- Triphenylamine-functionalized tetraphenylpyrazine: Facile preparation and multifaceted functionalities
-
Aggregation-induced emission (AIE) is a unique photo-physical phenomenon and has become an emerging and hot research area. With the enthusiastic efforts paid by researchers, hundreds of AIE-active luminogens (AIEgens) have been generated but heterocyclic AIEgens are rarely reported. Recently, we enriched the family of AIEgens and reported a pyrazine-based AIEgen of tetraphenylpyrazine (TPP), which could be facilely functionalized by a post-synthetic strategy. In this work, we further expanded the TPP-based AIE system by covalently attaching one, two or four electron-donating triphenylamine moieties to the TPP core via Suzuki coupling, and TPP-TPA, TPP-2TPA and TPP-4TPA were produced, respectively. Thanks to their donor-π-acceptor structures, these luminogens exhibit multi-functional properties, such as excellent thermal stability (up to 504°C), large molar absorptivity, bright emission in the solid state (quantum yields up to 35.2%), solvatochromism, and high two-photon absorption cross-sections (up to 480 GM). Furthermore, using TPP-TPA as the emitting layer, a triple-layer device was fabricated and a turn-on voltage, maximum luminance, current efficiency, power efficiency, and external quantum efficiency of 3.7 V, 17 459 cd m-2, 5.49 cd A-1, 3.18 lm W-1 and 2.88% were realized, respectively. These results indicate a huge potential to develop high-tech applications based on these TPP-based AIEgens.
- Chen, Ming,Nie, Han,Song, Bo,Li, Lingzhi,Sun, Jing Zhi,Qin, Anjun,Tang, Ben Zhong
-
-
Read Online
- Visible-Light-Induced Photocatalytic Oxidative Decarboxylation of Cinnamic Acids to 1,2-Diketones
-
A concerted metallophotoredox catalysis has been realized for the efficient decarboxylative functionalization of α,β-unsaturated carboxylic acids with aryl iodides in the presence of perylene bisimide dye to afford 1,2-diketones.
- Chand, Shiv,Pandey, Anand Kumar,Singh, Rahul,Singh, Krishna Nand
-
p. 6486 - 6493
(2021/05/06)
-
- One-pot cascade synthesis of α-diketones from aldehydes and ketones in water by using a bifunctional iron nanocomposite catalyst
-
A new methodology for the synthesis of α-diketones was reportedviaa one-pot cascade process from aldehydes and ketones catalyzed by a bifunctional iron nanocomposite using H2O2as a green oxidant in water. The one-pot strategy showed excellent catalytic stability, comprehensive suitability of substrates and important practical utility for directly synthesizing biologically active and medicinally valuable N-heterocyclesviaan intermittent process.
- Song, Tao,Zhou, Xin,Wang, Xiaoxue,Xiao, Jianliang,Yang, Yong
-
supporting information
p. 1955 - 1959
(2021/03/26)
-
- Catalyst-Free and Transition-Metal-Free Approach to 1,2-Diketones via Aerobic Alkyne Oxidation
-
A catalyst-free and transition-metal-free method for the synthesis of 1,2-diketones from aerobic alkyne oxidation was reported. The oxidation of various internal alkynes, especially more challenging aryl-alkyl acetylenes, proceeded smoothly with inexpensive, easily handled, and commercially available potassium persulfate and an ambient air balloon, achieving the corresponding 1,2-diketones with up to 85% yields. Meanwhile, mechanistic studies indicated a radical process, and the two oxygen atoms in the 1,2-diketons were most likely from persulfate salts and molecular oxygen, respectively, rather than water.
- Shen, Duyi,Wang, Hongyan,Zheng, Yanan,Zhu, Xinjing,Gong, Peiwei,Wang, Bin,You, Jinmao,Zhao, Yulei,Chao, Mianran
-
p. 5354 - 5361
(2021/05/05)
-
- A Bifunctional Iron Nanocomposite Catalyst for Efficient Oxidation of Alkenes to Ketones and 1,2-Diketones
-
We herein report the fabrication of a bifunctional iron nanocomposite catalyst, in which two catalytically active sites of Fe-Nx and Fe phosphate, as oxidation and Lewis acid sites, were simultaneously integrated into a hierarchical N,P-dual doped porous carbon. As a bifunctional catalyst, it exhibited high efficiency for direct oxidative cleavage of alkenes into ketones or their oxidation into 1,2-diketones with a broad substrate scope and high functional group tolerance using TBHP as the oxidant in water under mild reaction conditions. Furthermore, it could be easily recovered for successive recycling without appreciable loss of activity. Mechanistic studies disclose that the direct oxidation of alkenes proceeds via the formation of an epoxide as intermediate followed by either acid-catalyzed Meinwald rearrangement to give ketones with one carbon shorter or nucleophilic ring-opening to generate 1,2-diketones in a cascade manner. This study not only opens up a fancy pathway in the rational design of Fe-N-C catalysts but also offers a simple and efficient method for accessing industrially important ketones and 1,2-diketones from alkenes in a cost-effective and environmentally benign fashion.
