- Control of C-C and C-N bond cleavage of 2H-azirine by means of the excitation wavelength: Studies in matrices and in solutions
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The remarkable wavelengh-dependent photoreactions of 3-methyl-2-(1-naphthyl)-2H-azirine (1) were observed in matrices at 10 K and in solutions at room temperature. Irradiation of 1 with the long-wavelength light (366 nm) exclusively gave the products form
- Inui, Hiroshi,Murata, Shigeru
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Read Online
- One-Pot Direct Oxidation of Primary Amines to Carboxylic Acids through Tandem ortho-Naphthoquinone-Catalyzed and TBHP-Promoted Oxidation Sequence
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Biomimetic oxidation of primary amines to carboxylic acids has been developed where the copper-containing amine oxidase (CuAO)-like o-NQ-catalyzed aerobic oxidation was combined with the aldehyde dehydrogenase (ALDH)-like TBHP-mediated imine oxidation protocol. Notably, the current tandem oxidation strategy provides a new mechanistic insight into the imine intermediate and the seemingly simple TBHP-mediated oxidation pathways of imines. The developed metal-free amine oxidation protocol allows the use of molecular oxygen and TBHP, safe forms of oxidant that may appeal to the industrial application.
- Kim, Hun Young,Oh, Kyungsoo,Si, Tengda
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supporting information
p. 18150 - 18155
(2021/12/09)
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- Visible-Light-Driven Oxidative Cleavage of Alkenes Using Water-Soluble CdSe Quantum Dots
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The oxidative cleavage of C=C bonds is an important chemical reaction, which is a popular reaction in the photocatalytic field. However, high catalyst-loading and low turnover number (TON) are general shortcomings in reported visible-light-driven reactions. Herein, the direct oxidative cleavage of C=C bonds through water-soluble CdSe quantum dots (QDs) is described under visible-light irradiation at room temperature with high TON (up to 3.7×104). Under the same conditions, water-soluble CdSe QDs could also oxidize sulfides to sulfoxides with 51–84 % yields and TONs up to 3.4×104. The key features of this photocatalytic protocol include high TONs, wide substrates scope, low catalyst loadings, simple and mild reaction conditions, and molecular O2 as the oxidant.
- Li, Jianing,Zhao, Jingnan,Ma, Cunfei,Yu, Zongyi,Zhu, Hongfei,Yun, Lei,Meng, Qingwei
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p. 4985 - 4992
(2021/10/16)
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- PhIO-Mediated oxidative dethioacetalization/dethioketalization under water-free conditions
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Treatment of thioacetals and thioketals with iodosobenzene in anhydrous DCM conveniently afforded the corresponding carbonyl compounds in high yields under water-free conditions. The mechanistic studies indicate that this dethioacetalization/dethioketalization process does not need water and the oxygen of the carbonyl products comes from the hypervalent iodine reagent.
- Du, Yunfei,Ouyang, Yaxin,Wang, Xi,Wang, Xiaofan,Yu, Zhenyang,Zhao, Bingyue,Zhao, Kang
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- Tunable Artificial Enzyme-Cofactor Complex for Selective Hydrolysis of Acetals
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Enzymes frequently use unimpressive functional groups such as weak carboxylic acids for efficient, highly selective catalysis including hydrolysis of acetals and even amides. Much stronger acids generally have to be used for such purposes in synthetic systems. We report here a method to position an acidic group near the acetal oxygen of 2-(4-nitrophenyl)-1,3-dioxolane bound by an artificial enzyme. The hydrolytic activity of the resulting artificial enzyme-cofactor complex was tuned by the number and depth of the active site as well as the hydrophobicity and acidity of the cofactor. The selectivity of the complex was controlled by the size and shape of the active site and enabled less reactive acetals to be hydrolyzed over more reactive ones.
- Bose, Ishani,Fa, Shixin,Zhao, Yan
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p. 1701 - 1711
(2021/02/05)
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- Ferric ion concentration-controlled aerobic photo-oxidation of benzylic C–H bond with high selectivity and conversion
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A Fe(III)-promoted highly selective photo-oxidation of benzylic C–H bond delivering relative carbonyl products is reported. By altering the concentration of ferric salt, methylarenes can be selectively oxidized under UV irradiation to furnish aromatic aldehydes or acids, respectively. By this protocol, the oxidation of ethylarenes provides the corresponding acetophenones. The reaction is inferred to involve divergent pathways in different concentrations of catalyst for the alternative selectivity between aldehydes and aicds. The reusable catalyst, high conversion and selectivity make this oxidation a green and economic protocol for the synthesis of aromatic carbonyl compounds.
- Bu, Hongzhong,Gu, Jiefan,Li, Yufeng,Ma, Hongfei,Wan, Yuting,Wu, Zheng-Guang,Zhang, Weijian,Zhou, Ying'ao,Zhu, Hongjun
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- Merging N-Hydroxyphthalimide into Metal-Organic Frameworks for Highly Efficient and Environmentally Benign Aerobic Oxidation
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Two highly efficient metal-organic framework catalysts TJU-68-NHPI and TJU-68-NDHPI have been successfully synthesized through solvothermal reactions of which the frameworks are merged with N-hydroxyphthalimide (NHPI) units, resulting in the decoration of pore surfaces with highly active nitroxyl catalytic sites. When t-butyl nitrite (TBN) is used as co-catalyst, the as-synthesized MOFs are demonstrated to be highly efficient and recyclable catalysts for a novel three-phase heterogeneous oxidation of activated C?H bond of primary and secondary alcohols, and benzyl compounds under mild conditions. Based on the high efficiency and selectivity, an environmentally benign system with good sustainability, mild conditions, simple work-up procedure has been established for practical oxidation of a wide range of substrates.
