cas 937-30-4, 4-Ethylacetophenone | Articles data

Articles about 937-30-4Total 82 be found

Article title
Article abstract
Author
Journal number and time
Download

Visible light-mediated, high-efficiency oxidation of benzyl to acetophenone catalyzed by fluorescein
An environmentally friendly aerobic oxidation of benzyl C(sp3)-H bonds to ketones via selective oxidation catalysis was developed. Fluorescein is an efficient photocatalyst with excellent chemical selectivity. The reaction has a wide substrate scope, and a successful gram-scale experiment demonstrated its potential industrial utility.
Geng, Haoxing,Liu, Xin,Zhu, Qing
supporting information

(2021/12/20)

Selective Activation of Unstrained C(O)-C Bond in Ketone Suzuki-Miyaura Coupling Reaction Enabled by Hydride-Transfer Strategy
A Rh(I)-catalyzed ketone Suzuki-Miyaura coupling reaction of benzylacetone with arylboronic acid is developed. Selective C(O)-C bond activation, which employs aminopyridine as a temporary directing group and ethyl vinyl ketone as a hydride acceptor, occurs on the alkyl chain containing a β-position hydrogen. A series of acetophenone products were obtained in yields up to 75%.
Zhong, Jing,Zhou, Wuxin,Yan, Xufei,Xia, Ying,Xiang, Haifeng,Zhou, Xiangge
supporting information
p. 1372 - 1377
(2022/02/23)

Selective electrochemical oxidation of aromatic hydrocarbons and preparation of mono/multi-carbonyl compounds
A selective electrochemical oxidation was developed under mild condition. Various mono-carbonyl and multi-carbonyl compounds can be prepared from different aromatic hydrocarbons with moderate to excellent yield and selectivity by virtue of this electrochemical oxidation. The produced carbonyl compounds can be further transformed into α-ketoamides, homoallylic alcohols and oximes in a one-pot reaction. In particular, a series of α-ketoamides were prepared in a one-pot continuous electrolysis. Mechanistic studies showed that 2,2,2-trifluoroethan-1-ol (TFE) can interact with catalyst species and generate the corresponding hydrogen-bonding complex to enhance the electrochemical oxidation performance. [Figure not available: see fulltext.]
Li, Zhibin,Zhang, Yan,Li, Kuiliang,Zhou, Zhenghong,Zha, Zhenggen,Wang, Zhiyong
p. 2134 - 2141
(2021/09/29)

Selective Electrochemical Oxygenation of Alkylarenes to Carbonyls
An efficient electrochemical method for benzylic C(sp3)-H bond oxidation has been developed. A variety of methylarenes, methylheteroarenes, and benzylic (hetero)methylenes could be converted into the desired aryl aldehydes and aryl ketones in moderate to excellent yields in an undivided cell, using O2 as the oxygen source and lutidinium perchlorate as an electrolyte. On the basis of cyclic voltammetry studies, 18O labeling experiments, and radical trapping experiments, a possible single-electron transfer mechanism has been proposed for the electrooxidation reaction.
Li, Xue,Bai, Fang,Liu, Chaogan,Ma, Xiaowei,Gu, Chengzhi,Dai, Bin
supporting information
p. 7445 - 7449
(2021/10/02)

An efficient and practical aerobic oxidation of benzylic methylenes by recyclable: N -hydroxyimide
An efficient and practical benzylic aerobic oxidation catalyzed by cheap and simple N-hydroxyimide organocatalyst has been achieved with high yields and broad substrate scope. The organocatalyst used can be recycled and reused by simple workup and only minute amount (1 mol% in most cases) of simple iron salt is used as promoter. Phenyl substrates with mild and strong electron-withdrawing group could also be oxygenated in high yields as well as other benzylic methylenes. Influence of substituents, gram-scale application, catalysts decay and general mechanism of this methodology has also been discussed. This journal is
Wang, Jian,Zhang, Cheng,Ye, Xiao-Qing,Du, Wenting,Zeng, Shenxin,Xu, Jian-Hong,Yin, Hong
p. 3003 - 3011
(2021/01/28)

Site-Specific Oxidation of (sp3)C-C(sp3)/H Bonds by NaNO2/HCl
A site-specific oxidation of (sp3)C-C(sp3) and (sp3)C-H bonds in aryl alkanes by the use of NaNO2/HCl was explored. The method is chemical-oxidant-free, transition-metal-free, uses water as the solvent, and proceeds under mild conditions, making it valuable and attractive to synthetic organic chemistry.
Zhao, Jianyou,Shen, Tong,Sun, Zhihui,Wang, Nengyong,Yang, Le,Wu, Jintao,You, Huichao,Liu, Zhong-Quan
p. 4057 - 4061
(2021/05/26)

Decatungstate-mediated solar photooxidative cleavage of CC bonds using air as an oxidant in water
With the increasing attention for green chemistry and sustainable development, there has been much interest in searching for greener methods and sources in organic synthesis. However, toxic additives or solvents are inevitably involved in most organic transformations. Herein, we first report the combination of direct utilization of solar energy, air as the oxidant and water as the solvent for the selective cleavage of CC double bonds in aryl olefins. Various α-methyl styrenes, diaryl alkenes as well as terminal styrenes are well tolerated in this green and sustainable strategy and furnished the desired carbonyl products in satisfactory yields. Like heterogeneous catalysis, this homogeneous catalytic system could also be reused and it retains good activity even after repeating three times. Mechanism investigations indicated that both O2- and 1O2 were involved in the reaction. Based on these results, two possible mechanisms, including the electron transfer pathway and the energy transfer pathway, were proposed.
Du, Dongdong,Luo, Junfei,Shi, Sanshan,Xie, Pan,Xue, Cheng
p. 5936 - 5943
(2021/08/23)