- Ma, Zhiming,Ren, Peng,Song, Tao,Xiao, Jianliang,Yang, Yong,Yuan, Youzhu
-
p. 4617 - 4629
(2020/05/19)
-
- Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls
-
2,3-Dichloropyridine N-oxide, a novel oxygen transfer reagent, allows the conductance of the gold(I)-catalyzed oxidation of alkynes to 1,2-dicarbonyls in the absence of any acid additives and under mild conditions to furnish the target species, including those derivatized by highly acid-sensitive groups. The developed strategy is effective for a wide range of alkyne substrates such as terminal- and internal alkynes, ynamides, alkynyl ethers/thioethers, and even unsubstituted acetylene (40 examples; yields up to 99%). The oxidation was successfully integrated into the trapping of reactive dicarbonyls by one-pot heterocyclization and into the synthesis of six-membered azaheterocycles. This synthetic acid-free route was also successfully applied for the total synthesis of a natural 1,2-diketone.
- Dubovtsev, Alexey Yu.,Shcherbakov, Nikolay V.,Dar'in, Dmitry V.,Kukushkin, Vadim Yu.
-
p. 745 - 757
(2020/02/04)
-
- Visible light-induced aerobic oxidation of diarylalkynes to α-diketones catalyzed by copper-superoxo at room temperature
-
We have developed the visible light induced simple copper(ii) chloride catalyzed oxidation of diarylacetylenes to α-diketones by molecular oxygen at room temperature. The in situ generated copper(ii)-superoxo complex is a light-absorbing species that oxidizes inert diarylacetylenes to α-diketones. In contrast to reported photochemical processes, the current oxidation protocol does not require any exogenous photocatalyst or radical initiator. The green chemistry metrics evaluation signifies that the E-factor for the current oxidation process is ~2.3 times better than that of reported photochemical processes. The current reaction scores 63 on the EcoScale of 0-100, indicating an adequate synthesis process. Thus, the overall oxidation process is simple, environmentally benign, and economically feasible. This journal is
- Charpe, Vaibhav Pramod,Hwang, Kuo Chu,Sagadevan, Arunachalam
-
supporting information
p. 4426 - 4432
(2020/08/10)
-
- Gold-Catalyzed Oxidation of Internal Alkynes into Benzils and its Application for One-Pot Synthesis of Five-, Six-, and Seven-Membered Azaheterocycles
-
Internal alkynes have been shown to undergo oxidation to substituted benzils (1,2-diarylethane-1,2-diones) by α-picoline N-oxide in the presence of Ph3PAuNТf2 (5 mol-%). In addition to the unsubstituted benzil, the method allows preparing, under markedly mild conditions (50 °C in chlorobenzene), various non-symmetrical products, including heteroaromatic versions thereof which are much more difficult to obtain otherwise. This gold(I)-catalyzed transformation was integrated into one-pot reaction sequence delivering a range of 5- to 7-membered ring systems (imidazoles, quinoxalines, 1,2,4-triazines, pyrazines, and 1,4-diazepines), thus linking these important heterocyclic motifs to the internal alkyne reagent space.
- Dubovtsev, Alexey Yu.,Dar'in, Dmitry V.,Krasavin, Mikhail,Kukushkin, Vadim Yu.
-
p. 1856 - 1864
(2019/02/19)
-
- Sequentially Pd/Cu-Catalyzed Alkynylation-Oxidation Synthesis of 1,2-Diketones and Consecutive One-Pot Generation of Quinoxalines
-
We report a simple and efficient one-pot synthesis of 1,2-diketones by concatenation of two Pd/Cu-catalyzed processes: Pd0/CuI-catalyzed Sonogashira coupling of terminal alkynes with aryl (pseudo)halides furnishes internal alkynes, which are directly transformed by PdII/CuII-catalyzed Wacker-type oxidation with DMSO and oxygen as dual oxidants to furnish 1,2-diketones. With this efficient, catalyst economical process, various aryl iodides and triflates are efficiently transformed in high yields into symmetrically and unsymmetrically substituted 1,2-diketones with various functional groups. This process can be readily extended to a consecutive one-pot synthesis of quinoxalines in a diversity-oriented fashion.
- Niesobski, Patrik,Martínez, Ivette Santana,Kustosz, Sebastian,Müller, Thomas J. J.
-
supporting information
p. 5214 - 5218
(2019/07/31)
-
- Rate Enhancement in CAN-Promoted Pd(PPh3)2Cl2-Catalyzed Oxidative Cyclization: Synthesis of 2-Ketofuran-4-carboxylate Esters
-
Stoichiometric ceric ammonium nitrate (CAN) and a catalytic amount of Pd(PPh3)2Cl2 (5 mol %) can rapidly produce multisubstituted 2-ketofuran-4-carboxylate esters from 2-propargylic 1,3-ketoesters via oxidative O-cyclization reaction. Pd(PPh3)2Cl2 was found to be the crucial catalyst as its inclusion greatly enhanced the rate of the reaction and cleanly afforded the products within minutes. Over 30 substrates were successfully converted to the desired compounds in mostly moderate to good yields.