- Wang, Man,Liang, Gan,Wang, Yunhao,Fan, Tao,Yuan, Baoling,Liu, Mingxian,Yin, Ying,Li, Liangchun
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supporting information
p. 9674 - 9685
(2021/06/09)
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- A Magnetically Recyclable Palladium-Catalyzed Formylation of Aryl Iodides with Formic Acid as CO Source: A Practical Access to Aromatic Aldehydes
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A magnetically recyclable palladium-catalyzed formylation of aryl iodides under CO gas-free conditions has been developed by using a bidentate phosphine ligand-modified magnetic nanoparticles-anchored- palladium(II) complex [2P-Fe 3O 4@SiO 2-Pd(OAc) 2] as catalyst, yielding a wide variety of aromatic aldehydes in moderate to excellent yields. Here, formic acid was employed as both the CO source and the hydrogen donor with iodine and PPh 3as the activators. This immobilized palladium catalyst can be obtained via a simple preparative procedure and can be facilely recovered simply by using an external magnetic field, and reused at least 9 times without any apparent loss of catalytic activity.
- You, Shengyong,Zhang, Rongli,Cai, Mingzhong
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p. 1962 - 1970
(2021/01/25)
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- Samarium-based Grignard-type addition of organohalides to carbonyl compounds under catalysis of CuI
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Grignard-type additions were readily achieved under the mediation of CuI (10 mol%) and samarium (2 equiv.) by employing various organohalides,e.g.benzyl, aryl, heterocyclic and aliphatic halides (Cl, Br or I), and diverse carbonyl compounds (e.g.carbonic esters, carboxylic esters, acid anhydrides, acyl chlorides, ketones, aldehydes, propylene epoxides and formamides) to afford alcohols, ketones and aldehydes, respectively, with high efficiency and chemoselectivity, in which the organosamarium intermediate might be involved.
- Liu, Chen,Liu, Yongjun,Qi, Yan,Song, Bin,Wang, Liang,Xiao, Shuhuan
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supporting information
p. 6169 - 6172
(2021/06/30)
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- Palladium-Catalyzed Reductive Carbonylation of (Hetero) Aryl Halides and Triflates Using Cobalt Carbonyl as CO Source
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An efficient protocol for the reductive carbonylation of (hetero) aryl halides and triflates under CO gas-free conditions using Pd/Co2(CO)8 and triethylsilane has been developed. The mild reaction conditions, enhanced chemoselectivity and, easy access to heterocyclic and vinyl carboxaldehydes highlights its importance in organic synthesis.
- Dogga, Bhushanarao,Joseph, Jayan T.,Kumar, C. S. Ananda
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supporting information
p. 309 - 313
(2020/12/23)
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- Potent Inhibition of Nicotinamide N-Methyltransferase by Alkene-Linked Bisubstrate Mimics Bearing Electron Deficient Aromatics
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Nicotinamide N-methyltransferase (NNMT) methylates nicotinamide (vitamin B3) to generate 1-methylnicotinamide (MNA). NNMT overexpression has been linked to a variety of diseases, most prominently human cancers, indicating its potential as a therapeutic target. The development of small-molecule NNMT inhibitors has gained interest in recent years, with the most potent inhibitors sharing structural features based on elements of the nicotinamide substrate and the S-adenosyl-l-methionine (SAM) cofactor. We here report the development of new bisubstrate inhibitors that include electron-deficient aromatic groups to mimic the nicotinamide moiety. In addition, a trans-alkene linker was found to be optimal for connecting the substrate and cofactor mimics in these inhibitors. The most potent NNMT inhibitor identified exhibits an IC50 value of 3.7 nM, placing it among the most active NNMT inhibitors reported to date. Complementary analytical techniques, modeling studies, and cell-based assays provide insights into the binding mode, affinity, and selectivity of these inhibitors.
- Buijs, Ned,Campagna, Roberto,Emanuelli, Monica,Gao, Yongzhi,Gutiérrez-De-Terán, Hugo,Innocenti, Paolo,Jespers, Willem,Martin, Nathaniel I.,Parsons, Richard B.,Sartini, Davide,Van Haren, Matthijs J.,Van Westen, Gerard J. P.,Zhang, Yurui
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p. 12938 - 12963
(2021/09/11)
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- Selective Solvent-Free and Additive-Free Oxidation of Primary Benzylic C–H Bonds with O2 Catalyzed by the Combination of Metalloporphyrin with N-Hydroxyphthalimide
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Abstract: A protocol for solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts to overcome the deficiencies encountered in current oxidation systems. The effects of reaction temperature, porphyrin structure, central metal, catalyst loading and O2 pressure were investigated systematically. For the optimized combination of T(2-OCH3)PPCo and NHPI, all the primary benzylic C–H bonds could be functionalized efficiently and selectively at 120 °C and 1.0?MPa O2 with aromatic acids as the primary products. The selectivity towards aromatic acids could reach up to 70–95% in the conversion of more than 30% for most of the substrates possessing primary benzylic C–H bonds in the metalloporphyrin loading of 0.012% (mol/mol). And the superior performance of T(2-OCH3)PPCo among the metalloporphyrins investigated was mainly attributed to its high efficiency in charge transfer and fewer positive charges around central metal Co (II) which favored the adduction of O2 to cobalt (II) forming the high-valence metal-oxo complex followed by the production of phthalimide N-oxyl radical (PINO) and the initiation of the catalytic oxidation cycle. This work would provide not only an efficient protocol in utilization of hydrocarbons containing primary benzylic C–H bonds, but also a significant reference in the construction of more efficient C–H bonds oxidation systems. Graphic Abstract: The solvent-free and additive-free oxidation of primary benzylic C–H bonds with O2 was presented through adjusting the combination of metalloporphyrins and NHPI as binary catalysts, and the highest selectivity towards aromatic acid reached up to 95.1% with the conversion of 88.5% in the optimized combination of T(2-OCH3)PPCo and NHPI.[Figure not available: see fulltext.].
