcel, Christophe
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supporting information
p. 8045 - 8049
(2013/08/23)
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- Towards the development of a selective ruthenium-catalyzed hydroformylation of olefins
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The ruthenium-catalyzed hydroformylation of 1- and 2-octene to give preferentially the corresponding linear aldehyde is reported. The catalyst system comprising of Ru3(CO)12 and an imidazole- substituted monophosphine ligand allows for high chemo- and regioselectivity. The hydroformylation proceeds with unprecedented rates for a ruthenium-based catalyst. Copyright
- Fleischer, Ivana,Wu, Lipeng,Profir, Irina,Jackstell, Ralf,Franke, Robert,Beller, Matthias
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p. 10589 - 10594
(2013/08/23)
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- Photocatalytic synthesis of oxygenated hydrocarbons from diesel fuel for mobile deNOx application
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Photocatalytic partial oxidation of dodecane has been studied as a model reaction of diesel fuel conversion to oxygenated hydrocarbons (OHCs) as an effective nitrogen oxide (NOx) reductant in selective catalytic reduction (SCR) systems. Thus, TiO2-based photocatalysts produced OHCs composed mainly of C1-C6 aldehydes under UV irradiation, and TiO2-SiO2 mixed oxide photocatalysts showed higher selectivity and yield to OHCs than pristine TiO2 by diluting contiguous Ti sites and suppressing complete oxidation to CO2. The effects of reaction variables were studied in detail. A novel scheme of NOx after-treatment system for diesel engine exhaust line was proposed involving the new photocatalytic reaction, where on-board photocatalytic partial oxidation of a small amount of diesel fuel produced OHCs that were supplied to the deNOx system as NOx reductant. Although further improvement is needed in the selectivity for OHCs as well as the system operability, the proposed scheme could be a more environment-friendly option than the reduction by urea, currently considered the most promising technology.
- Kim, Jae Yul,Kim, Yeon Ho,Han, Suenghoon,Choi, Sun Hee,Lee, Jae Sung
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- Redox-selective generation of aldehydes and H2 from alcohols under visible light
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Photosynthetic dehydrogenation: Potential usefulness of visible-light-induced dehydrogenation of alcohols in organic synthesis was demonstrated, in which aldehydes and H2 were afforded by using Ru/SrTiO3:Rh and water (see scheme). Water was essential for the reaction. High efficiency (TON: up to 15 400 based on Rh; H2 and aldehyde evenly generated) and high selectivity were achieved. Copyright
- Liu, Zijun,Caner, Joaquim,Kudo, Akihiko,Naka, Hiroshi,Saito, Susumu
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supporting information
p. 9452 - 9456
(2013/07/26)
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- Lanthanide carboxylate frameworks: Efficient heterogeneous catalytic system for epoxidation of olefins
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Two lanthanide-based three dimensional metal-organic frameworks (MOF) viz. [Nd(HCOO)3]n (1) and [Pr(HCOO)3]n (2) have been synthesized and characterized. Both the compounds have similar structure. In this study we have demonstrated that the compounds are highly efficient in catalyzing epoxidation of various cyclic and linear olefinic substrates. MOF compounds are stable and recyclable under the reaction conditions. Notably, MOF systems are remarkably more active and selective than the corresponding lanthanide oxide in epoxidation reaction of olefins.
- Sen, Rupam,Saha, Debraj,Koner, Subratanath
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experimental part
p. 124 - 130
(2012/04/10)
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- An iron catalyzed regioselective oxidation of terminal alkenes to aldehydes
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Fe(BF4)2·6H2O with pyridine-2,6-dicarboxylic acid and PhIO can efficiently catalyze the regioselective oxidation of terminal alkene derivatives to aldehydes under mild and benign reaction conditions.
