cas 345-92-6, Bis(4-fluorophenyl)-methanone

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Mn(III) active site in hydrotalcite efficiently catalyzes the oxidation of alkylarenes with molecular oxygen
Developing efficient heterogeneous catalytic systems based on easily available materials and molecular oxygen for the selective oxidation of alkylarenes is highly desirable. In the present research, NiMn hydrotalcite (Ni2Mn-LDH) has been found as an efficient catalyst in the oxidation of alkylarenes using molecular oxygen as the sole oxidant without any additive. Impressive catalytic performance, excellent stability and recyclability, broad applicable scope and practical potential for the catalytic system have been observed. Mn3+ species was proposed to be the efficient active site, and Ni2+ played an important role in stabilizing the Mn3+ species in the hydrotalcite structure. The kinetic study showed that the aerobic oxidation of diphenylmethane is a first-order reaction over Ni2Mn-LDH with the activation energy (Ea) and pre-exponential factor (A0) being 85.7 kJ mol?1 and 1.8 × 109 min?1, respectively. The Gibbs free energy (ΔG≠) was determined to be -10.4 kJ mol-1 K-1 for the oxidation based on Eyring-Polanyi equation, indicating the reaction is exergonic. The mechanism study indicated that the reaction proceeded through both radical and carbocation intermediates. The two species were then trapped by molecular oxygen and H2O or hydroxyl species, respectively, to yield the corresponding products. The present research might provide information for constructing highly efficient and stable active site for the catalytic aerobic oxidation based on available and economic material.
Wang, Anwei,Zhou, WeiYou,Sun, Zhonghua,Zhang, Zhong,Zhang, Zhihui,He, MingYang,Chen, Qun
(2020/12/07)

The Origin of Catalytic Benzylic C?H Oxidation over a Redox-Active Metal–Organic Framework
Selective oxidation of benzylic C?H compounds to ketones is important for the production of a wide range of fine chemicals, and is often achieved using toxic or precious metal catalysts. Herein, we report the efficient oxidation of benzylic C?H groups in a broad range of substrates under mild conditions over a robust metal–organic framework material, MFM-170, incorporating redox-active [Cu2II(O2CR)4] paddlewheel nodes. A comprehensive investigation employing electron paramagnetic resonance (EPR) spectroscopy and synchrotron X-ray diffraction has identified the critical role of the paddlewheel moiety in activating the oxidant tBuOOH (tert-butyl hydroperoxide) via partial reduction to [CuIICuI(O2CR)4] species.
Carter, Joseph H.,Day, Sarah J.,Han, Xue,Kang, Xinchen,Kimberley, Louis,Li, Jiangnan,McInnes, Eric J. L.,Schr?der, Martin,Sheveleva, Alena M.,Smith, Gemma L.,Tang, Chiu C.,Tuna, Floriana,Yang, Sihai
supporting information
p. 15243 - 15247
(2021/06/08)

Zwitterion-induced organic-metal hybrid catalysis in aerobic oxidation
In many metal catalyses, the traditional strategy of removing chloride ions is to add silver salts via anion exchange to obtain highly active catalysts. Herein, we reported an alternative strategy of removing chloride anions from ruthenium trichloride using an organic [P+-N-] zwitterionic compound via multiple hydrogen bond interactions. The resultant organic-metal hybrid catalytic system has successfully been applied to the aerobic oxidation of alcohols, tetrahydroquinolines, and indolines under mild conditions. The performance of zwitterion is far superior to that of many other common Lewis bases or Br?nsted bases. Mechanistic studies revealed that the zwitterion triggers the dissociation of chloride from ruthenium trichloride via nonclassical hydrogen bond interaction. Preliminary studies show that the zwitterion is applicable to catalytic transfer semi-hydrogenation.
Hu, Rong-Bin,Lam, Ying-Pong,Ng, Wing-Hin,Wong, Chun-Yuen,Yeung, Ying-Yeung
p. 3498 - 3506
(2021/04/07)

Ruthenium-on-Carbon-Catalyzed Facile Solvent-Free Oxidation of Alcohols: Efficient Progress under Solid-Solid (Liquid)-Gas Conditions
A protocol for the ruthenium-on-carbon (Ru/C)-catalyzed solvent-free oxidation of alcohols, which proceeds efficiently under solid-solid (liquid)-gas conditions, was developed. Various primary and secondary alcohols were transformed to corresponding aldehydes and ketones in moderate to excellent isolated yields by simply stirring in the presence of 10% Ru/C under air or oxygen conditions. The solvent-free oxidation reactions proceeded efficiently regardless of the solid or liquid state of the substrates and reagents and could be applied to gram-scale synthesis without loss of the reaction efficiency. Furthermore, the catalytic activity of Ru/C was maintained after five reuse cycles.
Park, Kwihwan,Jiang, Jing,Yamada, Tsuyoshi,Sajiki, Hironao
p. 1200 - 1205
(2021/12/29)

PhSe(O)OH/NHPI-catalyzed oxidative deoximation reaction using air as oxidant
A novel oxidative deoximation method was developed in this article. Compared with the reported organoselenium-catalyzed oxidative deoximation reaction, this reaction employed N-hydroxyphthalimide (NHPI) as the co-catalyst, so that the oxidative deoximation reaction could utilize air as oxidant in the green DMC solvent under mild reaction conditions. Control experiments and X-ray photoelectron spectroscopy (XPS) analysis results indicated that NHPI was essential for activating the catalytic organoselenium species. It could accelerate the activation of molecular oxygen in air to promote the reaction process. The reaction can avoid metal residues in product and is of potential application values in pharmaceutical industry due to the transition metal-free process.
Shi, Yaocheng,Wang, Feng,Yang, Chenggen,Yu, Lei
(2021/09/06)