- Shen, Hai-Min,Qi, Bei,Hu, Meng-Yun,Liu, Lei,Ye, Hong-Liang,She, Yuan-Bin
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p. 3096 - 3111
(2020/04/29)
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- Method for catalytic oxidation of toluene and derivatives thereof by metalloporphyrin
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The invention relates to a method for catalytic oxidation of toluene and derivatives thereof by metalloporphyrin. The method comprises the following steps: dispersing metalloporphyrin and N-hydroxyphthalimide (NHPI) into methylbenzene and derivatives thereof, sealing the reaction system, heating to 70-130 DEG C while stirring, introducing oxygen to 0.2-2.0 MPa, keeping the set temperature and oxygen pressure, carrying out reactions for 8 hours under stirring, and carrying out after-treatment on the reaction solution to obtain the product aromatic acid. The method has the advantages of no solvent, no additive, mild conditions, higher selectivity to aromatic acids and good tolerance to substrates. The method not only can effectively oxidize hydrocarbon containing primary benzyl C-H bonds, but also can provide important reference for constructing a more effective C-H bond oxidation system, and is a novel efficient and feasible selective catalytic oxidation method for methylbenzene and derivatives thereof.
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Paragraph 0071-0072
(2020/09/30)
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- Rhodium-catalyzed reductive carbonylation of aryl iodides to arylaldehydes with syngas
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The reductive carbonylation of aryl iodides to aryl aldehydes possesses broad application prospects. We present an efficient and facile Rh-based catalytic system composed of the commercially available Rh salt RhCl3·3H2O, PPh3 as phosphine ligand, and Et3N as the base, for the synthesis of arylaldehydes via the reductive carbonylation of aryl iodides with CO and H2 under relatively mild conditions with a broad substrate range affording the products in good to excellent yields. Systematic investigations were carried out to study the experimental parameters. We explored the optimal ratio of Rh salt and PPh3 ligand, substrate scope, carbonyl source and hydrogen source, and the reaction mechanism. Particularly, a scaled-up experiment indicated that the catalytic method could find valuable applications in industrial productions. The low gas pressure, cheap ligand and low metal dosage could significantly improve the practicability in both chemical researches and industrial applications.
- Chen, Suqing,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong,Yu, Dongkun,Zhao, Xinhui
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p. 645 - 656
(2020/05/14)
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- Controlled Reduction of Nitriles by Sodium Hydride and Zinc Chloride
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A new protocol for the controlled reduction of nitriles to aldehydes was developed using a combination of sodium hydride and zinc chloride. The iminyl zinc intermediates derived from aromatic nitriles could be further functionalized with allylmetal nucleophiles to afford homoallylamines. As the method allows the reduction of various aliphatic and aromatic nitriles with a concise procedure under milder reaction conditions and exhibits wide functional group compatibility, it is well suited for use in various opportunities in chemical synthesis.
- Chiba, Shunsuke,Ong, Derek Yiren
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p. 1369 - 1378
(2020/04/27)
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- Nitrile Synthesis by Aerobic Oxidation of Primary Amines and in situ Generated Imines from Aldehydes and Ammonium Salt with Grubbs Catalyst
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Herein, a Grubbs-catalyzed route for the synthesis of nitriles via the aerobic oxidation of primary amines is reported. This reaction accommodates a variety of substrates, including simple primary amines, sterically hindered β,β-disubstituted amines, allylamine, benzylamines, and α-amino esters. Reaction compatibility with various functionalities is also noted, particularly with alkenes, alkynes, halogens, esters, silyl ethers, and free hydroxyl groups. The nitriles were also synthesized via the oxidation of imines generated from aldehydes and NH4OAc in situ. (Figure presented.).
- Utsumi, Tatsuki,Noda, Kenta,Kawauchi, Daichi,Ueda, Hirofumi,Tokuyama, Hidetoshi
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p. 3583 - 3588
(2020/08/05)
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- FeCl3-catalyzed oxidative decarboxylation of aryl/heteroaryl acetic acids: Preparation of selected API impurities
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There is an ever-increasing demand for impurity compounds for use in impurity profiling as regulatory agencies seek information during registration. Herein, we report the FeCl3-catalyzed oxidative decarboxylation of aryl- and heteroaryl acetic acids to the corresponding carbonyl compounds. A variety of useful aldehydes and ketones were prepared in a simple one-pot transformation by employing an environmentally benign, low-cost, and readily available iron salt. The utility of this method has been demonstrated by preparing five valuable API impurities including a multi-gram-scale synthesis of ketorolac impurity B for the first time. This journal is
- Gangadurai, Chinnakuzhanthai,Illa, Giri Teja,Reddy, D. Srinivasa
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p. 8459 - 8466
(2020/11/05)
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- Visible-light-promoted oxidative decarboxylation of arylacetic acids in air: Metal-free synthesis of aldehydes and ketones at room temperature
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A metal-free photocatalytic oxidative decarboxylation reaction at room temperature was developed for the synthesis of aromatic aldehydes and ketones from the corresponding arylacetic acids. The reaction was realized under blue-light irradiation by adding 1 molpercent of 4CzIPN as photocatalyst and air as oxidant. This reaction represents a novel decarboxylation of a sp3-hybridized carboxylic acids without traditional heating, additional oxidants, and metal reagents under mild conditions.