- Ruengsangtongkul, Sureeporn,Chaisan, Nattawadee,Thongsornkleeb, Charnsak,Tummatorn, Jumreang,Ruchirawat, Somsak
-
p. 2514 - 2517
(2019/04/30)
-
- Method for synthesizing benzil derivatives
-
The invention discloses a method for synthesizing benzil derivatives. The method comprises the steps that a diphenyl acetylene compound, halogenated ammonium salt or iodine chloride and a sulfur source serve as reactants, the reactants react in a solvent for a period of time, purification is conducted, and then the benzil derivatives are obtained. According to the method, a metal catalyst and toxic iodine are not used, the applied reactants are low in price, poisonless and tasteless, the operation method is simple, the yield is high, aftertreatment is easy, and the method is suitable for industrial production.
- -
-
Paragraph 0039; 0040; 0041; 0042
(2019/01/23)
-
- ICl/AgNO3 Co-catalyzed radical oxidation of diaryl- A nd alkylarylalkynes into 1,2-diketones
-
A novel ICl/AgNO3 co-catalyzed radical oxidation of diaryl- A nd alkylarylalkynes into 1,2-diketones is reported. The reaction proceeded smoothly under mild conditions and generated 1,2-diketones in moderate to good yields with a good tolerance of functional groups. Furthermore, the obtained C4-(1,2-diketoaryl)isoxazoles could react smoothly with 1,2-diaminobenzene to form C4-(3-arylquinoxalin-2-yl)isoxazoles. At last, a new one-pot strategy for the synthesis of quinoxalines from 1,2-diphenylethynes and 1,2-diaminobenzene is also reported.
- Yang, Wen,Chen, Yu,Yao, Yongqi,Yang, Xin,Lin, Qifu,Yang, Dingqiao
-
p. 11080 - 11090
(2019/09/09)
-
- Method for synthesizing 1,2-dicarbonyl compounds
-
The present invention provides a method for synthesizing 1,2-dicarbonyl compounds represented by a formula (II). The method comprises the steps of taking a substituted diphenylacetylene compound represented by a formula (I) as an initial substance, in the presence of an additive, an oxidizing agent and a solvent, conducting a reaction at a temperature of 0-50 DEG C, and conducting post-treatment to obtain a 1,2-dicarbonyl compound represented by the formula (II), wherein the additive is p-toluenesulfonic acid or phenylsulfonic acid. The synthetic method of the invention has the characteristicsof small environmental hazard, mild reaction conditions and simple operation.
- -
-
Paragraph 0066-0077
(2019/03/26)
-
- Electrochemical synthesis of 1,2-diketones from alkynes under transition-metal-catalyst-free conditions
-
We report an electrochemical protocol for the direct oxidation of internal alkynes in air to provide 1,2-diketones. A variety of functional groups and heterocycle-containing substrates can be tolerated well under mild conditions.
- Zhou, Jie,Tao, Xiang-Zhang,Dai, Jian-Jun,Li, Chen-Guang,Xu, Jun,Xu, Hong-Mei,Xu, Hua-Jian
-
supporting information
p. 9208 - 9211
(2019/08/07)
-
- An iodine/DMSO-catalyzed sequential one-pot approach to 2,4,5-trisubstituted-1H-imidazoles from α-methylene ketones
-
A sequential one-pot approach to 2,4,5-trisubstituted imidazoles has been developed from α-methylene ketones and aldehydes. This methodology employs air-moisture stable reaction conditions and an inexpensive iodine/DMSO system affording a diverse range of known and novel (substrate scope) 2,4,5-trisubstituted imidazoles in moderate to excellent yields. The iodine/DMSO system was extended to the domino convergent synthesis of two functionalized intermediates, benzil and benzaldehyde, to produce the final product.
- Jayram, Janeeka,Jeena, Vineet
-
p. 37557 - 37563
(2018/11/26)
-
- Two-Step One-Pot Synthesis of Unsymmetrical (Hetero)Aryl 1,2-Diketones by Addition-Oxygenation of Potassium Aryltrifluoroborates to (Hetero)Arylacetonitriles
-
An efficient one-pot two-step procedure for the synthesis of unsymmetrical (hetero)aryl 1,2-diketones has been developed. The reaction proceeds through a palladium-catalyzed nucleophilic addition of potassium aryltrifluoroborates to aliphatic nitriles followed by a copper-catalyzed aerobic benzylic C–H oxygenation using molecular oxygen as a green oxidant. This represents the first example of the direct synthesis of unsymmetrical diaryl 1,2-diketones from arylacetonitriles. This method utilizes inexpensive, stable, nontoxic, and readily available starting materials, is highly effective in the presence of both electron-rich and electron-poor nitriles and aryltrifluoroborates, and tolerates a wide variety of functional groups. The synthetic utility of this transformation was shown by increasing the scale of the reaction and by carrying out the one-pot protocol for the preparation of quinoxaline and benzimidazole derivatives. A plausible reaction mechanism has also been proposed.