4,4 ’ - Difluorobenzophenone and preparation method and application thereof
The 4, 4 ’ difluorobenzophenone and the preparation method thereof comprise: mixing a molecular sieve and hydrogen peroxide and with fluorobenzaldehyde to form a mixed solution, oxidizing fluorobenzaldehyde into p-fluorobenzoic acid, wherein the molecular sieve is a catalyst. Hydrochloric acid and zinc chloride are added to the mixed solution to generate p-fluorobenzoyl chloride under the condition that the molecular sieve is used as a catalyst. Fluorobenzene was added to the mixed solution containing the p-fluorobenzoyl chloride to obtain the 4, 4 ’ - difluorobenzophenone. Thus, the synthetic method has the following advantages: 4, the yield of 4 ’ - difluorobenzophenone is not lower 98%, the purity is not lower than 99.999%, and the purity makes it available for preparation of medical grade polyether ether ketone. Reaction conditions are easy to control, and the risk of explosion is reduced to a certain extent.
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(2021/11/21)

Preparation method 4,4 ' -difluorobenzophenone and intermediate thereof
The invention discloses 4-4' -difluorobenzophenone and a preparation method of an intermediate thereof. The preparation method of 4, 4 '- difluorobenzophenone comprises the following steps: S1: 4 - chlorobenzyl chloride and chlorobenzene react under first catalyst to obtain 4, 4' -dichlorophenylmethane. The first catalyst is Lewis acid and/or a molecular sieve with Lewis acid center. S2: The 4, 4 '-dichlorophenylmethane and oxidant are subjected to an oxidation reaction under the action second catalyst to obtain 4, 4' -dichlorobenzophenone. S3: The 4, 4' -dichlorobenzophenone and the alkali metal fluoride are subjected to a halogenation reaction to obtain the invention. The 4' - difluorobenzophenone and the intermediate thereof disclosed by the invention are high in selectivity, high in yield, low in raw material cost, mild in process condition, high in safety and wide in industrial prospect.
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Paragraph 0068; 0073-0074; 0075; 0080-0081; 0082; ...

(2021/09/01)

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)

Photo-induced oxidative cleavage of C-C double bonds for the synthesis of biaryl methanoneviaCeCl3catalysis
A Ce-catalyzed strategy is developed to produce biaryl methanonesviaphotooxidative cleavage of C-C double bonds at room temperature. This reaction is performed under air and demonstrates high activity as well as functional group tolerance. A synergistic Ce/ROH catalytic mechanism is also proposed based on the experimental observations. This protocol should be the first successful Ce-catalyzed photooxidation reaction of olefins with air as the oxidant, which would provide inspiration for the development of novel Ce-catalyzed photochemical synthesis processes.
Xie, Pan,Xue, Cheng,Du, Dongdong,Shi, SanShan
supporting information
p. 6781 - 6785
(2021/08/20)

Preparation method of benzophenone derivative
The invention provides a preparation method of a benzophenone derivative. The preparation method comprises the following step: subjecting a benzoic acid compound as shown in a formula I, a trichlorotoluene compound as shown in a formula II and a benzene compound as shown in a formula III to reacting under the catalysis of Fe2O3 to obtain the benzophenone derivative. According to the preparation method provided by the invention, the metal oxide Fe2O3 with higher stability and safety is used as a catalyst, so corrosion of materials to equipment is avoided, and the preparation method is more environment-friendly; according to the preparation method, the target product is obtained through one-step reaction, reaction conditions are mild, and a process is simple; and the main byproduct benzoic acid compound generated by the reaction can be recycled by washing, extracting and desolventizing in post-treatment, and then is used as a reaction raw material for preparing the benzophenone derivative again, so wastewater treatment cost is reduced, and resources are fully utilized.
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Paragraph 0054-0059

(2021/06/22)

Cu (II) Schiff base complex grafted guar gum: Catalyst for benzophenone derivatives synthesis
In this study Guar gum based Cu(II) Schiff's base complex (GG-Cu) has been synthesized and characterized by FT-IR, PXRD, UV–vis, TGA, XPS, FESEM, TEM, EDAX, solid-state NMR, Elemental mapping, CHNS and AAS analysis. This moiety has been found to be an efficient heterogeneous catalyst for selective oxidation reactions. Fifteen model reactions have been carried to establish the catalytic behavior of GG-Cu, and five of these yield novel products. The ease of separation of catalyst from the reaction mixture simply by filtration is an added advantage; furthermore the catalyst can be reused up to five times without significant loss of catalytic activity. The overall concept of developing newer, efficient and environmental benign catalysts with ease of separation and recycling ability has been successfully demonstrated. All of the isolated products were fully characterized on the basis of their physical and spectral data.
Krishna,Kumari, Shweta,Sharma, Sunil K.,Yadav, Deepak
(2020/06/01)

Base-free oxidation of alcohols enabled by nickel(ii)-catalyzed transfer dehydrogenation
An efficient nickel(ii)-catalyzed transfer dehydrogenation oxidation of alcohols is reported that relies on cyclohexanone as the formal oxidant and does not require the use of an external base. The synthetic utility of this protocol is demonstratedviathe facile oxidation of structurally complicated natural products.
Ye, Danfeng,Liu, Zhiyuan,Sessler, Jonathan L.,Lei, Chuanhu
supporting information
p. 11811 - 11814
(2020/10/13)

A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for aerobic oxidation of alcohols
A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for the aerobic oxidation of alcohols has been developed for the first time, and the photoredox aerobic oxidation of secondary and primary alcohols provided the corresponding ketones and carboxylic acids, respectively, in high to excellent yields.
Zhu, Xianjin,Liu, Can,Liu, Yong,Yang, Haijun,Fu, Hua
p. 12443 - 12446
(2020/10/30)

Scalable Aerobic Oxidation of Alcohols Using Catalytic DDQ/HNO3
A selective, practical, and scalable aerobic oxidation of alcohols is described that uses catalytic amounts of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HNO3, with molecular oxygen serving as the terminal oxidant. The method was successfully applied to the oxidation of a wide range of benzylic, propargylic, and allylic alcohols, including two natural products, namely, carveol and podophyllotoxin. The conditions are also applicable to the selective oxidative deprotection of p-methoxybenzyl ethers.
Arseniyadis, Stellios,Clavier, Louis,Copin, Chloé,Fournier, Jean,Giffard, Jean-Fran?ois,Jean, Alexandre,Katsina, Tania,Macedo Portela Da Silva, Nayane,Tamion, Rodolphe
supporting information
p. 856 - 860
(2020/07/14)