- He, Shuaiqi,Chen, Xiaolan,Zeng, Fanlin,Lu, Peipei,Peng, Yuyu,Qu, Lingbo,Yu, Bing
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supporting information
p. 1863 - 1867
(2020/01/03)
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- Visible-light assisted of nano Ni/g-C3N4 with efficient photocatalytic activity and stability for selective aerobic C?H activation and epoxidation
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A selective, economical, and ecological protocol has been described for the oxidation of methyl arenes and their analogs to the corresponding carbonyl compounds and epoxidation reactions of alkenes with molecular oxygen (O2) or air as a green oxygen source, under mild reaction conditions. The nano Ni/g-C3N4 exhibited high photocatalytic activity, stability, and selectivity in the C?H activation of methyl arenes, methylene arenes, and epoxidation of various alkenes under visible- light irradiation without the use of an oxidizing agent and under base free conditions.
- Akrami, Zahra,Hosseini-Sarvari, Mona
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supporting information
(2020/10/13)
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- Cu/Ag mediated peroxide-free synthesis of benzoylated naphthol derivatives
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A peroxide-free methodology was developed for the synthesis of benzoylated naphthol/phenol derivatives through oxidative deamination reaction performed under aerobic reaction conditions. A synergistic combination of Cu(OTf)2 and Ag2O was used to convert the aminonaphthols and aminophenols to the corresponding benzoylated derivatives. The definite role of atmospheric oxygen to assist the reaction was proved by performing the reaction in the argon atmosphere.
- Prasanna Kumari, Subramaniyan,Suresh, Pavithira,Muthukumar, Vijayashree,Selva Ganesan, Subramaniapillai
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supporting information
(2020/10/13)
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- Mild environment-friendly oxidative debenzylation of N-benzylanilines using DMSO as an oxidant
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Oxidative debenzylation of N-benzyl aromatic amines using DMSO as a non-toxic oxidant and catalyzed by TsOH gave Nphenylimines, which were spontaneously hydrolyzed to form anilines and benzaldehydes in good yields. This reaction employs mild, metal-free conditions. The conditions are also suitable for the debenzylation of benzylphenylethers.
- Yoshinaga, Tatsuro,Iwata, Takayuki,Shindo, Mitsuru
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supporting information
p. 191 - 194
(2020/02/25)
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- Method for directly introducing aldehyde group to aromatic ring
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The invention relates to a method for directly introducing an aldehyde group to an aromatic ring. A purpose of the invention is mainly to solve the problems of low aromatic hydrocarbon conversion rateand low aromatic aldehyde selectivity in the prior art. According to the technical scheme, the method comprises the step of performing a carbonylation reaction on aromatic hydrocarbon and CO under the catalysis of a catalyst to obtain aromatic aldehyde, wherein the catalyst comprises a carrier, an ionic liquid and a compound-state auxiliary agent metal, the carrier is a silicon-based material, the ionic liquid comprises aluminum halide and an imidazole salt represented by a chemical formula I, R1 and R2 are independently selected from C1-C8 alkyl, X is selected from chlorine and bromine, thealuminum halide is represented as AlY3, Y is selected from chlorine and bromine, and the compound-state auxiliary metal comprises at least one selected from Cu, Fe, Cr, V and Mn.
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Paragraph 0104-0106
(2020/05/08)
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- Synthesis of silyl formates, formamides, and aldehydesviasolvent-free organocatalytic hydrosilylation of CO2
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Carbon dioxide (CO2) was used as a C1 source to prepare silyl formates, formamides, and aldehydes. Tetrabutylammonium acetate (TBAA) catalyzed the solvent-freeN-formylation of amines with CO2and hydrosilane to give formamides including Weinreb formamide, Me(MeO)NCHO, which was successively converted into aldehydes by one-pot reactions with Grignard reagents.
- Ema, Tadashi,Hasegawa, Jun-Ya,Hiyoshi, Mahoko,Murata, Takumi,Ratanasak, Manussada
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supporting information
p. 5783 - 5786
(2020/06/03)
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- Oxidative C-S Bond Cleavage of Benzyl Thiols Enabled by Visible-Light-Mediated Silver(II) Complexes
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The oxidative cleavage reaction of the C-S bond using singlet oxygen is challenging because of its uncontrollable nature. We have developed a novel method for the singlet-oxygen-mediated selective C-S bond cleavage reaction using silver(II)-ligand complexes. Visible-light-induced silver catalysis enables the controlled oxidative cleavage of benzyl thiols to afford carbonyl compounds, such as aldehydes or ketones, which are important synthetic components.
- Hong, Boseok,Aganda, Kim Christopher C.,Lee, Anna
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supporting information
p. 4395 - 4399
(2020/06/05)
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- Metal-Free Electrochemical Coupling of Vinyl Azides: Synthesis of Phenanthridines and β-Ketosulfones
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We reported an efficient and environmentally benign electrochemical synthesis of phenanthridines by oxidative coupling of vinyl azides with sodium azide or benzenesulfonyl hydrazides, for the first time. The reaction conditions are mild, and no additional metal-catalyst or exogenous oxidants are needed. The protocol has broad substrate scope and high functional group tolerance. Furthermore, this green electrochemical procedure can be readily extended to the synthesis of β-ketosulfones. Gram scale reactions further demonstrate the practicability.
- Chen, Qianjin,Kong, Xianqiang,Li, Guodong,Liang, Qi,Lin, Long,Xu, Bo,Yu, Ke
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supporting information
p. 6135 - 6145
(2020/10/06)
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- Palladium-catalyzed external-CO-free reductive carbonylation of aryl sulfonates
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Pd-catalyzed reductive carbonylation of aryl sulfonates using N-formylsaccharin as a carbon monoxide (CO) surrogate was developed. This external-CO-free carbonylation provides a safe and practical access to aldehydes from phenol derivatives. The reaction has a broad substrate scope, rendering it an attractive method for synthesizing aldehydes.