Hydration of Alkynes to Ketones with an Efficient and Practical Polyoxomolybdate-based Cobalt Catalyst
Hydration of alkynes to ketones is one of the most atom economical and universal methods for the synthesis of carbonyl compounds. However, the basic reaction usually requires organic ligand catalysts or harsh reaction conditions to insert oxygen into the C≡C bond. Here, we report an inorganic ligand supported cobalt (III) catalyst, (NH4)3[CoMo6O18(OH)6], which is supported by a central cobalt (III) mononucleus and a ring-shaped pure inorganic ligand composed of six MoVIO6 octahedrons to avoid the disadvantages of expensive and unrecyclable organic ligand catalysts or noble metal catalysts. Under mild conditions, the cobalt (III) catalyst can be used for the hydration of alkynes to ketones. The catalyst is non-toxic, green, and environment friendly. The catalyst can be recycled at least six times with high activity. According to control experiments, a reasonable mechanism is provided.
Xie, Ya,Wang, Jingjing,Wang, Yunyun,Han, Sheng,Yu, Han
p. 4985 - 4989
(2021/10/12)

Bismuth subnitrate-catalyzed markovnikov-type alkyne hydrations under batch and continuous flow conditions
Bismuth subnitrate is reported herein as a simple and efficient catalyst for the atom-economical synthesis of methyl ketones via Markovnikov-type alkyne hydration. Besides an effective batch process under reasonably mild conditions, a chemically intensified continuous flow protocol was also developed in a packed-bed system. The applicability of the methodologies was demonstrated through hydration of a diverse set of terminal acetylenes. By simply switching the reaction medium from methanol to methanol-d4, valuable trideuteromethyl ketones were also prepared. Due to the ready availability and nontoxicity of the heterogeneous catalyst, which eliminated the need for any special additives and/or harmful reagents, the presented processes display significant advances in terms of practicality and sustainability.
?tv?s, Sándor B.,Fül?p, Ferenc,Szécsényi, Zsanett
(2021/05/31)

One-Pot Chemoenzymatic Conversion of Alkynes to Chiral Amines
A one-pot chemoenzymatic sequential cascade for the synthesis of chiral amines from alkynes was developed. In this integrated approach, just ppm amounts of gold catalysts enabled the conversion of alkynes to ketones (>99%) after which a transaminase was used to catalyze the production of biologically valuable chiral amines in a good yield (up to 99%) and enantiomeric excess (>99%). A preparative scale synthesis of (S)-methylbenzylamine and (S)-4-methoxy-methylbenzylamine from its alkyne form gave a yield of 59 and 92%, respectively, withee> 99%.
Mathew, Sam,Renn, Dominik,Rueping, Magnus,Sagadevan, Arunachalam
p. 12565 - 12569
(2021/10/21)

Synthesis method of aromatic benzyl ketone
The invention discloses a synthesis method of aromatic benzyl ketone, which comprises the following step: by using oxygen and/or air as an oxidant, oxidizing an aromatic benzyl compound shown in a formula (I) under the action of a catalytic system to obtain aromatic benzyl ketone shown in a formula (II). The catalytic system is formed by combining ferric ions, nitrate radicals and N-hydroxyimide derivatives and does not contain heavy metal ions harmful to human bodies, wherein the molar ratio of the ferric ions to the nitrate radicals is 1: (0.5-5), and the molar ratio of the ferric ions to the N-hydroxyimide derivatives is (0.01-0.1): (0.03-0.2). The method disclosed by the invention is wide in substrate applicability and high in atom utilization rate, avoids the use of harmful heavy metals such as copper and cobalt, and has the characteristics of high efficiency, economy and environmental protection. The formulas are as follows: Ar-CH2-R (I) and Ar-CO-R (II).
-
Paragraph 0068-0073

(2020/09/12)

Method for synthesizing aromatic ketone by catalytic oxidation of aromatic benzylic secondary C-H bonds through metalloporphyrin (by machine translation)
A method for synthesizing aromatic ketone by catalytic oxidation of aromatic benzylic secondary C-H bonds through metalloporphyrin, the method comprising: (1 ×10) preparing metalloporphyrin-4 % - 1%, Mol / mol are dispersed in the aromatic hydrocarbon, the reaction system is sealed, the temperature is raised to 80 - 150 °C by stirring, the oxidant is introduced to 0.20 - 2.0 mpa, the set temperature and pressure are maintained, ?datdatdate? is stirred 3.0-24 . 0h, and the reaction liquid is subjected to post-treatment to obtain the product aromatic ketone compound. The method has the advantages of low reaction temperature, low catalyst consumption, high selectivity of the aromatic ketone compound, low peroxide content and high production safety factor, and has the potential of overcoming the defects of high reaction temperature, low corrosive solvent and auxiliary agent in the catalytic oxidation process of the aromatic benzylic secondary C-H bonds in the industry. The method is efficient, feasible and safe. (by machine translation)
-
Paragraph 0082-0083

(2020/09/20)

1,2-Diethoxyethane catalyzed oxidative cleavage of gem-disubstituted aromatic alkenes to ketones under minimal solvent conditions
Aerobic oxidation using pure dioxygen gas as the oxidant has attracted much attention, but its application in synthetic chemistry has been significantly hampered by the complexity of catalytic system and potential risk of high-energy dioxygen gas. By employing 1,2-diethoxyethane as a catalyst and ambient air as an oxidant, an efficient protocol for the construction of various aryl-alkyl and diaryl ketones through oxidative cleavage of gem-disubstituted aromatic alkenes under minimal solvent conditions has been achieved.
Liu, Kai-Jian,Deng, Ji-Hui,Zeng, Tang-Yu,Chen, Xin-Jie,Huang, Ying,Cao, Zhong,Lin, Ying-Wu,He, Wei-Min
supporting information
p. 1868 - 1872
(2020/01/31)