Photo-induced phosphorus radical involved semipinacol rearrangement reaction: Highly synthesis of γ-oxo-phosphonates
Hydroxyphosphoric acids display the unique biological activities, and they have some attractive prospects as clinical drug moleculars. Herein, a new approach for the synthesis of γ-oxo-phosphonates (the precursor of hydroxyphosphoric acid) has been established through the semipinacol rearrangement tactic involved the photo-induced phosphorus radical process. Most important, this transformation is avoid of the external oxidants, and occurs very well under the sunlight irradiation, meanwhile the γ-oxo-phosphonate was easily derivatized to obtain γ-hydroxyphosphoric acid, thus highlights the synthesis value of this method.
Wang, Chunhai,Huang, Xiaoling,Liu, Xueting,Gao, Suqian,Zhao, Bin,Yang, Shangdong
supporting information
p. 677 - 680
(2019/08/27)

Novel process for producing phenyl fluoride, diphenyl ketone fluoride, and derivatives thereof
The invention relates to a novel process for producing phenyl fluoride, diphenyl ketone fluoride, and derivatives thereof, especially the phenyl fluoride and derivatives thereof. The invention especially relates to a novel environment-friendly process for synthesizing phenyl fluoride and diphenyl ketone fluoride, which are the raw materials for preparing polyaryl-ether-ketone PAEK. The invention discloses the method that is more effective and environment-friendly for preparing the compounds through a Friedel-Crafts reaction, and further a more environment-friendly process, and provdies beneficial catalysts. Another object of the present invention is to employ the Friedel-Crafts reaction and adopts the beneficial catalysts, wherein the catalyst can be easily combined with the fluoridation reaction which can be carried out before, or after the Friedel-Crafts reaction. Herein, another object of the invention is to use the catalyst in the Friedel-Crafts reaction, wherein the catalyst can work in both the Friedel-Crafts reaction and the fluoridation reaction.
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(2020/07/02)

Water Phase, Room Temperature, Ligand-Free Suzuki–Miyaura Cross-Coupling: A Green Gateway to Aryl Ketones by C–N Bond Cleavage
We report herein a green strategy for synthesis of aryl ketones from twisted amides by using Pd(OAc)2 as catalysts. This method shows high functional group tolerance to offer a variety of ketones in good yields under mild conditions (up to 94 %). Notably, this methodology demonstrates the first water phase, room temperature, ligand-free Suzuki–Miyaura coupling through C–N bond cleavage, which is environmentally friendly and might facilitate the development of amide based green chemistry.
Zhang, Yuqi,Wang, Zijia,Tang, Zhao,Luo, Zhongfeng,Wu, Hongxiang,Liu, Tingting,Zhu, Yulin,Zeng, Zhuo
p. 1620 - 1628
(2020/03/04)

Preparation method of high-purity 4, 4 '-difluorobenzophenone
The invention discloses a preparation method of high-purity 4, 4 '-difluorobenzophenone. 4, 4'-difluorobenzophenone is prepared by adopting p-fluorobenzaldehyde and fluorobenzene as catalysts througha one-step method, and the purity can reach about 99.999%; the method can be applied to the pharmaceutical industry and the special engineering plastic industry, and particularly can be applied to preparation of medical-grade polyether-ether-ketone. The preparation method is high in yield, high in product purity, easy in reaction control and free of risks such as explosion.
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Paragraph 0013-0022

(2020/08/02)

ε-Caprolactone manufacture via efficient coupling Baeyer-Villiger oxidation with aerobic oxidation of alcohols
To avoid the use of peracids oxidant or highly concentrated hydrogen peroxide which is potentially hazardous and explosive, herein, a new route to ε-caprolactone was developed in which molecule oxygen was employed as the terminal oxidant. The commercial available N-hydroxyphthalimide and ammonium cerium nitrate were used as the key catalysts for the increased yield of ε-caprolactone. For instance, the selectivity of ε-caprolactone was obtained 92 % with 85 % conversion of cyclohexanone which was comparable to the strategies using highly concentrated hydrogen peroxide. The sacrificed alcohols were transformed into corresponding ketones which were also valuable chemicals. Furthermore, the efficiency of the alcohols was achieved to unprecedented 52 %. The Baeyer-Villiger oxidation of various other cycloalkanones was also examined. The substituent group effect on the efficiency of sacrificed alcohols was investigated in which weak electron-donating substituent induced nearly quantitative yield of ε-caprolactone. The reaction mechanism was studied with the help of electron paramagnetic resonance which indicated the existence of a radical pathway.
Du, Renfeng,Li, Haoran,Wang, Yongtao,Yao, Jia,Yuan, Haoran,Zhao, Chenxuan
(2020/04/27)

A palladium-catalyzed C-H functionalization route to ketones: Via the oxidative coupling of arenes with carbon monoxide
We describe the development of a new palladium-catalyzed method to generate ketones via the oxidative coupling of two arenes and CO. This transformation is catalyzed by simple palladium salts, and is postulated to proceed via the conversion of arenes into high energy aroyl triflate electrophiles. Exploiting the latter can also allow the synthesis of unsymmetrical ketones from two different arenes.
Arndtsen, Bruce A.,Kinney, R. Garrison,Levesque, Taleah M.
p. 3104 - 3109
(2020/03/27)