- Konishi, Hideyuki,Kumon, Minoru,Yamaguchi, Miyuki,Manabe, Kei
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- Supramolecular Catalysis of the oxa-Pictet–Spengler Reaction with an Endohedrally Functionalized Self-Assembled Cage Complex
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An endohedrally functionalized self-assembled Fe4L6 cage complex can catalyze oxa-Pictet—Spengler cyclizations of tryptophols and various aldehyde derivatives, showing strong rate accelerations and size-selectivity. Selective molecular recognition of substrates controls the reactivity, and the cage is capable of binding and activating multiple different species along the multistep reaction pathway. The combination of a functionalized active site, size-selective reactivity, and multistep activation, all from a single host molecule, illustrates the biomimetic nature of the catalysis.
- Harman, W. Hill,Hooley, Richard J.,Ngai, Courtney,Sanchez-Marsetti, Colomba M.
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supporting information
p. 23505 - 23509
(2020/10/21)
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- Photocatalytic degradation enhancement in pickering emulsions stabilized by solid particles of bare TiO2
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Pickering emulsions provide a new way to enhance the efficiency of photocatalytic degradation of water-insoluble pollutants. Indeed, the semiconductor solid particles dually act as the photocatalyst and stabilizer of the emulsion droplets whose size dramatically affects the photocatalytic reaction. The present work aims at the validation of this concept by using bare TiO2 without any surface modification. Nanostructured TiO2 has been prepared by a simple sol-gel process and characterized by X-ray diffraction, specific surface area analysis, scanning electron microscopy, and diffuse reflectance spectroscopy. The emulsions were prepared by using 1-methylnaphthalene (1-MN) as a model organic contaminant scarcely soluble in water and bare TiO2 as the photocatalyst/stabilizer. The emulsions have been characterized by electrical conductivity, optical microscopy, and light-scattering analyses. The photocatalytic degradation of 1-MN was 50 times faster in stable Pickering emulsions with respect to the case of biphasic liquid systems containing TiO2. This finding allows us to propose Pickering emulsions stabilized by TiO2 nanoparticles as an effective and novel way to intensify the photocatalytic degradation of water-insoluble organic pollutants.
- Fessi, Nidhal,Nsib, Mohamed Faouzi,Chevalier, Yves,Guillard, Chantal,Dappozze, Frédéric,Houas, Ammar,Palmisano, Leonardo,Parrino, Francesco
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p. 2129 - 2136
(2019/02/26)
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- Assessing the effectiveness of oxidative approaches for the synthesis of aldehydes and ketones from oxidation of iodomethyl group
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Owing to excellent selectivity, high yield and stability towards over-reduction and over-oxidation, one of the impressive approaches to synthesize aldehydes and ketones is the oxidation of halomethyl groups. Numerous halomethyl oxidation-based methodologies to afford aldehydes and ketones are disclosed in the literature. Mostly, chloromethyl or bromomethyl group containing substrates have been used in the literature for performing oxidation. There are negligible data available in the literature that addresses the use of iodomethyl group containing substrates for transformation to aldehydes and ketones. In this research work, 110 reactions have been carried out to construct aldehydes and ketones from oxidation of iodomethyl group in benzylic iodides and allylic iodides using numerous well-known approaches reported in the literature. The classical approaches under observation include Sommelet oxidation, Kr?hnke oxidation, sodium periodate-mediated oxidative protocol, manganese dioxide-based oxidative approach, Kornblum oxidation and Hass–Bender oxidation. The eco-friendly approaches under observation include periodic acid-based IL protocol, periodic acid in vanadium pentoxide-mediated IL method, hydrogen peroxide in vanadium pentoxide-based approach and bismuth nitrate-promoted IL technique. In this investigation, yield, recyclability, cost-effectiveness, eco-friendliness and over-oxidation are the main parameters which are under observation. Among all these investigated techniques, periodic acid-based IL protocol, periodic acid in vanadium pentoxide-mediated IL method and hydrogen peroxide in vanadium pentoxide-based approach (aka. Chunbao oxidation protocol) were found to be highly efficient due to the following reasons: these approaches (1) provide excellent yields, (2) do not lead towards over-oxidation, (3) show good recyclability, (4) demonstrate high thermal stability and negligible flammability, and (5) require no special handling.
- Faisal, Muhammad,Hussain, Sarwat,Haider, Azeem,Saeed, Aamer,Larik, Fayaz Ali
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p. 1053 - 1067
(2019/04/25)
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- CYP2C19 and 3A4 Dominate Metabolic Clearance and Bioactivation of Terbinafine Based on Computational and Experimental Approaches
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Lamisil (terbinafine) is an effective, widely prescribed antifungal drug that causes rare idiosyncratic hepatotoxicity. The proposed toxic mechanism involves a reactive metabolite, 6,6-dimethyl-2-hepten-4-ynal (TBF-A), formed through three N-dealkylation pathways. We were the first to characterize them using in vitro studies with human liver microsomes and modeling approaches, yet knowledge of the individual enzymes catalyzing reactions remained unknown. Herein, we employed experimental and computational tools to assess terbinafine metabolism by specific cytochrome P450 isozymes. In vitro inhibitor phenotyping studies revealed six isozymes were involved in one or more N-dealkylation pathways. CYP2C19 and 3A4 contributed to all pathways, and so, we targeted them for steady-state analyses with recombinant isozymes. N-Dealkylation yielding TBF-A directly was catalyzed by CYP2C19 and 3A4 similarly. Nevertheless, CYP2C19 was more efficient than CYP3A4 at N-demethylation and other steps leading to TBF-A. Unlike microsomal reactions, N-denaphthylation was surprisingly efficient for CYP2C19 and 3A4, which was validated by controls. CYP2C19 was the most efficient among all reactions. Nonetheless, CYP3A4 was more selective at steps leading to TBF-A, making it more effective in terbinafine bioactivation based on metabolic split ratios for competing pathways. Model predictions did not extrapolate to quantitative kinetic constants, yet some results for CYP3A4 and CYP2C19 agreed qualitatively with preferred reaction steps and pathways. Clinical data on drug interactions support the CYP3A4 role in terbinafine metabolism, while CYP2C19 remains understudied. Taken together, knowledge of P450s responsible for terbinafine metabolism and TBF-A formation provides a foundation for investigating and mitigating the impact of P450 variations in toxic risks posed to patients.