- Kumar, Yogesh,Jaiswal, Yogesh,Kumar, Amit
-
p. 494 - 505
(2018/02/09)
-
- NH4I/EtOCS2K promoted synthesis of substituted benzils from diphenylacetylene derivatives
-
A facile protocol is described for the synthesis of benzil derivatives from readily accessible diarylacetylene derivatives using the NH4I/EtOCS2K system. This novel protocol results in excellent chemoselectivity and provided good to excellent yields. A control experiment indicated that the reaction proceeds via NH4I promoted EtOCS2K dimerization to give the corresponding dixanthogen and subsequent dixanthogen assisted oxidation.
- Jiang, Shaohua,Li, Yibiao,Luo, Xianglin,Huang, Guoling,Shao, Yan,Li, Dongli,Li, Bin
-
supporting information
p. 3249 - 3252
(2018/07/21)
-
- Four-phenyl pyrazine small molecule derivatives, four-phenyl pyrazine polymer and aggregation induced material
-
The invention discloses a tetrapherylpyrazine low-molecular-weight derivate, a tetrapherylpyrazine polymer and an aggregation-induced emission material. The tetrapherylpyrazine low-molecular-weight derivate is of a structure as shown in a formula (1), whe
- -
-
Paragraph 0143-0147
(2017/08/14)
-
- Tandem and chemoselective synthesis of benzil derivatives from styrene and arene diazonium salts
-
A facile and practically applied protocol for synthesis of benzil derivatives using styrene and arene diazonium salts is reported. Pd(OAc)2/SeO2 catalytic system was found to be efficient for chemoselective synthesis of benzil. Selenium dioxide works well as an oxidant under milder reaction conditions. Moderate to very good yields of the desired products were obtained.
- Jadhav, Vilas G.,Sarode, Sachin A.,Nagarkar, Jayashree M.
-
supporting information
p. 1834 - 1838
(2017/04/21)
-
- Copper-catalyzed TEMPO oxidative cleavage of 1,3-diketones and β-keto esters for the synthesis of 1,2-diketones and α-keto esters
-
A copper-catalyzed efficient and practical method has been developed for the synthesis of 1,2-diketones and α-keto esters. TEMPO was used as a radical initiator and scavenger, oxidizing the cleavage of α-methylene of 1,3-diketones and β-keto esters to form 1,2-diketones and α-keto esters. This method provided a general way for the formation of 1,2-dicarbonyl compounds.
- Zhou, Peng-Jun,Li, Cheng-Kun,Zhou, Shao-Fang,Shoberu, Adedamola,Zou, Jian-Ping
-
p. 2629 - 2637
(2017/04/03)
-
- An aryl dione the synthetic method of the compound of
-
The invention relates to a synthesis method of an aryldione compound shown in the formula (III). The synthesis method comprises that a compound shown in the formula (I) and a compound shown in the formula (II) undergo a reaction in an organic solvent in the presence of a catalyst, an oxidizing agent and an assistant to produce the compound shown in the formula (III). In the formula, R1 and R2 respectively represent H, C1-C6 alkyl or halogen. Through reasonable selection and combination of the catalyst, the oxidizing agent, the assistant and the organic solvent, a product yield is high. The synthesis method is novel method for synthesis of the aryldione compound and has a good industrial application value and a good industrial production potential.
- -
-
Paragraph 0052-0055; 0063; 0073; 0074; 0082; 0083; 0091
(2018/02/04)
-
- A method for synthesizing derivatives benzil
-
The invention discloses a method for synthesizing a benzil derivative. The method comprises the following steps: adding epoxy chalcone compound shown in the formula I, a Selectfluor oxidizing agent and inorganic base into a mixed solvent of acetonitrile and water, stirring for reaction for 4-8 h at 60-100 DEG C, and treating a reaction liquid obtained after the reaction is finished to prepare the benzil derivative shown in the formula II. The synthesis method has the advantages that the raw materials are cheap and easy to obtain, transition metal catalysis is not needed, the oxygen source is easy to obtain and environment-friendly, the reaction condition is mild, the target substrate can be synthesized efficiently, the universality of the functional group is good, and the operation is simple and convenient.
- -
-
Paragraph 0049-0052
(2020/02/07)
-
- Preparation method of 1,2-diketone derivative
-
The invention discloses a preparation method of a 1,2-diketone derivative. The method comprises the step of enabling a raw material 1,3-diketone derivative to react with a cheap and easily obtained industrial product 2,2,6,6-tetramethyl-1-piperidinyloxy under the catalysis of copper so as to obtain the product 1,2-diketone derivative. According to the preparation method, the 1,3-diketone derivative is used as an initiator, and the raw material is easy to obtain and wide in variety; by utilizing the preparation method, the obtained product types are varied, can be directly used, and can be used for other further reactions; in addition, the reagent dosage in the reaction is less, the pollution is reduced, and the production cost is lowered; moreover the reaction conditions are mild, the reaction operation and the after-treatment process are simple, the reaction time is short, the yield is high, and the preparation method is suitable for industrial production.