Functional Porous Organic Polymers Comprising a Triaminotriphenylazobenzene Subunit as a Platform for Copper-Catalyzed Aerobic C-H Oxidation
Developing functional porous materials as a platform for the heterogeneous catalytic oxidation reaction provides a good way to solve the high environmental issues resulted by traditional oxidation processes in the industry. This article reported a design and facile synthesis of N-rich functional porous organic polymers with mesopores such as Azo-POP-4, Azo-POP-5, and Azo-POP-6 based on the triaminotriphenylazobenzene subunit for the first time. The nitrogen-rich POPs with the triaminotriphenylazobenzene subunit was found to remove 85% of copper ions from water within 30 min. The as-synthesized Cu@Azo-POP-4 demonstrated high catalytic reactivity and selectivity in aerobic C-H bond oxidation to afford the desired ketones in high yield. In addition, the catalyst could be reused easily five times without decreasing the reactivity, which will help to design catalysts reducing environmental pollution and advance the chemical technology.
Liu, Xiangxiang,Luo, Xian-Sheng,Deng, Han-Lin,Fan, Wenhao,Wang, Shuifeng,Yang, Chaojie,Sun, Xiao-Yu,Chen, Shi-Lu,Huang, Mu-Hua
p. 5421 - 5430
(2019/08/20)

Cercosporin-bioinspired selective photooxidation reactions under mild conditions
The development of an efficient system for selective oxidation of organic compounds to generate more valuable compounds with molecular oxygen is a significant challenge in industrial chemistry. Bioinspired by the ability of naturally occurring perylenequinonoid pigments (PQPs) to generate reactive oxygen species (ROS) upon photoirradiation, here we report that cercosporin, one of the perylenequinonoid pigments, can function as a cost-effective and environmentally friendly photocatalyst for a wide range of selective oxidations, including benzylic C-H bonds to carbonyls, amines to aldehydes, and sulfides to sulfoxides. All of the representative reactions proceeded smoothly with high efficiency under mild conditions. Owing to the use of inexpensive metal-free visible light-driven photocatalyst produced from microbial fermentation with cheap glucose as the starting material and the ease of handling, we expect that this developed method will be particularly attractive for many more applications in synthetic transformation.
Li, Jia,Bao, Wenhao,Tang, Zhaocheng,Guo, Baodang,Zhang, Shiwei,Liu, Haili,Huang, Shuping,Zhang, Yan,Rao, Yijian
supporting information
p. 6073 - 6081
(2019/11/20)

Method for preparing symmetric diarylketone through catalytic oxidative carbonylation
The invention discloses a method for preparing symmetric diarylketone of a formula (I) as shown in the description. The method comprises the following steps: mixing arylboronic acid (II) (Ar-B(OH)2 (II)), a palladium catalyst, a promoter and an organic solvent in a reactor, introducing air and CO having a volume ratio of (7-19):1, reacting under the conditions of a pressure of 1-6 atm and a temperature of 30-80 DEG C for 8-16 hours, and performing after-treatment on the reaction solution, thereby obtaining the product symmetric diarylketone. According to the method disclosed by the invention,the air directly serves as an oxidizing agent to replace the O2 to be applied to oxidative carbonylation of the arylboronic acid, and the ratio of the air to CO is beyond an explosion limit. Therefore, the catalytic system is safe and economic. The palladium catalyst is small in dosage and simple in separation and can be recycled for several times. The method disclosed by the invention is mild inreaction condition, excellent in substrate suitability and high in yield.
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Paragraph 0023; 0024; 0025; 0026; 0028

(2019/03/08)

Efficient acceptorless photo-dehydrogenation of alcohols and: N -heterocycles with binuclear platinum(ii) diphosphite complexes
Although photoredox catalysis employing Ru(ii) and Ir(iii) complexes as photocatalysts has emerged as a versatile tool for oxidative C-H functionalization under mild conditions, the need for additional reagents acting as electron donor/scavenger for completing the catalytic cycle undermines the practicability of this approach. Herein we demonstrate that photo-induced oxidative C-H functionalization can be catalysed with high product yields under oxygen-free and acceptorless conditions via inner-sphere atom abstraction by binuclear platinum(ii) diphosphite complexes. Both alcohols (51 examples), particularly the aliphatic ones, and saturated N-heterocycles (24 examples) can be efficiently dehydrogenated under light irradiation at room temperature. Regeneration of the photocatalyst by means of reductive elimination of dihydrogen from the in situ formed platinum(iii)-hydride species represents an alternative paradigm to the current approach in photoredox catalysis.
Zhong, Jian-Ji,To, Wai-Pong,Liu, Yungen,Lu, Wei,Che, Chi-Ming
p. 4883 - 4889
(2019/05/16)

Aerobic oxidation of alcohols with air catalyzed by decacarbonyldimanganese
The oxidation of alcohols to carbonyl compounds using air as the terminal oxidant is highly desirable. As described in previous reports, the abstraction of α-H of the alcohol is the most important step, and it typically requires not only a metal catalyst but also complex ligands, co-catalysts and bases. Herein, we report a practical and efficient method for the oxidation of primary alcohols, secondary alcohols, 1,2-diols, 1,2-amino alcohols, and other α-functionalized alcohols using a commercially available catalyst, Mn2(CO)10, and no additives. Preliminary mechanistic studies indicated that an alkoxyl radical intermediate existed in our system, and a plausible mechanism consistent with the experimental results and literature was proposed.
Meng, Shan-Shui,Lin, Li-Rong,Luo, Xiang,Lv, Hao-Jun,Zhao, Jun-Ling,Chan, Albert S. C.
supporting information
p. 6187 - 6193
(2019/11/20)

A Deoximation Method for Deprotection of Ketones and Aldhydes Using a Graphene-Oxide-Based Co-catalysts System
The deoximation of a wide range of ketoximes and aldoximes to their corresponding carbonyl compounds with high yields has been achieved using graphene oxide (GO) and sodium nitrite (NaNO2) as highly efficient catalysts and air as the green oxidant under mild conditions. The mechanism of deprotection and recycling use of catalyst were revealed in deep experiment. The carboxylic acid groups on the GO were essential for high catalytic activity. (Figure presented.).
Tong, Qiaolin,Liu, Yang,Gao, Xuezhi,Fan, Zhanfang,Liu, Tianfu,Li, Bo,Su, Dangsheng,Wang, Qinghe,Cheng, Maosheng
supporting information
p. 3137 - 3145
(2019/05/01)