Synthesis and Catalytic Properties of Metal- N-Heterocyclic-Carbene-Decorated Covalent Organic Framework
We demonstrate herein that the N-heterocyclic-carbene (NHC)-metal complex (NHC-M)-involved covalent organic framework (COF) can be prepared by the direct polymerization of the NHC-M monomer with its counterpart under solvothermal conditions. The NHC-M-COF with different counterions is readily achieved via solid-state anion exchange. The obtained NHC-AuX-COF (X = Cl- and SbF6-) can be a highly active reusable catalyst to separately promote the carboxylation of the terminal alkyne with CO2 and alkyne hydration under mild conditions.
Dong, Ying,Dong, Yu-Bin,Kan, Jing-Lan,Li, Yue,Wu, Xiaowei
supporting information
p. 7363 - 7368
(2020/10/12)

Iron-catalyzed oxidative functionalization of C(sp3)-H bonds under bromide-synergized mild conditions
An efficient oxidation and functionalization of C-H bonds with an inorganic-ligand supported iron catalyst and hydrogen peroxide to prepare the corresponding ketones was achieved using the bromide ion as a promoter. Preliminary mechanistic investigations indicated that the bromide ion can bind to FeMo6 to form a supramolecular species (FeMo6·2Br), which can effectively catalyze the reaction.
Yu, Han,Zhao, Qixin,Wei, Zheyu,Wu, Zhikang,Li, Qi,Han, Sheng,Wei, Yongge
supporting information
p. 7840 - 7843
(2019/07/12)

Photoredox-Catalysis-Modulated, Nickel-Catalyzed Divergent Difunctionalization of Ethylene
Divergent synthesis that enables a catalytic reaction to selectively produce different products from common substrates will allow the charting of wider chemical space and the unveiling of distinct mechanistic paradigms. A common strategy for it employs different ligands to modulate organometallic catalysts. Dramatic developments in photocatalysis have enabled previously inaccessible transformations. In particular, photoredox catalysis modulates the oxidation state of transition-metal complexes, offering enormous opportunities for methodology development. Herein, we developed a photo-mediated divergent ethylene difunctionalization via modulating oxidation states of the nickel catalyst by using different photoredox catalysts. This work will inspire new perspectives for value-added chemical synthesis using ethylene as a feedstock and shed light on photoredox-catalyst-based divergent synthesis, which fundamentally differs from ligand-controlled transition-metal catalysis.Divergent synthesis represents a powerful strategy for directly accessing different molecular scaffolds originating from the same starting materials. Access to different end products via transition-metal catalysis is conventionally achieved by ligand control. We herein demonstrate the use of ethylene feedstock and commercially available aryl halides to accomplish the divergent synthesis of 1,2-diarylethanes, 1,4-diarylbutanes, or 2,3-diarylbutanes in a highly selective fashion through the synergistic combination of nickel and photoredox catalysis. Mechanistic studies suggest that the observed selectivity was due to different active states of Ni(I) and Ni(0) modulated by Ru- and Ir-based photoredox catalysts, respectively. The ability to access different organometallic oxidation states via photoredox catalysis promises to inspire new perspectives for synergistic transition-metal-catalyzed divergent synthesis.Functionalization of ethylene without polymerization is challenging under photo-irradiation conditions. We have demonstrated that the photo-transformation of ethylene can be controllable by merging photoredox and transition-metal catalysis. In our study, the use of different photoredox catalysts was able to modulate the oxidation state of the nickel catalyst. Through different oxidation states, the nickel-catalyzed couplings proceeded via distinct pathways to generate divergent ethylene difunctionalization products selectively from the same feedstock.
Li, Jiesheng,Luo, Yixin,Cheo, Han Wen,Lan, Yu,Wu, Jie
supporting information
p. 192 - 203
(2019/01/21)

Iridium-Catalyzed Alkene-Selective Transfer Hydrogenation with 1,4-Dioxane as Hydrogen Donor
The iridium-catalyzed transfer hydrogenation of alkenes using 1,4-dioxane as a hydrogen donor is described. The use of 1,2-bis(dicyclohexylphosphino)ethane (DCyPE), featuring bulky and highly electron-donating properties, led to high catalytic activity. A polystyrene-cross-linking bisphosphine PS-DPPBz produced a reusable heterogeneous catalyst. These homogeneous and heterogeneous protocols achieved chemoselective transfer hydrogenation of alkenes over other potentially reducible functional groups such as carbonyl, nitro, cyano, and imino groups in the same molecule.
Zhang, Deliang,Iwai, Tomohiro,Sawamura, Masaya
supporting information
p. 5867 - 5872
(2019/08/26)

Efficient Palladium(0) supported on reduced graphene oxide for selective oxidation of olefins using graphene oxide as a ‘solid weak acid’
Selective oxidation of olefin derivatives to ketones has made innovative development over palladium(0) supported on reduced graphene oxide. Compared to traditional Wacker oxidation, the novel method offers an economical and environment-friendly option by using graphene oxide (GO) as a ‘solid weak acid’ instead of classical homogeneous catalysts like H2SO4 and CF3COOH. X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy images of Pd0/RGO showed that the nanoscaled Pd particles generated at the flake structure of reduced graphene oxide. Under optimized condition, up to 44 kinds of ketones with different structures can be prepared with excellent yields.
Gao, Xi,Zhou, Jianhao,Peng, Xinhua
p. 73 - 78
(2019/02/06)