- -
-
Paragraph 0021
(2016/10/08)
-
- Synthesis of 1,2-Diketones via a Metal-Free, Visible-Light-Induced Aerobic Photooxidation of Alkynes
-
1,2-Diketones were synthesized by the oxidation of corresponding alkynes using air as the oxidant under metal-free conditions upon irradiation of blue light. A cheap and readily available organic dye, eosin Y, was used as the photocatalyst. For various substituents on the aryl ring, the reaction proceeded smoothly to give the dicarbonylation products in moderate to good yields. Some oxidation-sensitive groups, such as formyl and the carbon-carbon double bond, were tolerated under the developed reaction conditions.
- Liu, Xu,Cong, Tiantian,Liu, Ping,Sun, Peipei
-
p. 7256 - 7261
(2016/08/30)
-
- Covalent Assembly and Characterization of Nonsymmetrical Single-Molecule Nodes
-
The covalent linking of molecular building blocks on surfaces enables the construction of specific molecular nanostructures of well-defined shape. Molecular nodes linked to various entities play a key role in such networks, but represent a particular chal
- Nacci, Christophe,Viertel, Andreas,Hecht, Stefan,Grill, Leonhard
-
supporting information
p. 13724 - 13728
(2016/10/26)
-
- Copper-catalyzed base-accelerated direct oxidation of C-H bond to synthesize benzils, isatins, and quinoxalines with molecular oxygen as terminal oxidant
-
We describe herein an efficient and general copper (II)-catalyzed base-accelerated oxidation of the C-H bond to synthesize benzils and isatins. With similar oxidation system an efficient one-pot procedure for the synthesis of quinoxaline derivatives was realized. The two protocols feature using molecular oxygen as terminal oxidant, low catalyst loading, wide substrate scope, and high functional-group tolerance.
- Yu, Jing-Wen,Mao, Shuai,Wang, Yong-Qiang
-
supporting information
p. 1575 - 1580
(2015/03/14)
-
- Quinoxaline derivative, and light-emitting element, light-emitting device, and electronic device using the same
-
[Purpose] novel bipolar organic provides compounds in. Furthermore, carrier such a to provide a light-emitting element in. Furthermore, a low driving voltage and, power consumption small emitting element and a light-emission device, intended for to provide a. Furthermore, power consumption small electronic device, intended. [Constitution] provides quinoxaline derivatives represented to formula 1. Formula 1 In said formula 1, α 1 and α 2 the, independently, a carbon atoms forming a ring exhibits [...] 13 hereinafter, The Ar, carbon atoms forming a ring and aryl is 13 hereinafter, R 1 and R 6 the, independently, hydrogen atom, alkyl 1 to 6 carbon atoms, or a carbon atoms forming a ring 13 hereinafter and shows 0 aryl, R 2 to R 5 and R 7 to R 10 the, independently, hydrogen atom, of carbon number 1 to 6 alkyl, is phenyl substituted or unsubstituted, or substituted or unsubstituted. shows 0 ITO-glass substrate.
- -
-
-
- Selectfluor-Mediated Simultaneous Cleavage of C-O and C-C Bonds in α,β-Epoxy Ketones under Transition-Metal-Free Conditions: A Route to 1,2-Diketones
-
Selectfluor-mediated simultaneous cleavage of C-O and C-C bonds in α,β-epoxy ketones has been successfully achieved under transition-metal-free conditions. The reaction gives 1,2-diketone compounds in moderate to good yields involving a ring-opening/benzoyl rearrangement/C-C bond cleavage sequence under oxidative conditions.
- Wang, Heng,Ren, Shaobo,Zhang, Jian,Zhang, Wei,Liu, Yunkui
-
p. 6856 - 6863
(2015/10/06)
-
- Cobalt(II) catalyzed C(sp)-H bond functionalization of alkynes with phenyl hydrazines: Facile access to diaryl 1,2-diketones
-
A cobalt acetylacetonate catalyzed oxidative diketonation of alkynes via C(sp)-H bond functionalization has been described. The reaction involves a free-radical mechanism, wherein the phenyl radical formed from phenyl hydrazine couples with Co(ii) activated alkyne to produce 1,2-diketones. The reaction proceeds at room temperature in DMF with the use of Ag2O/air as the oxidizing system. The utility of the protocol for the synthesis of a series of imidazoles including a potent platelet aggregation inhibitor trifenagrel has been demonstrated.
- Bharate, Jaideep B.,Abbat, Sheenu,Sharma, Rohit,Bharatam, Prasad V.,Vishwakarma, Ram A.,Bharate, Sandip B.
-
p. 5235 - 5242
(2015/05/13)
-
- Visible-light-induced C=C bond cleavage of enaminones for the synthesis of 1,2-diketones and quinoxalines in sustainable medium
-
The C=C double bond cleavage of enaminones has been realized under ambient conditions through visible-light catalysis in the presence of Rose Bengal, which leads to the synthesis of a class of 1,2-diketones without using any metal catalyst. In addition, the one-pot synthesis of quinoxalines has also been achieved under identical photocatalytic conditions by making use of the in situ generated 1,2-diketones as intermediates.