Iron-Enabled Utilization of Air as the Terminal Oxidant Leading to Aerobic Oxidative Deoximation by Organoselenium Catalysis
In contrast to conventional organoselenium-catalyzed oxidation reactions that require peroxide oxidants such as hydrogen peroxide, in this work we found that, addition of a low loading of iron (II) could enable the successful utilization of air as the terminal oxidant in organoselenium-catalyzed oxidative deoximation reaction of ketoximes. This led to a new mild and relatively green aerobic oxidative deoximation method. Control reactions and X-ray photoelectron spectroscopy (XPS) analysis suggest that iron is crucial in the catalytic cycle, working to prohibit the deactivation of selenium catalyst through an iron-catalyzed aerobic oxidation of low valent selenium species by air to the active high valent selenium species. Since air can be utilized as the terminal oxidant, this work may contribute to the advance of organoselenium catalysis. (Figure presented.).
Chen, Chao,Zhang, Xu,Cao, Hongen,Wang, Fang,Yu, Lei,Xu, Qing
p. 603 - 610
(2018/12/14)

Template-Directed Synthesis of Photocatalyst-Encapsulating Metal-Organic Frameworks with Boosted Photocatalytic Activity
In the past decade, the use of visible light to promote organic transformations has gained intense attention. In this study, we developed a template-directed synthesis method to use homogeneous Ru and Ir photocatalysts as structure-directing templates and succeeded to prepare a series of photocatalyst-encapsulating metal-organic frameworks (photocatalyst@MOFs) with zeolite-like structures. The open channels and polyhedral cages of MOFs effectively dispersed the encapsulated photocatalysts and facilitated the transport of reactants and products, leading to boosted catalytic activity and good reusability toward important organic reactions such as aerobic oxidation reaction of benzyl halides and the cyclization of tertiary anilines and maleimides under visible light. Moreover, we also demonstrate the versatility and universality of our templating strategy. It not only can form MOFs which cannot be accessed by other synthesis methods, but also can encapsulate various commercially available homogeneous photocatalysts into MOFs. This work explores an avenue to prepare heterogeneous photocatalysts to catalyze value-added reactions.
Yang, Xiaojie,Liang, Tao,Sun, Jiaxing,Zaworotko, Michael J.,Chen, Yao,Cheng, Peng,Zhang, Zhenjie
p. 7486 - 7493
(2019/08/26)

Synthesis of Benzylic Alcohols by C-H Oxidation
Selective methylene C-H oxidation for the synthesis of alcohols with a broad scope and functional group tolerance is challenging due to the high proclivity for further oxidation of alcohols to ketones. Here, we report the selective synthesis of benzylic alcohols employing bis(methanesulfonyl) peroxide as an oxidant. We attempt to provide a rationale for the selectivity for monooxygenation, which is distinct from previous work; a proton-coupled electron transfer mechanism (PCET) may account for the difference in reactivity. We envision that our method will be useful for applications in the discovery of drugs and agrochemicals.
Tanwar, Lalita,B?rgel, Jonas,Ritter, Tobias
supporting information
p. 17983 - 17988
(2019/11/14)

Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions
Despite significant progress in aliphatic decarboxylation, an efficient and general protocol for radical aromatic decarboxylation has lagged far behind. Herein, we describe a general strategy for rapid access to both aryl and alkyl radicals by photosensitized decarboxylation of the corresponding carboxylic acids esters followed by their successive use in divergent carbon–heteroatom and carbon–carbon bond-forming reactions. Identification of a suitable activator for carboxylic acids is the key to bypass a competing single-electron-transfer mechanism and “switch on” an energy-transfer-mediated homolysis of unsymmetrical σ-bonds for a concerted fragmentation/decarboxylation process.
Patra, Tuhin,Mukherjee, Satobhisha,Ma, Jiajia,Strieth-Kalthoff, Felix,Glorius, Frank
p. 10514 - 10520
(2019/07/12)

Aerobic Oxygenation of Alkylarenes over Ultrafine Transition-Metal-Containing Manganese-Based Oxides
The oxygenation of alkylarenes to the corresponding aryl ketones is an important reaction, and the development of efficient heterogeneous catalysts that can utilize O2 as the sole oxidant is highly desired. In this study, we developed an efficient alkylarene oxygenation process catalyzed by ultrafine transition-metal-containing Mn-based oxides with spinel or spinel-like structures (M-MnOx, M=Fe, Co, Ni, Cu). These M-MnOx catalysts were prepared by a low-temperature reduction method in 2-propanol-based solutions using tetra-n-butyl ammonium permanganate (TBAMnO4) as the Mn source, and they exhibited high Brunauer–Emmett–Teller surface areas (typically >400 m2 g?1). Using fluorene as the model substrate, the catalytic activities of M-MnOx and Mn3O4 were compared. The catalytic activities of M-MnOx were significantly higher than that of Mn3O4, which demonstrates that the incorporation of transition metals in manganese oxide was critical. Among the series of M-MnOx catalysts examined, Ni-MnOx exhibited the highest catalytic activity for the oxygenation. In addition, the catalytic activity of Ni-MnOx was higher than that of a physical mixture of Mn3O4 and NiO. Furthermore, Ni-MnOx exhibited a broad substrate scope with respect to various types of structurally diverse (hetero)alkylarenes (16 examples). The observed catalysis was truly heterogeneous, and the Ni-MnOx catalyst was reusable for the oxygenation of fluorene at least three times and its high catalytic performance was preserved, for example, the reaction rate, final product yield, and product selectivity. The present Ni-MnOx-catalyzed oxygenation process is possibly initiated by a single-electron oxidation process, and herein a plausible oxygen-transfer mechanism is proposed based on several pieces of experimental evidence.
Nakai, Satoru,Uematsu, Tsubasa,Ogasawara, Yoshiyuki,Suzuki, Kosuke,Yamaguchi, Kazuya,Mizuno, Noritaka
p. 1096 - 1106
(2018/01/15)