- Davis, Mary A.,Barnette, Dustyn A.,Flynn, Noah R.,Pidugu, Anirudh S.,Swamidass, S. Joshua,Boysen, Gunnar,Miller, Grover P.
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p. 1151 - 1164
(2019/05/01)
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- On/Off O2 Switchable Photocatalytic Oxidative and Protodecarboxylation of Carboxylic Acids
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Photoredox catalysis in recent years has manifested a powerful branch of science in organic synthesis. Although merging photoredox and metal catalysts has been a widely used method, switchable heterogeneous photoredox catalysis has rarely been considered. Herein, we open a new window to use a switchable heterogeneous photoredox catalyst which could be turned on/off by changing a simple stimulus (O2) for two opponent reactions, namely, oxidative and protodecarboxylation. Using this strategy, we demonstrate that Au@ZnO core-shell nanoparticles could be used as a switchable photocatalyst which has good catalytic activity to absorb visible light due to the localized surface plasmon resonance effect of gold, can decarboxylate a wide range of aromatic and aliphatic carboxylic acids, have multiple reusability, and are a reasonable candidate for synthesizing both aldehydes/ketones and alkane/arenes in a large-scale set up. Some biologically active molecules are also shown via examples of the direct oxidative and protodecarboxylation which widely provided pharmaceutical agents.
- Bazyar, Zahra,Hosseini-Sarvari, Mona
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p. 13503 - 13515
(2019/10/11)
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- Stepwise degradation of hydroxyl compounds to aldehydes: Via successive C-C bond cleavage
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Stepwise degradation of hydroxyl compounds to aldehydes via successive cleavage of C-C bonds was achieved by using a bimetallic catalytic system (PdCl2 + CuCl) without any ligands and additives. The broad applicability is expanded to a diverse range of aromatic, aliphatic, primary and secondary alcohols, as well as lignin model compounds.
- Liu, Mingyang,Zhang, Zhanrong,Shen, Xiaojun,Liu, Huizhen,Zhang, Pei,Chen, Bingfeng,Han, Buxing
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p. 925 - 928
(2019/01/24)
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- Iron-catalyzed oxidative C-C(vinyl) σ-bond cleavage of allylarenes to aryl aldehydes at room temperature with ambient air
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A general and selective iron-catalyzed allylic C-C(vinyl) σ-bond cleavage of allylarenes without the assistance of heteroatoms to give aryl aldehydes is reported. The unstrained carbon-carbon single bond cleavage reaction uses ambient air as the sole oxidant, proceeds efficiently at room temperature, and allows for exceptional functional-group tolerance, which addresses the long-standing challenges of current C-C bond cleavage/functionalization. Notably, the method enables rapid late-stage oxidation of complex bioactive molecules and can be used to expedite syntheses of natural products (vanillin and glucovanillin) from readily available chemical feedstocks.
- Liu, Binbin,Cheng, Lu,Hu, Penghui,Xu, Fangning,Li, Dan,Gu, Wei-Jin,Han, Wei
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p. 4817 - 4820
(2019/05/02)
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- Continuous-flow Synthesis of Aryl Aldehydes by Pd-catalyzed Formylation of Aryl Bromides Using Carbon Monoxide and Hydrogen
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A continuous-flow protocol utilizing syngas (CO and H2) was developed for the palladium-catalyzed reductive carbonylation of (hetero)aryl bromides to their corresponding (hetero)aryl aldehydes. The optimization of temperature, pressure, catalyst and ligand loading, and residence time resulted in process-intensified flow conditions for the transformation. In addition, a key benefit of investigating the reaction in flow is the ability to precisely control the CO-to-H2 stoichiometric ratio, which was identified as having a critical influence on yield. The protocol proceeds with low catalyst and ligand loadings: palladium acetate (1 mol % or below) and cataCXium A (3 mol % or below). A variety of (hetero)aryl bromides at a 3 mmol scale were converted to their corresponding (hetero)aryl aldehydes at 12 bar pressure (CO/H2=1:3) and 120 °C reaction temperature within 45 min residence time to afford products mostly in good-to-excellent yields (17 examples). In particular, a successful scale-up was achieved over 415 min operation time for the reductive carbonylation of 2-bromo-6-methoxynaphthalene to synthesize 3.8 g of 6-methoxy-2-naphthaldehyde in 85 % isolated yield. Studies were conducted to understand catalyst decomposition within the reactor by using inductively coupled plasma–mass spectrometry (ICP–MS) analysis. The palladium could easily be recovered using an aqueous nitric acid wash post reaction. Mechanistic aspects and the scope of the transformation are discussed.