Selective Semi-Hydrogenation of Terminal Alkynes Promoted by Bimetallic Cu-Pd Nanoparticles
The selective semi-hydrogenation of terminal alkynes was efficiently performed, under mild reaction conditions (H 2 balloon, 110 °C), promoted by a bimetallic nanocatalyst composed of copper and palladium nanoparticles (5:1 weight ratio) supported on mesostructured silica (MCM-48). The Cu-PdNPS@MCM-48 catalyst, which demonstrated to be highly chemoselective towards the alkyne functionality, is readily prepared from commercial materials and can be recovered and reused after thermal treatment followed by reduction under H 2 atmosphere.
Buxaderas, Eduardo,Volpe, María Alicia,Radivoy, Gabriel
p. 1466 - 1472
(2019/03/07)

The synthesis of methyl triazole-4-carboxylate gold(I) complex and application on allene synthesis and alkyne hydration
The methyl 1H-1,2,3-triazole-4-carboxylate containing a strong electron-withdrawing group was developed and applied as a ligand for gold(I) cations. The resulting ester-triazole gold(I) complex was investigated for its efficiency in catalyzing allene synthesis and alkyne hydration, in which an excellent catalytic efficiency was observed with low catalyst loadings.
Hu, Wenkang,Shan, Liang,Ma, Fudong,Zhang, Yilin,Yang, Yongchun,Wang, Dawei
(2019/10/14)

Synthesis method of primary amine hydrochloride
The invention discloses a synthesis method of primary amine hydrochloride. According to the synthesis method, in the presence of a gold complex, water and alkyne carry out catalytic hydrolysis to generate ketones, and then ketones and ammonium formate are catalyzed by a rhodium complex to generate primary amine. Compared with a conventional primary amine synthesis method, the synthesis method hasthe advantages that no alkali is added during the reaction process, no side product is generated, the atomic economy is good, the reaction conditions are mild, and the synthesis method has a wide prospect.
-
Paragraph 0050-0052

(2019/03/09)

Transfer Hydrogenation of Alkenes Using Ethanol Catalyzed by a NCP Pincer Iridium Complex: Scope and Mechanism
The first general catalytic approach to effecting transfer hydrogenation (TH) of unactivated alkenes using ethanol as the hydrogen source is described. A new NCP-type pincer iridium complex (BQ-NCOP)IrHCl containing a rigid benzoquinoline backbone has been developed for efficient, mild TH of unactivated C-C multiple bonds with ethanol, forming ethyl acetate as the sole byproduct. A wide variety of alkenes, including multisubstituted alkyl alkenes, aryl alkenes, and heteroatom-substituted alkenes, as well as O- or N-containing heteroarenes and internal alkynes, are suitable substrates. Importantly, the (BQ-NCOP)Ir/EtOH system exhibits high chemoselectivity for alkene hydrogenation in the presence of reactive functional groups, such as ketones and carboxylic acids. Furthermore, the reaction with C2D5OD provides a convenient route to deuterium-labeled compounds. Detailed kinetic and mechanistic studies have revealed that monosubstituted alkenes (e.g., 1-octene, styrene) and multisubstituted alkenes (e.g., cyclooctene (COE)) exhibit fundamental mechanistic difference. The OH group of ethanol displays a normal kinetic isotope effect (KIE) in the reaction of styrene, but a substantial inverse KIE in the case of COE. The catalysis of styrene or 1-octene with relatively strong binding affinity to the Ir(I) center has (BQ-NCOP)IrI(alkene) adduct as an off-cycle catalyst resting state, and the rate law shows a positive order in EtOH, inverse first-order in styrene, and first-order in the catalyst. In contrast, the catalysis of COE has an off-cycle catalyst resting state of (BQ-NCOP)IrIII(H)[O(Et)···HO(Et)···HOEt] that features a six-membered iridacycle consisting of two hydrogen-bonds between one EtO ligand and two EtOH molecules, one of which is coordinated to the Ir(III) center. The rate law shows a negative order in EtOH, zeroth-order in COE, and first-order in the catalyst. The observed inverse KIE corresponds to an inverse equilibrium isotope effect for the pre-equilibrium formation of (BQ-NCOP)IrIII(H)(OEt) from the catalyst resting state via ethanol dissociation. Regardless of the substrate, ethanol dehydrogenation is the slow segment of the catalytic cycle, while alkene hydrogenation occurs readily following the rate-determining step, that is, β-hydride elimination of (BQ-NCOP)Ir(H)(OEt) to form (BQ-NCOP)Ir(H)2 and acetaldehyde. The latter is effectively converted to innocent ethyl acetate under the catalytic conditions, thus avoiding the catalyst poisoning via iridium-mediated decarbonylation of acetaldehyde.
Wang, Yulei,Huang, Zhidao,Leng, Xuebing,Zhu, Huping,Liu, Guixia,Huang, Zheng
supporting information
p. 4417 - 4429
(2018/04/05)

Nickel-Catalyzed Addition of Arylboronic Acids to Alkyl Nitriles for Synthesis of Aryl Ketones in Fluorinated Solvent
A mild and efficient nickel-catalyzed addition of arylboronic acids to alkyl nitriles in a fluorinated solvent for the synthesis of various aryl ketones is described. A broad range of arylboronic acids and alkyl nitriles were investigated, and the desired products were obtained with good to excellent yields under the optimized conditions. This method provides an opportunity for the synthesis of aryl ketones from alkyl nitriles, especially acetonitrile, with a non-noble metal catalyst in one pot.
Tu, Dong-Huai,Li, Yang,Zhao, Bo,Gu, Yu-Jie,Wang, Bo,Lu, Ju-You,Lu, Jian
supporting information
p. 593 - 596
(2017/12/06)