Method for removing oxime through catalysis of tellurium
The invention provides a method for removing oxime through catalysis of tellurium and relates to the technical field of oxime removal. According to the method provided by the invention, commercializeddiphenyl ditelluride ether is used as a catalyst; oxygen gas is used as an oxidant under a solvent-free condition and oxime is heated so that oxime can be removed to obtain a carbonyl compound; the catalyst also can be repeatedly utilized. The method is clean and environmentally friendly, low in cost and safe to operate, so that the method is an effective oxime removing method. According to the method provided by the invention, raw materials are selected from various aryl or alkyl substituted oxime. According to the method provided by the invention, reaction does not need a solvent so that the reaction cost can be reduced and a process is clean and environmentally friendly. The oxidant provided by the invention is the oxygen gas and can be used for sufficiently oxidizing a substrate, andthe yield is the highest.
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Paragraph 0014; 0023; 0024

(2018/07/15)

2-Iodo-N-isopropyl-5-methoxybenzamide as a highly reactive and environmentally benign catalyst for alcohol oxidation
Several N-isopropyliodobenzamides were evaluated as catalysts for the oxidation of benzhydrol to benzophenone in the presence of Oxone (2KHSO5·KHSO4·K2SO4) as a co-oxidant at room temperature. A study on the substituent effect of the benzene ring of N-isopropyl-2-iodobenzamide on the oxidation revealed that its reactivity increased in the following order of substitution: 5-NO2 2Me, 3-OMe 5-OAc 5-Cl H, 4-OMe 5-Me 5-OMe. The oxidation of various benzylic and aliphatic alcohols using a catalytic amount of the most reactive 5-methoxy derivative successfully resulted in moderate to excellent yields of the corresponding carbonyl compounds. The high reactivity of the 5-methoxy derivative at room temperature is a result of the rapid generation of the pentavalent species from the trivalent species during the reaction. 5-Methoxy-2-iodobenzamide would be an efficient and environmentally benign catalyst for the oxidation of alcohols, especially benzylic alcohols.
Yakura, Takayuki,Fujiwara, Tomoya,Yamada, Akihiro,Nambu, Hisanori
supporting information
p. 971 - 978
(2019/11/11)

CO2-Catalyzed oxidation of benzylic and allylic alcohols with DMSO
CO2-catalyzed transition-metal-free oxidation of alcohols has been achieved. Earlier, several methodologies have been explored for alcohol oxidations based on transition-metal catalysts. However, owing to the cheaper price, easy separation and nontoxicity, transition-metal-free systems are in high demand to the pharmaceutical industries. For this reason, various primary and secondary alcohols have been selectively oxidized to the corresponding carbonyl compounds using CO2 as a catalyst in the presence of different functional groups such as nitrile, nitro, aldehyde, ester, halogen, ether, and so on. At the end, transition-metal-free syntheses of pharmaceuticals have also been achieved. Finally, the role of CO2 has been investigated in detail, and the mechanism is proposed on the basis of experiments and DFT calculations.
Riemer, Daniel,Mandaviya, Bhavdip,Schilling, Waldemar,G?tz, Anne Charlotte,Kühl, Torben,Finger, Markus,Das, Shoubhik
p. 3030 - 3034
(2018/04/14)

The cytochrome: C -cyclo[6]aramide complex as a supramolecular catalyst in methanol
A hydrogen-bonded macrocycle, cyclo[6]aramide, was found to form a supramolecular complex with cytochrome c, which enables the solubilization of the heme protein in methanol. The supramolecular complexation was evidenced by UV-vis, CD, and Raman spectroscopic techniques via structural characterization. Computational simulation based on the DFT method reveals the presence of strong hydrogen bonds formed between the lysine residues exposed on the protein surface and the oxygen atoms residing in the cavity of cyclo[6]aramide apart from cation-π interactions. The resulting cytochrome c-cyclo[6]aramide 1 exhibited higher activities than unmodified cytochrome c in the oxidation of benzhydrol to benzophenone with hydrogen peroxide at low temperatures. The enhanced activity with lowering temperature up to -40 °C indicates that the complex can act as a "cold-active" synzyme. The results achieved here demonstrate the potential of hydrogen-bonded macrocycles in supramolecular chemistry for catalytic reactions via ligand-protein interactions.
Pan, Wang,Mao, Lijun,Shi, Mingsong,Fu, Yonghong,Jiang, Xiaomin,Feng, Wen,He, Youzhou,Xu, Dingguo,Yuan, Lihua
supporting information
p. 3857 - 3866
(2018/03/06)

MeZnOMe-mediated reaction of aldehydes with Grignard reagents: A glance into nucleophilic addition/Oppenauer oxidation pathway
A novel organozincate of RMgX ?MeZnOMe ?LiCl type, formed in situ via transmetalation of Grignard reagent RMgBr ?LiCl with MeZnOMe, is shown to be an excellent organometallic species in the nucleophilic addition/Oppenauer oxidation of aldehydes to generate aromatic ketones in high yield. This transformation allows quick access to structurally diverse aryl, heteroaryl, benzyl and alkyl ketones with broad substrate scope and excellent functional group tolerance.
Fu, Ying,Ma, Xian-Zhen,Shi, Chun-Zhao,Shen, Tong,Du, Zhengyin
(2018/07/31)

One-pot method for preparing high-purity 4,4'-difluorodiphenylketone
The invention discloses a one-pot method for preparing high-purity 4,4'-difluorodiphenylketone. According to the method, 4-fluorotoluene is used as a starting raw material and is subjected to oxidation, F-C acylation-condensation, multistage cooling and step-by-step crystallization so as to eventually prepare the target product 4,4'-difluorodiphenylketone. The prepared 4,4'-difluorodiphenylketonehas a melting point of 107 to 109 DEG C and a purity of no less than 99.9%. The method is simple in process; the raw material is cheap and easily available; a catalyst is easy to recover; the 4,4'-difluorodiphenylketone is high in purity; so the method is worth promotion.
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Paragraph 0029; 0033