- Hone, Christopher A.,Lopatka, Pavol,Munday, Rachel,O'Kearney-McMullan, Anne,Kappe, C. Oliver
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p. 326 - 337
(2018/11/23)
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- METHOD FOR PRODUCING CARBONYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing a carbonyl compound, allowing for improvement of ease of production and furthermore allowing for reduction of production cost, by positively utilizing inexpensive iodine. SOLUTION: A carbonyl compound is produced by mixing primary alcohol or secondary alcohol, and iodic acid (HIO3) in a non-solvent or an aprotic polar solvent based on the following general formula (1), where R1 is an optionally substituted linear- or branched 1-12C aliphatic group, or an optionally substituted aromatic group; R2 is a hydrogen atom, an optionally substituted linear- or branched 1-12C alkyl group, or an optionally substituted aromatic group; R1 and R2 each may be coupled with each other to form a ring of aromatic group or a non-aromatic group. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0032-0034
(2018/03/23)
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- Copper based coordination polymers based on metalloligands: Utilization as heterogeneous oxidation catalysts
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This work presents the synthesis and characterization of two Cu(ii)-based coordination polymers prepared by utilizing two different Co(iii)-based metalloligands offering appended arylcarboxylic acid groups. Both coordination polymers are three-dimensional in nature and present pores and channels filled with water molecules. Both coordination polymers function as heterogeneous catalysts for the epoxidation of various olefins using O2 while employing isobutyraldehyde as the coreductor and for peroxide-mediated oxidation of assorted benzyl alcohols. The catalytic results illustrate efficient oxidation reactions, whereas the hot-fltration test and leaching experiments indicate the true heterogeneous nature of the catalysis.
- Kumar, Gulshan,Hussain, Firasat,Gupta, Rajeev
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p. 16985 - 16994
(2019/01/03)
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- Reduction of aromatic nitriles into aldehydes using calcium hypophosphite and a nickel precursor
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Herein we report the reduction of aromatic nitriles into aldehydes with calcium hypophosphite in the presence of base and nickel(ii) complex in a water/ethanol mixture. This catalytic system reduced efficiently a series of aromatic nitriles bearing different functional groups such as -Cl, -CF3, -Br, -CH3, -OCH3, -COOCH2CH3, -OH and -CHO. The corresponding aldehydes were isolated in moderate to excellent yields (30-94%).
- Mouselmani, Rim,Hachem, Ali,Alaaeddine, Ali,Métay, Estelle,Lemaire, Marc
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supporting information
p. 6600 - 6605
(2018/09/25)
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- Reduction of N,N-Dimethylcarboxamides to Aldehydes by Sodium Hydride–Iodide Composite
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A new and concise protocol for selective reduction of N,N-dimethylamides into aldehydes was established using sodium hydride (NaH) in the presence of sodium iodide (NaI) under mild reaction conditions. The present protocol with the NaH-NaI composite allows for reduction of not only aromatic and heteroaromatic but also aliphatic N,N-dimethylamides with wide substituent compatibility. Retention of α-chirality in the reduction of α-enantioriched amides was accomplished. Use of sodium deuteride (NaD) offers a new step-economical alternative to prepare deuterated aldehydes with high deuterium incorporation rate. The NaH-NaI composite exhibits unique chemoselectivity for reduction of N,N-dimethylamides over ketones.
- Chan, Guo Hao,Ong, Derek Yiren,Yen, Zhihao,Chiba, Shunsuke
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- Metal-free hypervalent iodine/TEMPO mediated oxidation of amines and mechanistic insight into the reaction pathways
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A highly efficient metal free approach for the oxidation of primary and secondary amines to their corresponding aldehydes and ketones using PhI(OAc)2 in combination with a catalytic amount of TEMPO as an oxidizing agent is described. This protocol is rapid and provides diverse products under milder reaction conditions in excellent yields. In addition, the mechanistic study is well demonstrated by spectroscopic methods.
- Bansode, Ajay H.,Suryavanshi, Gurunath
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p. 32055 - 32062
(2018/09/29)
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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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- Fe(NO3)3·9H2O-catalyzed aerobic oxidative deoximation of ketoximes and aldoximes under mild conditions
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A mild, simple process for the effective aerobic oxidative deoximation of a wide range of ketoximes and aldoximes has been developed that utilizes Fe(NO3)3·9H2O as the single catalyst and molecular oxygen as the green oxidant. The environmentally benign protocol provides moderate to excellent yield and broad functional groups tolerance and is a valuable synthetic method for practical applications. According the relevant verification experiment, a plausible mechanism has been proposed.
- Li, Yongshu,Xu, Nizhou,Mei, Guangyao,Zhao, Yun,Zhao, Yiyong,Lyu, Jinghui,Zhang, Guofu,Ding, Chengrong
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supporting information
p. 810 - 814
(2018/08/09)
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- Photoredox-Catalyzed Decarboxylative Oxidation of Arylacetic Acids
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A photoredox-catalyzed decarboxylative oxidation of arylacetic acids, which are privileged scaffolds in pharmaceuticals, is reported herein. The established method is operationally simple and a variety of substrates are applicable, providing rapid access to dehomologated bioisosteres of common pharmaceuticals.
- Sakakibara, Yota,Cooper, Phillippa,Murakami, Kei,Itami, Kenichiro
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supporting information
p. 2410 - 2413
(2018/06/04)
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- Rhodium-Catalyzed Formylation of Aryl Halides with CO2 and H2
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The reductive formylation of aryl iodides/bromides to aryl aldehydes using CO2/H2 is presented for the first time. It was realized over a catalytic system composed of RhI3 or RhI3/Pd(dppp)Cl2 (dppp = 1,3-bis(diphenyphosphino)propane) and PPh3 in the presence of Ac2O/Et3N at 100 °C, affording aromatic aldehydes in good to excellent yields, together with good functional-group tolerance and broad substrate scope. The reaction proceeds through three cascade steps, involving HCOOH formation, CO release, and formylation of aryl halides.
- Liu, Zhenghui,Yang, Zhenzhen,Yu, Bo,Yu, Xiaoxiao,Zhang, Hongye,Zhao, Yanfei,Yang, Peng,Liu, Zhimin
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supporting information
p. 5130 - 5134
(2018/09/13)
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- Iron(III) nitrate-induced aerobic and catalytic oxidative cleavage of olefins
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Microwave-assisted catalytic oxidative cleavage of olefins using Fe(NO3)3·9H2O under O2 is reported. This reaction system is particularly effective when 9-benzylidene-9H-fluorene derivatives are used as substrates even though they are tri- and tetra-substituted olefins.