Metal/catalyst/reagent free hydration of alkynes up to gram scale under temperature and pressure controlled condition
A new green water-mediated metal/catalyst/reagent-free methodology for hydration of alkyne is devised. The remarkable yields of various ketones were achieved when alkynes were heated at 150 °C under 11 bar pressure in an autoclave for 14 h in water-methanol solution. Outstanding functional group compatibility for both the terminal and internal alkynes was established. This methodology produces excellent yields up to gram scale under optimised reaction condition.
Ali, Munsaf,Srivastava, Avinash K.,Joshi, Raj K.
p. 2075 - 2078
(2018/05/04)

Photo induced alkyne hydration reactions mediated by a water soluble, reusable Rhodium (I) catalyst
Under photochemical irradiation, the hydration of aryl alkynes in the presence of water proceeds in good yields to afford the corresponding ketone, using a water-soluble rhodium (I) catalyst. The catalyst is effective for internal and terminal alkynes and showed high functional group compatibility. A low catalyst loading, low temperature and shorter duration of photolysis are ideal feature of reaction. The catalyst can be reused several times under aerobic and aqueous conditions, exemplifying the robust nature of the catalyst. In comparison with known Rh and other metal catalysts, the present reaction provides a remarkable green approach for alkyne hydration reactions.
Ali, Munsaf,Srivastava, Avinash K.,Siangwata, Shepherd,Smith, Gregory S.,Joshi, Raj K.
p. 78 - 81
(2018/07/29)

Transformation of Alkynes into Chiral Alcohols via TfOH-Catalyzed Hydration and Ru-Catalyzed Tandem Asymmetric Hydrogenation
A novel full atom-economic process for the transformation of alkynes into chiral alcohols by TfOH-catalyzed hydration coupled with Ru-catalyzed tandem asymmetric hydrogenation in TFE under simple conditions has been developed. A range of chiral alcohols was obtained with broad functional group tolerance, good yields, and excellent stereoselectivities.
Liu, Sensheng,Liu, Huan,Zhou, Haifeng,Liu, Qixing,Lv, Jinliang
supporting information
p. 1110 - 1113
(2018/02/23)

One-pot synthesis of chiral alcohols from alkynes by CF3SO3H/ruthenium tandem catalysis
A practical one-pot synthesis of chiral alcohols from readily available alkynes via tandem catalysis by the combination of CF3SO3H and a fluorinated chiral diamine Ru(ii) complex in aqueous CF3CH2OH is described. Very interestingly, the combination of fluorinated catalysts and solvent exhibits a positive fluorine effect on the reactivity and enantioselectivity. A range of chiral alcohols with wide functional group tolerance was obtained in high yield and excellent stereoselectivity under simple and mild conditions.
Liu, Huan,Liu, Sensheng,Zhou, Haifeng,Liu, Qixing,Wang, Chunqin
p. 14829 - 14832
(2018/04/30)

Secondary amine compound synthesized from alkyne and synthesis method of secondary amine compound
The invention relates to a secondary amine compound synthesized from alkyne and a synthesis method of the secondary amine compound. The specific structure of the compound is shown as the formula II inthe description. Meanwhile, the invention discloses the three-step one-pot synthesis method of the compound. According to the method, cheap and available acetenyl substituted benzene (I) is taken asa raw material. The method comprises steps as follows: step 1), fluorine-containing alcohol and water are taken as solvents and subjected to a hydration reaction under catalysis of trifluoromethanesulfonic acid, and an intermediate ketone is generated; step 2), aromatic amines are added directly to a reaction system, and imine is generated; step 3), tetrahydroxydiboron is added to the system, anda product II is obtained. No metal participates in the method, operation is simple and convenient, the raw materials are easily available, reaction conditions are mild, and yield is relatively high.
-
Paragraph 0046; 0047; 0048

(2018/10/19)

An efficient approach for enhancing the catalytic activity of Ni-MOF-74: Via a relay catalyst system for the selective oxidation of benzylic C-H bonds under mild conditions
Although nickel-based materials exhibit similar catalytic activity to palladium in organic synthesis, the selective oxidation of inert C-H bonds in the absence of other co-catalysts remains a largely unsolved challenge. This paper introduces a facile and efficient approach for enhancing the catalytic activity of Ni-MOF-74 with [bmim]Br via a relay catalysis strategy, which is excellent for the selective oxidation of benzylic C-H bonds. Notably, the catalyst recycling and scale up experiments demonstrated the practicability of the protocol. This method combines the catalytic advantages of MOFs and ionic liquids (ILs), and provides an insight into oxidation reactions by cheap and efficient Ni-based catalysts.
Guo, Changyan,Zhang, Yonghong,Zhang, Yi,Wang, Jide
supporting information
p. 3701 - 3704
(2018/04/17)

Method for directly oxidizing benzyl-position C-H bond into ketone
The invention discloses a method for directly oxidizing a benzyl-position C-H bond into ketone, wherein aryl ethyl compounds are catalyzed and oxidized by nitrite ester; a synergistic catalytic system of free radical initiator and nitrite ester is adopted, and a catalytic system of non-metallic catalyst and oxygen is adopted, the oxidization of the C-H bond of a free radical-activated aryl side chain is simple in operation; after completing the reaction, petroleum ether/ethyl acetate at a volume ratio of (50-1):1 is used as an eluent; column chromatography separation is performed to obtain a target product. The catalytic system in the invention uses oxygen as an oxygen source and has high atomic economy; the invention is a non-metallic catalytic system and provides a novel method for avoid metal residues in synthetic drugs; for diethyl aromatic hydrocarbon, the method provided by the invention can be adopted to selectively oxidize diethyl aromatic hydrocarbon into monoketone and diketone; the method of the invention can be adopted to efficiently synthesize tranquillizer lenperone, so that a novel method for synthesizing lenperone is provided.
-
Paragraph 0078-0081