- Cao, Shuo,Zhong, Shanshan,Xin, Luoting,Wan, Jie-Ping,Wen, Chengping
-
p. 1478 - 1482
(2015/06/24)
-
- Aminocatalytic cross-coupling approach via iminium ions to different C-C bonds
-
Given the attractive ability of iminium ions to functionalize molecules directly at ostensibly unreactive positions, the reactivity of iminium ions, in which an α CH2 group is replaced by C=O was explored. Background studies on the ability of such iminium cations to promote reactions via an iminium-catalyzed or iminium-equivalent pathway are apparently unavailable. Previously, tandem cross-coupling reactions were reported, in which an iminium ion undergoes nucleophilic 1,2-addition to give a putative three-component intermediate that abstracts a proton in situ and undergoes self-deamination followed by unprecedented DMSO/ aerobic oxidation to generate a-ketoamides. However, later it was observed that iminium ions can generate valuable α-ketoamides through simple aerobic oxidation. In all reactions, iminium ions were generated in situ by reaction of 2-oxoaldehydes with secondary amines.
- Mupparapu, Nagaraju,Battini, Narsaiah,Battula, Satyanarayana,Khan, Shahnawaz,Vishwakarma, Ram A.,Ahmed, Qazi Naveed
-
supporting information
p. 2954 - 2960
(2015/02/05)
-
- Oxidative cleavage of olefins by in situ-generated catalytic 3,4,5,6-tetramethyl-2-iodoxybenzoic acid/oxone
-
Oxidative cleavage of a variety of olefins to the corresponding ketones/carboxylic acids is shown to occur in a facile manner with 3,4,5,6-tetramethyl-2-iodobenzoic acid (TetMe-IA)/oxone. The simple methodology involves mere stirring of the olefin and catalytic amount (10 mol %) of TetMe-IA and oxone in acetonitrile-water mixture (1:1, v/v) at rt. The reaction mechanism involves initial dihydroxylation of the olefin with oxone, oxidative cleavage by the in situ-generated 3,4,5,6-tetramethyl-2-iodoxybenzoic acid (TetMe-IBX), and oxidation of the aldehyde functionality to the corresponding acid with oxone. Differences in the reactivities of electron-rich and electron-poor double bonds have been exploited to demonstrate chemoselective oxidative cleavage in substrates containing two double bonds.
- Moorthy, Jarugu Narasimha,Parida, Keshaba Nanda
-
p. 11431 - 11439
(2015/02/05)
-
- Efficient synthetic route to bisaryl ketones via copper-catalyzed C-C triple bonds cleavage
-
An efficient copper-catalyzed aerobic synthesis of bisaryl ketones from 1,2-diarylalkynes via C-C triple bonds cleavage has been demonstrated. The aniline compounds were found to be crucial in our conditions and a plausible mechanism was put forward. This reaction constitutes a new transformation from 1,2-diarylalkynes into bisaryl ketones with a practical, neutral, and mild synthetic approach.
- Li, Xiangguang,Huang, Wenzhong,Liang, Deqiang,Yuan, Lin,Ma, Yinhai,Gu, Lijun
-
p. 1045 - 1049
(2015/01/30)
-
- One-pot, two-step desymmetrization of symmetrical benzils catalyzed by the methylsulfinyl (dimsyl) anion
-
An operationally simple one-pot, two-step procedure for the desymmetrization of benzils is herein described. This consists in the chemoselective cross-benzoin reaction of symmetrical benzils with aromatic aldehydes catalyzed by the methyl sulfinyl (dimsyl) anion, followed by microwave-assisted oxidation of the resulting benzoylated benzoins with nitrate, avoiding the costly isolation procedure. Both electron-withdrawing and electron-donating substituents may be accommodated on the aromatic rings of the final unsymmetrical benzil. the Partner Organisations 2014.
- Ragno, Daniele,Bortolini, Olga,Giovannini, Pier Paolo,Massi, Alessandro,Pacifico, Salvatore,Zaghi, Anna
-
p. 5733 - 5744
(2014/07/22)
-
- Practical approach for preparation of unsymmetric benzils from β-ketoaldehydes
-
An efficient and practical method for the synthesis of unsymmetric benzils from readily available β-ketoaldehydes has been developed. Various unsymmetric 1,2-diaryldiketones bearing functional groups have been obtained in good to excellent yields under mild reaction conditions. A plausible mechanism was proposed, and α,α-dichloroketone was considered as the key intermediate. The generation of α,α-dichloroketones from β-ketoaldehydes may undergo the following steps: (1) oxidation by sodium hypochlorite, (2) decarboxylation, and (3) chlorination by Cl2 generated from sodium hypochlorite.
- Ruan, Libo,Shi, Min,Li, Nian,Ding, Xu,Yang, Fan,Tang, Jie
-
supporting information
p. 733 - 735
(2014/03/21)
-
- Asymmetric transfer hydrogenation of unsymmetrical benzils
-
In this paper, the asymmetric transfer hydrogenation of unsymmetrical benzils with m, p-substituents was conducted with a substrate/catalyst molar ratio of 100 at 40°C for 24 h to produce (S,S)-hydrobenzoins in good yields (76.2% to 97.1%) with high diastereomeric (syn/anti = 10.8 to 29.7/1) and enantiomeric purities (86.1%ee syn to 98.9%ee syn). Unfortunately, the unsymmetrical benzils with the o-substituents such as electron-donating (R = CH3, OCH3) and electron-withdrawing groups (R = F, Cl, CF3) resulted in poor yields (0% to 31.2%), even at 40°C for 72 h. These products had inefficient diastereoselectivities (syn/anti = 1.5 to 5.0/1) caused by steric effects. Furthermore, the results of a dynamic-kinetic study were used to propose a plausible reaction pathway of unsymmetrical benzil using 3-methoxy-1,2-diphenyl ethanedione as an example.