(2018/05/16)

Hydrogen bond directed aerobic oxidation of amines via photoredox catalysis
An application of H-bonding interactions for directing the α-C-H oxidation of amines to amides and amino-ketones catalyzed by an organic photocatalyst is reported. The high efficiency of this method is demonstrated by the aerobic oxidation of pyrrolidines, diarylamines and benzylamines bearing urea groups with high yields and a wide substrate scope.
Wang, Hongyu,Man, Yunquan,Wang, Kaiye,Wan, Xiuyan,Tong, Lili,Li, Na,Tang, Bo
p. 10989 - 10992
(2018/10/08)

Palladium-Catalyzed Carbonylative Homocoupling of Aryl Iodides for the Synthesis of Symmetrical Diaryl Ketones with Formic Acid
A convenient method for the palladium-catalyzed carbonylative homocoupling of aryl iodides was developed. With formic acid as the CO source, various symmetrical diaryl ketones were synthesized in moderate to good yield in the presence of a palladium catalyst.
Wu, Fu-Peng,Peng, Jin-Bao,Qi, Xinxin,Wu, Xiao-Feng
p. 173 - 177
(2017/11/27)

Revealing the Structure and Reactivity of the Active Species in the FeCl2-TBHP System: Case Study on Alkene Oxidation
A mechanism involving a quintet ferryl [FeIV=O] species has been disclosed for the oxidation of alkene under the FeCl2-TBHP system. Both theoretical and experimental results suggested that the quintet ferryl species [FeIV=O] was produced by the reaction of FeCl2 with TBHP. A Mulliken atomic spin density distribution on [FeIV=O] showed that the O site has strong radical character and could easily react with alkene to form a carbon radical intermediate. This radical could be further oxidized by TBHP to lead to the C=C bond cleavage of alkene.
Huang, Zhiliang,Qi, Xiaotian,Lee, Jyh-Fu,Lei, Aiwen
supporting information
p. 1635 - 1640
(2018/06/11)

Palladium-Catalyzed Decarbonylative Difluoromethylation of Acid Chlorides at Room Temperature
Methods for the direct synthesis of difluoromethylated arenes are sparse, despite the importance of the difluoromethyl group in medical, agro-, and materials chemistry. A palladium-catalyzed decarbonylative cross-coupling reaction of acid chlorides with a difluoromethyl zinc reagent is achieved to access difluoromethylated compounds. The transformation proceeds at room temperature and shows broad functional group tolerance, thus providing a general and efficient method for decarbonylative difluoromethylation of a wide range of aromatic carboxylic acids.
Pan, Fei,Boursalian, Gregory B.,Ritter, Tobias
p. 16871 - 16876
(2018/11/23)

Kumada Arylation of Secondary Amides Enabled by Chromium Catalysis for Unsymmetric Ketone Synthesis under Mild Conditions
The synthesis of aromatic ketones by chromium-catalyzed Kumada arylation of secondary amides with organomagnesium reagents is described. This reaction was enabled by using low-cost chromium(III) salt as a precatalyst, combined with trimethylsilyl chloride
Chen, Changpeng,Liu, Pei,Luo, Meiming,Zeng, Xiaoming
p. 5864 - 5868
(2018/05/29)

Nickel-Catalyzed Molybdenum-Promoted Carbonylative Synthesis of Benzophenones
A nickel-catalyzed molybdenum-promoted carbonylative coupling reaction for the synthesis of benzophenones from aryl iodides has been developed. Various substituted diaryl ketones were synthesized in moderate to excellent yields under CO-gas-free conditions. A synergetic effect of both nickel and molybdenum has been observed, which is also responsible for the success of this transformation.
Peng, Jin-Bao,Wu, Fu-Peng,Li, Da,Qi, Xinxin,Ying, Jun,Wu, Xiao-Feng
p. 6788 - 6792
(2018/06/04)

An Fe3O4@P4VP@FeCl3 core-shell heterogeneous catalyst for aerobic oxidation of alcohols and benzylic oxidation reaction
A novel magnetic Fe3O4@P4VP(poly(4-vinylpyridine))@FeCl3 core-shell structure was successfully synthesized. Its Fe3O4@P4VP core was initially prepared via polymerization of 4-vinyl pyridine on the surface of Fe3O4 microspheres. The successful introduction of the FeCl3 moiety as a catalytic active site was achieved through coordination interaction between P4VP and FeCl3. The obtained Fe3O4@P4VP@FeCl3 catalyst was applied in the selective oxidation of alcohols using molecular oxygen as the oxidant. It was shown that a variety of alcohol substrates is tolerated under optimized reaction conditions. Additionally, benzylic oxidation of hydrocarbon compounds was also evaluated using Fe3O4@P4VP@FeCl3 as the catalyst and tBuOOH as the oxidant, achieving high yields and very good selectivities. The heterogeneity of the Fe3O4@P4VP@FeCl3 core-shell catalyst was tested and the initial activity was maintained after five reuses.
Li, Ruilian,Zhao, Jian,Yang, Fengxia,Zhang, Yingchao,Ramella, Daniele,Peng, Yu,Luan, Yi
p. 51142 - 51150
(2017/11/15)

Direct synthesis of Fe(III) immobilized Zr-based metal–organic framework for aerobic oxidation reaction
A Zr-based metal–organic framework with bipyridine units (UiO-67) has been utilized for the immobilization of catalytically active iron species via a post-synthetic metalation method. UiO-67 bipyridine MOF was synthesized through a simple solvothermal method and was shown to have a UiO-type structure. Post-synthetic metalation of UiO-67 MOF was performed for the immobilization of the catalytically active FeCl3. FT-IR and EDX element map suggested that FeCl3 is coordinately bonded to the UiO-67 bipyridine framework. The synthesized UiO-67-FeCl3 catalyst was used for the aerobic oxidation of alcohols and benzylic compounds in the presence of molecular oxygen. In addition, the UiO-67-FeCl3 catalyst can be reused as a solid heterogeneous catalyst without compromising its activity and selectivity.
Shu, Xin,Yu, Ying,Jiang, Yi,Luan, Yi,Ramella, Daniele
(2017/09/30)