- Amaya, Toru,Fujimoto, Hayato
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supporting information
p. 2657 - 2660
(2018/06/04)
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- Palladium-Catalyzed Reductive Conversion of Acyl Fluorides via Ligand-Controlled Decarbonylation
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Ligand-controlled non-decarbonylative and decarbonylative conversions of acyl fluorides were developed using a Pd(OAc)2/Et3SiH combination. When tricyclohexylphosphine (PCy3) was used as the ligand, aldehydes were obtained as simple reductive conversion products. The use of 1,2-bis(dicyclohexylphosphino)ethane (Cy2P(CH2)2PCy2, DCPE) as the ligand, however, favored the formation of hydrocarbons, which are decarbonylative reduction products.
- Ogiwara, Yohei,Sakurai, Yuka,Hattori, Hiroyuki,Sakai, Norio
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supporting information
p. 4204 - 4208
(2018/07/29)
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- Carbocation catalysed ring closing aldehyde-olefin metathesis
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A highly efficient aldehyde-olefin metathesis catalysed by the carbocation, 4-phenylphenyl-diphenylmethylium ion, has been developed. This protocol is characterized by high yields, low catalyst loading (down to 2 mol%), good functional group compatibility and mild reaction conditions.
- Ni, Shengjun,Franzén, Johan
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supporting information
p. 12982 - 12985
(2018/11/23)
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- Method for preparing aromatic aldehyde through oxidation of aromatic alcohol with sunlight
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The invention discloses a method for preparing aromatic aldehyde through oxidation of aromatic alcohol with sunlight. According to the invention, a photoinduced Ti-assisted reduction method is employed for loading metal nanoparticles onto a semiconductor material, i.e., a TiO2 carrier material, so as to synthesize a photocatalyst, and convergent solar energy is used as a light source and heat source of reaction so as to realize high-efficiency catalytic oxidation of aromatic alcohol for preparation of aromatic aldehyde. The method provided by the invention utilizes the metal nanoparticles on the photocatalyst for generation of thermal catalytic effect, greatly increases the rate of selective oxidation reaction of aromatic alcohol without consuming other input energy sources, and solves the problem of slow reaction rate of visible-light photocatalysis technology in selective oxidation of aromatic alcohol.
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Paragraph 0022; 0023
(2018/03/28)
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- Ligandless Palladium-Catalyzed Reductive Carbonylation of Aryl Iodides under Ambient Conditions
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Ligandless palladium-catalyzed reductive carbonylation of aryl iodides for the synthesis of aromatic aldehydes has been developed. This carbonylation process proceeded effectively even under ambient temperature and pressure. In addition, this method enables successive reductive carbonylation of diiodobenzenes to furnish dialdehydes in satisfactory yields. Finally, the nature of the active catalytic species is discussed.
- Han, Wei,Liu, Binbin,Chen, Junjie,Zhou, Qing
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supporting information
p. 835 - 840
(2017/04/06)
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- N-Propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) as a green and reusable heterogeneous nanocatalyst for the chemoselective preparation and deprotection of acylals
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Abstract: N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) was simply synthesized and used as a highly efficient, environmentally friendly, and chemoselective catalyst for the synthesis of 1,1-diacetates (acylals) from the one-pot condensation reaction of various aromatic aldehydes with acetic anhydride, in high yield of products (86–96%) and short reaction time (20–60?min) under solvent-free conditions at room temperature. In addition to these results, we further studied the possibility of deprotection of the resulting acylals into benzaldehyde derivatives in this catalytic system by the addition of water. More importantly, noteworthy advantages of this study are non-use of toxic organic solvents and catalysts, simple work-up procedure, short reaction time, high yield of products, and recovery and reusability of MNPs-PSA by an external magnet. Graphical Abstract: A simple and highly efficient procedure for the protection of various aldehydes with acetic anhydride in the presence of N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) is reported. We further studied the possibility of deprotection of the resulting acylals into benzaldehyde derivatives in this catalytic system by the addition of water as a green solvent. The catalyst was reused several times without loss of its catalytic activity.
- Sajjadifar, Sami,Nasri, Parastoo
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p. 6677 - 6689
(2017/10/06)
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- Enhanced catalytic actIVity and near room temperature gas sensing properties of SnO2 nanoclusters@mesoporous Sn(IV) organophosphonate composite
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A simple, facile and one-pot route for preparing SnO2 nanoclusters embedded on a mesoporous Sn(iv) organophosphonate (MSnP) framework is described. Reaction of SnCl4·5H2O with a flexible tris-phosphonic acid, mesityl-1,3,5-tris(methylenephosphonic acid), in the presence of a surfactant under hydrothermal conditions produced the desired nanocomposite, SnO2@MSnP. Analytical, spectroscopic and microscopic studies establish that SnO2@MSnP composite is comprised of SnO2 nanoparticles of an average size of 5 nm evenly and abundantly dispersed over the MSnP framework. The mesoporous metal organophosphonate support significantly augments the catalytic efficacy and vapor sensitivity of SnO2 nanoparticles. The catalytic efficiency of SnO2@MSnP was tested for two acid-catalyzed reactions: deoximation reaction and esterification of fatty acids. SnO2@MSnP exhibits remarkable sensitivity towards ammonia and acetone vapors at near room temperature and under open atmospheric conditions. The present method represents an important step towards preparation of mesoporous metal organophosphonate supported metal oxide nanoclusters and hence offers easy access to functional metal oxide based nanocomposites.
- Borah, Suchibrata,Bhattacharyya, Bagmita,Deka, Jumi,Borah, Aditya,Devi, Anuchaya,Deka, Dhanapati,Mishra, Shashank,Raidongia, Kalyan,Gogoi, Nayanmoni
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supporting information
p. 8664 - 8672
(2017/07/12)
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