(2017/08/29)

Organopromoted Selectivity-Switchable Synthesis of Polyketones
In this work, an organopromoted metal-free pharmaceutical-oriented selectivity-switchable benzylic oxidation was developed, affording mono-, di-, and trioxygenation products, respectively, using oxygen as the oxidant under mild conditions. This process facilitates dioxygenation of 2,6-benzylic positions of heterocycles, which could be inhibited by heterocycle chelation to the metal cocatalysts. Enantiopure chiral ketones could also be prepared. The noninvolvement of transition metals and toxins avoids metal or hazardous residues, consequently ensuring a final-stage gram-scale synthesis of Lenperone.
Liu, Jie,Hu, Kang-Fei,Qu, Jian-Ping,Kang, Yan-Biao
supporting information
p. 5593 - 5596
(2017/10/25)

Synergetic oxidation of ethylbenzene to acetophenone catalyzed by manganese(II) complexes bearing pendant iodophenyl groups
Five tetradentate ligands, L1–5, bearing the moiety of bis(pyridin-2-ylmethyl)amine (1) and their complexes with Mn(II) were prepared. All the compounds and metal complexes were appropriately characterized. The five manganese(II) complexes (3a–e) are of the formula, [Mn(II)LxCl2] (x = 1-5), as suggested by the crystal structure of complexes 3b and 3c. All the ligands except for L3 possess two iodobenzene groups via an ether linkage (except for L1) with various lengths. By using oxone as an oxidant, the catalytic activity of these complexes on the oxidation of ethylbenzene to acetophenone in acetonitrile/water at room temperature was studied. Our results showed that the pendant iodophenyl groups play a synergetic role with the metal center in the catalysis, and complex 3b possesses the most appropriate length of the linkage between the iodobenzene group and the metal center. EPR and FTIR data suggest that the metal center of the active species should be Mn(IV) after the oxidation of oxone under the reaction conditions. A catalytic mechanism was also proposed based on the experimental observations.
Yang, Yiwen,Zhong, Wei,Nie, Binmei,Chen, Jiangmin,Wei, Zhenhong,Liu, Xiaoming
supporting information
p. 136 - 142
(2017/11/10)

Selective Oxidation of Styrene Derivatives to Ketones over Palladium(0)/Carbon with Hydrogen Peroxide as the Sole Oxidant
Pd0/C catalyst exhibited excellent catalytic activity in the Wacker oxidation of styrene derivatives to corresponding ketones with hydrogen peroxide as a clean oxidant. Compared with the conventional Wacker system, the newly developed method offers a cost-efficient and environmentally friendly option without the use of a copper salt as a co-catalyst.
Xia, Xiaomeng,Gao, Xi,Xu, Junhui,Hu, Chuanfeng,Peng, Xinhua
supporting information
p. 607 - 610
(2017/03/11)

The facile approach to fabricate gold nanoparticles and their application on the hydration and dehydrogenation reactions
A mild and practical strategy to prepare gold nanoparticles was developed. This gold particles supported mesoporous silica was fabricated from AuPPh3Cl under mild conditions and characterized through transmission electron microscopy, energy dispersive X-ray, X-ray power diffraction and X-ray photoelectron spectrometry. Interestingly, it was observed that this gold nanoparticle was effective to the hydration of alkynes and dehydrogenation of alcohols. The catalytic system can tolerate a variety of functional groups to afford the corresponding products in good to excellent yields.
Huang, Ronghui,Fu, Yong,Zeng, Wei,Zhang, Liang,Wang, Dawei
p. 46 - 51
(2017/09/18)

Visible light promoted copper-catalyzed Markovnikov hydration of alkynes at room temperature
A new and efficient method for the hydration of alkynes to the corresponding ketones was successfully developed. The hydration process proceeds smoothly at room temperature with 1% mol of CuCl as catalyst under visible light irradiation. This protocol is applicable to various alkynes, including aromatic alkynes, polycyclic aromatic and heterocyclic aromatic excellent regioselectivity in good to excellent yields.
Niu, Teng-fei,Jiang, Ding-yun,Li, Si-yuan,Shu, Xing-ge,Li, Huan,Zhang, Ai-ling,Xu, Jia-yu,Ni, Bang-qing
supporting information
p. 1156 - 1159
(2017/03/02)

Room-temperature direct benzylic oxidation catalyzed by cobalt(II) perchlorate
Aromatic ketones were synthesized from alkylbenzene derivatives through a novel method that employs cobalt(II) perchlorate as catalyst and oxone as oxidant. The reaction smoothly proceeded at room temperature with yields reaching 96%.
Yang, Yiwen,Ma, Hongxia
supporting information
p. 5278 - 5280
(2016/11/09)

One pot synthesis of α-ketoamides from ethylarenes and amines: a metal free difunctionalization strategy
One-pot and metal free synthesis of α-ketoamides has been described through in situ generation of aryl ketones from easily available ethylarenes followed by amidation with various amines. This multiple oxidation protocol involves catalytic I2-pyridine-TBHP (t-butyl hydroperoxide) mediated oxidative benzylic carbonylation and sequential NaI-TBHP mediated oxidative amidation without using any solvent.
Ramanathan, Mani,Kuo, Chun-Kai,Liu, Shiuh-Tzung
p. 11446 - 11453
(2016/12/16)