- Zhang, Hao,Feng, Dandan,Sheng, Haibo,Ma, Xuebing,Wan, Jinwei,Tang, Qian
-
p. 6417 - 6423
(2014/02/14)
-
- New cleavable photoinitiator architecture with huge molar extinction coefficients for polymerization in the 340-450 nm range.
-
A new Type I photoinitiator Tr-DMPA is described. It consists in three 2,2′-dimethoxy 2-phenyl acetophenone (DMPA) units grafted onto a truxene (Tr) scaffold. Compared to DMPA itself, the lowest electronic transition exhibits a ππ* character and the corre
- Tehfe, Mohamad-Ali,Dumur, Frederic,Graff, Bernadette,Clement, Jean-Louis,Gigmes, Didier,Morlet-Savary, Fabrice,Fouassier, Jean-Pierre,Lalevee, Jacques
-
p. 736 - 746
(2013/05/08)
-
- Copper-catalyzed oxidation of deoxybenzoins to benzils under aerobic conditions
-
A novel copper-catalyzed approach to benzils from readily available deoxybenzoins under neutral conditions using air as the oxidant has been developed. The reaction tolerates a variety of useful substituents including chloro, bromo, iodo, keto, ester, and cyano groups. Georg Thieme Verlag Stuttgart, New York.
- Cacchi, Sandro,Fabrizi, Giancarlo,Goggiamani, Antonella,Iazzetti, Antonia,Verdiglione, Rosanna
-
supporting information
p. 1701 - 1707
(2013/07/27)
-
- Catalyst-controlled highly selective coupling and oxygenation of olefins: A direct approach to alcohols, ketones, and diketones
-
Oxygen? That's radical! A method for the direct synthesis of substituted alcohols, ketones, and diketones through a catalyst-controlled highly chemoselective coupling and oxygenation of olefins has been developed. The method is simple and practical, can be switched by the selection of different catalysts, and employs molecular oxygen as both an oxidant and a reagent. Copyright
- Su, Yijin,Sun, Xiang,Wu, Guolin,Jiao, Ning
-
supporting information
p. 9808 - 9812
(2013/09/23)
-
- Facile and highly chemoselective synthesis of benzil derivatives via oxidation of stilbenes in an I2-H2O system
-
A facile and highly chemoselective protocol for the synthesis of benzil derivatives has been developed by oxidation of stilbenes in an I 2-H2O system under air. Notably, the method was applicable to 26 examples and provided up to 98% yield, avoiding the use of acid, metal catalysts and so on.
- Zeng, Xianghua,Miao, Chengxia,Wang, Shoufeng,Xia, Chungu,Sun, Wei
-
p. 9666 - 9669
(2013/09/02)
-
- A combination of copper(0) powder and selectfluor enables generation of cationic copper species for mild 1,2-dicarbonylation of alkynes
-
A combination of copper powder and Selectfluor permits the generation of cationic copper species that efficiently catalyze 1,2-dicarbonylation of alkynes under mild conditions with water and dioxygen as inexpensive and environmentally benign sources of oxygen. Georg Thieme Verlag Stuttgart New York.
- Zhang, Wenxia,Zhang, Jian,Liu, Yunkui,Xu, Zhenyuan
-
supporting information
p. 2709 - 2714
(2014/01/06)
-
- Ruthenium-catalyzed oxidation of alkynes to 1,2-diketones under room temperature and one-pot synthesis of quinoxalines
-
A ruthenium-catalyzed alkyne oxidation to 1,2-diketones using Oxone under room temperature is reported. Both substrate scope and mechanism were discussed. Notably, combination of the alkyne oxidation and condensation cyclization in one pot offers a very efficient and convenient entry into quinoxaline derivatives.
- Xu, Yuan,Wan, Xiaobing
-
supporting information
p. 642 - 645
(2013/02/23)
-
- Catalytic oxidation of silyl enol ethers to 1,2-diketones employing nitroxyl radicals
-
A novel and efficient method for the preparation of 1,2-diketones is reported. A series of -diketones were readily prepared by the nitroxyl-radical-catalyzed oxidation of silyl enol ethers using magnesium monoperoxyphthalate hexahydrate (MMPP6H) as the co-oxidant. Georg Thieme Verlag Stuttgart · New York.
- Hayashi, Masaki,Shibuya, Masatoshi,Iwabuchi, Yoshiharu
-
p. 1025 - 1030
(2012/06/04)
-
- Logic design and synthesis of quinoxalines via the integration of iodination/oxidation/cyclization sequences from ketones and 1,2-diamines
-
A novel protocol for the synthesis of quinoxalines has been developed from simple ketones and 1,2-diamines. This process underwent a logic approach to bis-substituted quinoxalines via a consecutive iodination/Kornblum oxidation/cyclization in the presence of I2/CuO/DMSO and to mono-substituted quinoxalines via an iodination/cyclization/aromatization in the presence of I2/CuO/K3PO4·3H 2O.