- Chowdhury, Abhishek Dutta,Ray, Ritwika,Lahiri, Goutam Kumar
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supporting information; experimental part
p. 5497 - 5499
(2012/07/01)
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- Total synthesis and antifungal activity of (2S,3R)-2-aminododecan-3-ol
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We report the total synthesis of (2S,3R)-2-aminododecan-3-ol has been achieved starting from commercially available 10-undecenoic acid. The key steps involved are Sharpless asymmetric epoxidation, Miyashita's boron-directed C-2 regioselective azidolysis, generated the asymmetric centers and in situ detosylation and reduction of azido tosylate. The antifungal activity of the synthesized (2S,3R)-2-aminododecan-3-ol was evaluated on several Candida strains and was comparable to miconazole, a standard drug.
- Vijai Kumar Reddy,Prabhavathi Devi,Prasad,Poornima,Ganesh Kumar
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p. 4678 - 4680
(2012/08/07)
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- Catalytic aminomethylation of alkenes in a dimethylformamide medium
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The hydroaminomethylation of alkenes with dimethylamine catalyzed by rhodium and ruthenium complexes in a dimethylformamide medium under synthesis-gas pressures of 2 MPa has been studied. It has been shown that the combined use of these metals leads to a significant increase in the rate of formation of amines and selectivity for n-alkyldimethylamine. It has been found that the reaction can proceed with dimethylformamide used as an aminating agent without the addition of dimethylamine. Pleiades Publishing, Ltd., 2012.
- Karakhanov,Runova,Kardasheva,Losev,Maksimov,Terenina
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experimental part
p. 179 - 185
(2012/07/28)
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- A detailed identification study on high-temperature degradation products of oleic and linoleic acid methyl esters by GC-MS and GC-FTIR
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GC-MS and GC-FTIR were complementarily applied to identify oxidation compounds formed under frying conditions in methyl oleate and linoleate heated at 180 °C. The study was focused on the compounds that originated through hydroperoxide scission that remain attached to the glyceridic backbone in fats and oils and form part of non-volatile molecules. Twenty-one short-chain esterified compounds, consisting of 8 aldehydes, 3 methyl ketones, 4 primary alcohols, 5 alkanes and 1 furan, were identified. In addition, twenty non-esterified volatile compounds, consisting of alcohols, aldehydes and acids, were also identified as major non-esterified components. Furanoid compounds of 18 carbon atoms formed by a different route were also identified in this study. Overall, the composition of the small fraction originated from hydroperoxide scission provides a clear idea of the complexity of the new compounds formed during thermoxidation and frying.
- Berdeaux, Olivier,Fontagné, Stéphanie,Sémon, Etienne,Velasco, Joaquin,Sébédio, Jean Louis,Dobarganes, Carmen
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experimental part
p. 338 - 347
(2012/06/29)
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- Synthesis of aliphatic aldehydes
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An easy procedure for synthesis of aliphatic aldehydes has been realized in heterogeneous medium from dimethyl sulfoxide, halides and bicarbonate anions. The mixture was irradiated with microwave for a short time and lead to desired products. A number of aliphatic aldehydes were obtained in mild conditions with a good yield.
- Bratulescu, George
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experimental part
p. 2233 - 2234
(2012/02/17)
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- Mixed phosphane η5-CpRuCl(PR3)2 complexes as ambifunctional catalysts for anti-markovnikov hydration of terminal alkynes
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The catalytic activity of [CpRu(L)2(MeCN)]PF6 (L = 2-diphenylphosphinopyridine with bulky groups at C-6) for anti-Markovnikov hydration of terminal alkynes to aldehydes is retained when one heterocyclic ligand L is replaced by L′ = PPh3. Equal amounts of CpRuCl(PPh3)2 (1) and phosphane L in acetone solution equilibrate to a mixture of 1, CpRuCl(L)(PPh3) (2), and CpRuCl(L)2 (3), which acts as highly active in situ catalyst for preparative anti-Markovnikov hydration of alkynes in water-rich media (2 mol % [Ru], 60 °C, 3-18 h in 4:1 (v/v) acetone/water). Reactions were completed in 15 min at 160 °C.
- Boeck, Florian,Kribber, Thomas,Xiao, Li,Hintermann, Lukas
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supporting information; experimental part
p. 8138 - 8141
(2011/07/08)
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