Domino Methylenation/Hydrogenation of Aldehydes and Ketones by Combining Matsubara's Reagent and Wilkinson's Catalyst
The methylenation/hydrogenation cascade reaction of aldehydes or ketones through a domino process involving two ensuing steps in a single pot is realized. The compatibility of Matsubara's reagent and Wilkinson's complex give a combination that allows, under dihydrogen, the transformation of a carbonyl function into a methyl group. This new method is suitable to introduce an ethyl motif from aromatic and aliphatic aldehydes with total chemoselectivity and total retention of α-stereochemical purity. The developed procedure is also extended to the introduction of methyl groups from ketones.
Maazaoui, Radhouan,Pin-Nó, María,Gervais, Kevin,Abderrahim, Raoudha,Ferreira, Franck,Perez-Luna, Alejandro,Chemla, Fabrice,Jackowski, Olivier
supporting information
p. 5732 - 5737
(2016/12/14)

Catalyst-free hydrochlorination protocol for terminal arylalkynes with hydrogen chloride
We present a simple and straightforward protocol for hydrochlorination of terminal arylalkynes to vinyl chlorides using hydrogen chloride under mild reaction conditions. This protocol does not involve any metal catalysts or additives. It is simple, inexpensive, and easy to prepare, and exhibits good reaction activity. The hydrochlorination proceeds smoothly to yield unique regioselective products via the Markovnikov addition rule.
Xu, Cai-Xia,Ma, Cun-Hua,Xiao, Fu-Rong,Chen, Hong-Wei,Dai, Bin
supporting information
p. 1683 - 1685
(2016/11/12)

A Pd-Cu2O nanocomposite as an effective synergistic catalyst for selective semi-hydrogenation of the terminal alkynes only
A new type lead-free catalyst of a Pd-Cu2O nanocomposite was developed for highly selective semi-hydrogenation of alkynes. With unprecedented selectivity for the semi-hydrogenation of terminal alkynes to alkenes, we show for the first time that the catalyst only hydrogenated the terminal alkynes, i.e. did not hydrogenate the internal alkynes.
Yang, Shuliang,Cao, Changyan,Peng, Li,Zhang, Jianling,Han, Buxing,Song, Weiguo
supporting information
p. 3627 - 3630
(2016/03/05)

A Combination System of p -Toluenesulfonic Acid and Acetic Acid for the Hydration of Alkynes
A simple combination system of p-toluenesulfonic acid/acetic acid has been developed for efficient hydration of alkynes. The corresponding ketones can be obtained in good to excellent yields under mild conditions. The mechanism of the reaction was disclosed unambiguously which was a stepwise process (addition and then hydrolysis). Furthermore, this system was proved to be powerful that has the potential to be used to synthesize vinyl 4-methylbenzenesulfonates.
Liu, Haixuan,Wei, Yunyang,Cai, Chun
supporting information
p. 2378 - 2383
(2016/09/28)

Ketone synthesis method through alkyne hydrolysis
The invention discloses a ketone synthesis method through alkyne hydrolysis. The method comprises the following steps: adding alkyne, a catalyst [(IPr)AuCl], a solvent methanol, and water into a reactor, carrying out reactions for several hours at a temperature of 110 to 120 DEG C, cooling to the room temperature, carrying out rotary evaporation to remove the solvent, and performing column separation to obtain target compounds. Compared with conventional ionic gold catalyst, the provided method directly uses gold chloride [(IPr)AuCl] as the catalyst, alkyne is hydrolyzed into ketone, the yield is high, the selectivity is complete, and thus the method has an important meaning for organic synthesis and environment protection.
-
Paragraph 0033-0036

(2017/05/02)

An environmentally benign hydration of alkynes catalyzed by gallic acid/tannic acid in water
A gallic acid catalyzed hydration strategy from alkynes under mild conditions has been developed. The catalyst system exhibits excellent activity, thus avoiding the use of any transition metal, strong acids or other toxic reagent as cocatalysts. Recycling experiments were conducted, and this procedure can be scaled up. Other tannins such as tannic acid can also be applied in this reaction which shows the potential utilization of natural feedstocks.
Deng, Tao,Wang, Cheng-Zhang
p. 7029 - 7032
(2016/10/07)

Benzyllithiums bearing aldehyde carbonyl groups. A flash chemistry approach
Reductive lithiation of benzyl halides bearing aldehyde carbonyl groups followed by reaction with subsequently added electrophiles was successfully accomplished without affecting the carbonyl groups by taking advantage of short residence times in flow microreactors.
Nagaki, Aiichiro,Tsuchihashi, Yuta,Haraki, Suguru,Yoshida, Jun-ichi
supporting information
p. 7140 - 7145
(2015/07/01)

Continuous-flow hydrogenation of olefins and nitrobenzenes catalyzed by platinum nanoparticles dispersed in an amphiphilic polymer
A method for the flow hydrogenation of olefins and nitrobenzenes in a continuous-flow reactor containing platinum nanoparticles dispersed on an amphiphilic polystyrene-poly(ethylene glycol) resin (ARP-Pt) was developed. The hydrogenation of olefins and nitrobenzenes was completed within 31 seconds in the continuous-flow system containing ARP-Pt, giving the corresponding hydrogenated products in up to 99% yield with good chemoselectivity. Moreover, long-term (63-70 h) continuous-flow hydrogenation of styrene and nitrobenzene produced more than ten grams of ethylbenzene and aniline, respectively, without significant loss of catalytic activity. The flow hydrogenation system provides an efficient and practical method for the chemoselective reduction of olefins and nitrobenzenes. This journal is
Osako, Takao,Torii, Kaoru,Tazawa, Aya,Uozumi, Yasuhiro
p. 45760 - 45766
(2015/06/08)