- Lian, Mi,Li, Qi,Zhu, Yanping,Yin, Guodong,Wu, Anxin
-
p. 9598 - 9605
(2012/11/07)
-
- One-pot synthesis of unsymmetrical benzils by oxidative coupling using selenium dioxide and p-toluenesulfonic acid monohydrate
-
The oxidative coupling of the α-carbon atom of aromatic ketones with unactivated arenes in the presence of selenium dioxide and p-toluenesulfonic acid monohydrate is described. A number of unsymmetrical benzils have been prepared in good yields (38-75 % with high regioselectivity. The generality and functional tolerance of this new protocol is demonstrated. The mechanistic pathway for the oxidative coupling reaction is also described. The reaction displays superiority in terms of minimization of steps with the C-C bond formation promoted by SeO2 and pTsOH·H2O. This method is advantageous as the reactants used as the solvent can be recovered. Copyright
- Rohman, Md. Rumum,Kharkongor, Icydora,Rajbangshi, Mantu,Mecadon, Hormi,Laloo, Badaker M.,Sahu, Priti R.,Kharbangar, Iadeishisha,Myrboh, Bekington
-
scheme or table
p. 320 - 328
(2012/02/04)
-
- One-pot synthesis of unsymmetrical benzils from aryl methyl ketones and arenes in the presence of selenous acid catalysed by p-toluenesulfonic acid monohydrate
-
A modified one-pot method for the synthesis of unsymmetrical and heteroaryl benzils from substituted acetophenones and unactivated or weakly activated arenes by the use of H2SeO3 and p-TsOH·H 2O as catalysts at 35°C is established. The present method is regioselective and avoids the use of p-TsOH·H2O in stoichiometric amount in the presence of H2SeO3 and afforded unsymmetrical benzils in good yields.
- Kharkongor, Icydora,Rohman, Md. Rumum,Myrboh, Bekington
-
experimental part
p. 2837 - 2841
(2012/07/27)
-
- DABCO-catalyzed oxidation of deoxybenzoins to benzils with air and one-pot synthesis of quinoxalines
-
Aerobic oxidation of deoxybenzoins could be efficiently catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO) with air as the sole oxidant to give the corresponding benzils in excellent yields. The effects of reaction conditions, such as different bases, temperature, time and solvent, on the yield of the product were investigated. Moreover, the process has been successfully extended to a one-pot synthesis of quinoxalines from benzyl ketones and aromatic 1,2-diamines. Georg Thieme Verlag Stuttgart New York.
- Qi, Chaorong,Jiang, Huanfeng,Huang, Liangbin,Chen, Zhengwang,Chen, Huoji
-
experimental part
p. 387 - 396
(2011/04/15)
-
- Iron-promoted C - C bond cleavage of 1,3-diketones: A route to 1,2-diketones under mild reaction conditions
-
A conceptual method for the preparation of 1,2-diketones is reported. The selective C - C bond cleavage of 1,3-diketones affords the 1,2-diketones in high yields under mild reaction conditions in air by the use of FeCl3 as the catalyst and tert-butyl nitrite (TBN) as the oxidant without the use of solvent. The possible reaction mechanism is discussed. This protocol provides an expeditious route to the useful 1,2-diketones.
- Huang, Lehao,Cheng, Kai,Yao, Bangben,Xie, Yongju,Zhang, Yuhong
-
experimental part
p. 5732 - 5737
(2011/08/22)
-
- Ruthenium-catalyzed oxidation of alkenes at room temperature: A practical and concise approach to α-diketones
-
Chemical equations presented. The catalytic oxidation of alkenes to α-diketones is unprecedented. A new oxidation of alkenes, catalyzed by a ruthenium complex, which allows an efficient route to α-diketones using TBHP as an oxidant is described. This methodology is highly functional group tolerant, is practically convenient, requires no additional ligand, and operates under mild conditions with short reaction times. Based upon experimental observations, a plausible mechanism is proposed.
- Chen, Shulin,Liu, Zhaojun,Shi, Erbo,Chen, Long,Wei, Wei,Li, Hong,Cheng, Yannan,Wan, Xiaobing
-
supporting information; experimental part
p. 2274 - 2277
(2011/06/27)
-
- Gold-catalyzed synthesis of benzil derivatives and α-keto imides via oxidation of alkynes
-
An efficient process based on the gold-catalyzed redox reaction has been developed to oxidize 1,2-diarylacetylene or ynamide to 1,2-diaryldiketone or α-keto imide respectively. This process can tolerate a variety of functional groups and affords 1,2-dicarbonyl compounds in excellent yields under mild reaction conditions.
- Xu, Cheng-Fu,Xu, Mei,Jia, Yi-Xia,Li, Chuan-Ying
-
p. 1556 - 1559
(2011/04/26)
-