T-BuONa-Mediated Transition-Metal-Free Autoxidation of Diarylmethanes to Ketones
Autoxidative sp3 C-H transformation of diarylmethanes has been demonstrated using O2-mediation by t-BuONa. This protocol enables an alternative route for the access to diaryl ketones from benzyl derivatives in good to excellent yields under mild reaction conditions, without transition metal catalysts or additional chemical oxidants.
Li, Jiang-Sheng,Yang, Fan,Yang, Qian,Li, Zhi-Wei,Chen, Guo-Qin,Da, Yu-Dong,Huang, Peng-Mian,Chen, Chao,Zhang, Yuefei,Huang, Ling-Zhi
supporting information
p. 994 - 998
(2017/05/10)

Cu(I) Coordination Polymers as the Green Heterogeneous Catalysts for Direct C-H Bonds Activation of Arylalkanes to Ketones in Water with Spatial Confinement Effect
To develop coordination polymers (CPs) as catalysts to selectively catalyze the reaction of C-H bond activation of arylalkanes to their homologous ketones, three new Cu(I)-based coordination polymers (CuI-CPs) [CuI(aas-TPB)]n (1), [CuBr(ass-TPB)CH3CN]n (2), and {[Cu(ass-TPB)]Cl}n (3) (TPB = N,N,N-tris(3-pyridinyl)-1,3,5-benzenetricarboxamide) were synthesized. Structural variations from a herringbone fashion one-dimensional framework of 1 to a two-dimensional framework of 2 containing a 48-membered macrocycle and a cationic three-dimensional framework of 3 filled with Cl- anions were observed arising from the different halogen ions (I-, Br-, and Cl-). 1-3 were used as the green heterogeneous catalysts to catalyze direct C-H bond activation reactions of arylalkanes to ketones under mild reaction conditions with water as solvent. Handy product separation, convenient reaction procedures, and recyclability of these catalysts make the catalytic system fascinating. Moreover, the CuI-CPs performed the reaction with high regioselectivity due to the unique spatial confinement effect of CPs.
Wang, Xiaolu,Liu, Mengjia,Wang, Yuqing,Fan, Hongyan,Wu, Jie,Huang, Chao,Hou, Hongwei
p. 13329 - 13336
(2017/11/15)

Cu(II)-Catalyzed Ligand-Free Oxidation of Diarylmethanes and Second Alcohols in Water
We developed a simple and efficient Cu(II)-catalyzed ligand-free oxidation of diarylmethanes and secondary alcohols using 70% tert-butyl hydroperoxide (TBHP) in water. A series of diarylmethanes were directly oxidized into diaryl ketones in 67%–98% yields. Additionally, various secondary alcohols were also transformed into the desired products in 48%–98% yields. Importantly, the catalytic system in the absence of any organic solvent, surfactant, or phase transfer agent, had a wide substrate scope and a high tolerance for various functional groups.
Wu, Jianglong,Liu, Yan,Ma, Xiaowei,Liu, Ping,Gu, Chengzhi,Dai, Bin
supporting information
p. 1391 - 139
(2017/09/30)

In Situ-Induced Synthesis of Magnetic Cu-CuFe2O4@HKUST-1 Heterostructures with Enhanced Catalytic Performance for Selective Aerobic Benzylic C-H Oxidation
The multifunctional design of heterogeneous catalysts which can realize the selective oxidation of C-H bonds with oxygen at low temperature is of crucial importance in the catalysis community. Here, we report the designed synthesis of Cu-CuFe2O4@HKUST-1 heterostructures that is highly active for the selective oxidation of benzylic C-H bonds under mild conditions (60 °C). In the synthetic process, the Cu(0) component of Cu-CuFe2O4 nanoparticles gradually released Cu2+ ions which were in situ transformed into the HKUST-1 shell. The high activity can be attributed to a rationally multifunctional design of Cu-CuFe2O4@HKUST-1 heterostructures, in which Cu-CuFe2O4 can provide multiple active sites while HKUST-1 attracts and preconcentrates molecular oxygen. Notably, the catalytic performance under optimized reaction conditions (60 °C) was achieved in the oxidation of fluorene to fluorenone (conversion: > 99%, selectivity: > 99%). Furthermore, the Cu-CuFe2O4@HKUST-1 catalyst could be easily recovered by magnetic separation and reused for 10 times without significant loss of catalytic activity.
Fan, Shuang,Dong, Wenjun,Huang, Xiubing,Gao, Hongyi,Wang, Jingjing,Jin, Zhaokui,Tang, Jia,Wang, Ge
p. 243 - 249
(2017/06/07)

A kind of alkali to promote self-oxidation of diaryl alkane preparation diarylketones method (by machine translation)
The invention discloses a kind of alkali to promote self-oxidation of diaryl alkane preparation diarylketones method. The method is that the diaryl paraffins compound is dissolved in an organic solvent in the drying of, the addition of a base, in the 25 - 80o C reaction under air or oxygen atmosphere for 0.5 - 5 hours, to obtain diarylketones; said two aryl paraffins compound and alkali molar ratio of 1:1 - 1:3. The method overcomes the need in the prior art strong acid or expensive metal reagent or a strong oxidizing agent and the like, has the following advantages: 1) to oxygen as the oxidizing agent, avoids the use of strong or expensive chemical oxidizing agent; 2) transition metal-free catalyst, avoids the heavy metal ion in the product; 3) the process is simple, low cost, wide range of the substrate, friendly to the environment. The synthesis method disclosed in this invention in the preparation of diarylketones industrialization of the play an important role in the production. (by machine translation)
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Paragraph 0019

(2017/08/28)