5-Aryl-1H-pyrazole-3-carboxylic acids as selective inhibitors of human carbonic anhydrases IX and XII
Inhibitory activity of a congeneric set of 23 phenyl-substituted 5-phenyl-pyrazole-3-carboxylic acids toward human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms I, II, IX and XII was evaluated by a stopped-flow CO2 hydrase assay. These compounds exerted a clear, selective inhibition of hCA IX and XII over hCAI and II, with Ki in two to one digit micromolar concentrations (4-50 μM). Derivatives bearing bulkier substituents in para-position of the phenyl ring inhibited hCA XII at one-digit micromolar concentrations, while derivatives having alkyl substituents in both ortho- and meta-positions inhibited hCA IX with Kis ranging between 5 and 25 μM. Results of docking experiments offered a rational explanation on the selectivity of these compounds toward CA IX and XII, as well as on the substitution patterns leading to best CA IX or CA XII inhibitors. By examining the active sites of these four isoforms with GRID generated molecular-interaction fields, striking differences between hCA XII and the other three isoforms were observed. The field of hydrophobic probe (DRY) appeared significantly different in CA XII active site, comparing to other three isoforms studied. To the best of our knowledge such an observation was not reported in literature so far. Considering the selectivity of these carboxylates towards membrane-associated over cytosolic CA isoforms, the title compounds could be useful for the development of isoform-specific non-sulfonamide CA inhibitors.
Cvijeti?, Ilija N.,Tan?, Muhammet,Jurani?, Ivan O.,Verbi?, Tatjana ?.,Supuran, Claudiu T.,Drakuli?, Branko J.
p. 4649 - 4659
(2015/08/03)

Synthesis of a-Alkylated Ketones via Tandem Acceptorless Dehydrogenation/a-Alkylation from Secondary and Primary Alcohols Catalyzed by Metal-Ligand Bifunctional Iridium Complex [CpIr(2,2′-bpyO)(H2O)]
A new strategy for the synthesis of α-alkylated ketones via tandem acceptorless dehydrogenation/α-alkylation from secondary and primary alcohols was proposed and accomplished. In the presence of metal-ligand bifunctional iridium complex [CpIr(2,2′-bpyO)(H2O)], various desirable products were obtained in high yields. Compared with previous methods for the direct dehydrogenative coupling of secondary alcohols with primary alcohols to α-alkylated ketones, this protocol has obvious advantages including complete selectivity for α-alkylated ketones and more environmentally benign conditions. Notably, the study also exhibited the potential to develop tandem reactions catalyzed using a metal-ligand bifunctional iridium complex.
Wang, Rongzhou,Ma, Juan,Li, Feng
p. 10769 - 10776
(2015/11/18)

Green photocatalytic organic transformations by polyoxometalates vs. mesoporous TiO2 nanoparticles: Selective aerobic oxidation of alcohols
In this study, the catalytic activity of decatungstate (W10O324-) supported on mesoporous TiO2 nanoparticle assemblies (DT-MTA) was compared with that of homogeneous [Bu4N]4W10O32 catalysts under mild conditions. Our experiments showed that both catalytic systems achieve exceptionally high activity and selectivity under UV-visible light oxidation of various para-substituted aryl alcohols, using molecular oxygen as a "green" oxidant. The chemoselective transformation of aryl alcohols into the corresponding ketones was investigated with gas chromatography (GC) and NMR spectroscopy. Product analysis and kinetic results also indicated that these photooxidation reactions proceed via both electron transfer (ET) and hydrogen atom transfer (HAT) mechanisms over the DT-MTA catalyst, with the former one as the predominant, whereas a HAT route was adopted to account for the decatungstate homogeneous catalyzed reactions. This journal is
Symeonidis, Theodoros S.,Tamiolakis, Ioannis,Armatas, Gerasimos S.,Lykakis, Ioannis N.
p. 563 - 568
(2015/03/14)

Hydration of alkynes at room temperature catalyzed by gold(I) isocyanide compounds
An effective method using gold(I) isocyanide complexes as catalysts for the transformation of various alkynes to the corresponding ketones is successfully developed. The hydration process proceeds smoothly at room temperature with quite high yield (up to 99%). The catalytic center is the isocyanide-Au(I)+ cation. Further theoretical research reveals a direct hydration mechanism by H2O, and the rate-determining step has an energy barrier of 23.7 kcal mol?1. These results show a good example to reduce unnecessary steps and achieve milder reaction conditions at the same time for the hydration of alkynes.
Xu, Yun,Hu, Xingbang,Shao, Jing,Yang, Guoqiang,Wu, Youting,Zhang, Zhibing
supporting information
p. 532 - 537
(2018/04/16)

Regioselective hydration of terminal alkynes catalyzed by a neutral gold(I) complex [(IPr)AuCl] and one-pot synthesis of optically active secondary alcohols from terminal alkynes by the combination of [(IPr)AuCl] and Cp?RhCl[(R, R)-TsDPEN]
A neutral gold(I) complex [(IPr)AuCl] (IPr = 1,3-bis(diisopropylphenyl)imidazol-2-ylidene) was found to be a highly effective catalyst for the hydration of terminal alkynes, including aromatic alkynes and aliphatic alkynes. The desired methyl ketones were obtained in high yields with complete regioselectivities. Furthermore, a series of optically active secondary alcohols could be obtained in high yield with good to excellent enatioselectivities via one-pot sequential hydration/asymmetric transfer hydrogenation (ATH) from terminal alkynes by the combination of of [(IPr)AuCl] and Cp?RhCl[(R,R)-TsDPEN] (Cp? = pentamethylcyclopentadienyl, TsDPEN = N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine). Notably, this research exhibited the potential of the direct use of neutral gold(I) complexes instead of cationic ones as catalysts for the activation of multiple bonds for organic synthesis.
Li, Feng,Wang, Nana,Lu, Lei,Zhu, Guangjun
p. 3538 - 3546
(2015/04/14)