- MAGNETIC AND MICELLAR EFFECTS IN PHOTOREACTIONS. (13)C NMR DETERMINATION OF SELECTIVE (13)C ENRICHMENT IN A DIBENZYL KETONE PHOTOPRODUCT.
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The photolysis of dibenzyl ketone (DBK) in micellar solution results in formation of 1-phenyl-4-methyl acetophenone (PMAP) as a minor product; quantitative integration of the (13)C NMR spectrum of PMAP produced by photolysis of DBK in micellar solution de
- Turro, N. J.,Chung, C.-J.,Lawler, R. G.,Smith, W. J.
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Read Online
- High-throughput photocapture approach for reaction discovery
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Modern organic reaction discovery and development relies on the rapid assessment of large arrays of hypothesis-driven experiments. The time-intensive nature of reaction analysis presents the greatest practical barrier for the execution of this iterative process that underpins the development of new bioactive agents. Toward addressing this critical bottleneck, we report herein a high-throughput analysis (HTA) method of reaction mixtures by photocapture on a 384-spot diazirine-terminated self-assembled monolayer, and selfassembled monolayers for matrix-assisted laser desorption/ionization mass spectrometry (SAMDI-MS) analysis. This analytical platform has been applied to the identification of a single-electron-promoted reductive coupling of acyl azolium species.
- Bayly, Alison A.,McDonald, Benjamin R.,Mrksich, Milan,Scheidt, Karl A.
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- H2O2-mediated room temperature synthesis of 2-arylacetophenones from arylhydrazines and vinyl azides in water
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An environmentally benign, cost-efficient and practical methodology for the room temperature synthesis of 2-arylacetophenones in water has been discovered. The facile and efficient transformation involves the oxidative radical addition of arylhydrazines with α-aryl vinyl azides in the presence of H2O2 (as a radical initiator) and PEG-800 (as a phase-transfer catalyst). From the viewpoint of green chemistry and organic synthesis, the present protocol is of great significance because of using cheap, non-toxic and readily available starting materials and reagents as well as amenability to gram-scale synthesis, which provides an attractive strategy to access 2-arylacetophenones.
- Luo, Mengqiang,Zhang, Yaohong,Fang, Ping,Li, Yan,Qi, Chenze,Li, Yong,Shen, Runpu,Cheng, Kai,Wang, Hai
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supporting information
p. 630 - 635
(2022/02/01)
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- Iron-Catalyzed Enantioselective Radical Carboazidation and Diazidation of α,β-Unsaturated Carbonyl Compounds
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Azidation of alkenes is an efficient protocol to synthesize organic azides which are important structural motifs in organic synthesis. Enantioselective radical azidation, as a useful strategy to install a C-N3 bond, remains challenging due to the inherently instability and unique structure of radicals. Here, we disclose an efficient enantioselective radical carboazidation and diazidation of α,β-unsaturated ketones and amides catalyzed by chiral N,N′-dioxide/Fe(OTf)2 complexes. An array of substituted alkenes was transformed to the corresponding α-azido carbonyl derivatives in good to excellent enantioselectivities, benefiting the preparation of chiral α-amino ketones, vicinal amino alcohols, and vicinal diamines. Control experiments and mechanistic studies proved the radical pathway in the reaction process. The DFT calculations showed that the azido transferred to the radical intermediate via an intramolecular five-membered transition state with the internal nitrogen of the Fe-N3 species.
- Dong, Shunxi,Feng, Xiaoming,He, Jun,Liu, Wen,Liu, Xiaohua,Pu, Maoping,Wu, Yun-Dong,Zhang, Tinghui
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supporting information
p. 11856 - 11863
(2021/08/16)
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- Palladium-catalyzed synthesis of α-aryl acetophenones from styryl ethers and aryl diazonium saltsviaregioselective Heck arylation at room temperature
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Preparation of α-aryl acetophenones from styryl ethers and aryldiazonium salts is described. The reaction is catalyzed by palladium acetate at room temperature in the absence of ligand and base. The developed method is highly attractive in terms of reaction conditions, substrate scope, functional group tolerance and yields. Synthetic applications of the present method are demonstrated by preparing α-aryl indoles and 3-aryl isocoumarin from styryl ethers.
- Kandasamy, Jeyakumar,Lee, Yong Rok,Singh, Adesh Kumar,Venkatesh, Rapelly
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supporting information
p. 7832 - 7837
(2021/09/28)
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- C-H Alkylation of Aldehydes by Merging TBADT Hydrogen Atom Transfer with Nickel Catalysis
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Catalyst controlled site-selective C-H functionalization is a challenging but powerful tool in organic synthesis. Polarity-matched and sterically controlled hydrogen atom transfer (HAT) provides an excellent opportunity for site-selective functionalization. As such, the dual Ni/photoredox system was successfully employed to generate acyl radicals from aldehydes via selective formyl C-H activation and subsequently cross-coupled to generate ketones, a ubiquitous structural motif present in the vast majority of natural and bioactive molecules. However, only a handful of examples that are constrained to the use of aryl halides are developed. Given the wide availability of amines, we developed a cross-coupling reaction via C-N bond cleavage using the economic nickel and TBADT catalyst for the first time. A range of alkyl and aryl aldehydes were cross-coupled with benzylic and allylic pyridinium salts to afford ketones with a broad spectrum of functional group tolerance. High regioselectivity toward formyl C-H bonds even in the presence of α-methylene carbonyl or α-amino/oxy methylene was obtained.
- Murugesan, Vetrivelan,Ganguly, Anirban,Karthika, Ardra,Rasappan, Ramesh
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p. 5389 - 5393
(2021/07/21)
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- Benzylic aroylation of toluenes with unactivated tertiary benzamides promoted by directed ortho-lithiation
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The deprotonative functionalization of toluenes, for their weak acidity, generally needs strong bases, thus leading to the requirement of harsh conditions and the generation of by-products. Direct nucleophilic acyl substitution reaction of amides with organometallic reagents could provide an ideal solution for ketone synthesis. However, the inert amides and highly reactive organometallic reagents bring great challenges for an efficient and selective synthetic approach. Herein, we reported an lithium diisopropylamide (LDA)-promoted benzylic aroylation of toluenes with unactivated tertiary benzamides, providing a direct and efficient synthesis of various aryl benzyl ketones. This process features a kinetic deprotonative functionalization of toluenes with a readily available base LDA. Mechanism studies revealed that the directed ortho-lithiation of the tertiary benzamide with LDA promoted the benzylic kinetic deprotonation of toluene and triggered the nucleophilic acyl substitution reaction with the amide. [Figure not available: see fulltext.].
- Bao, Can-Can,Luo, Yan-Long,Du, Hui-Zhen,Guan, Bing-Tao
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p. 1349 - 1354
(2021/07/12)
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- Ring size and nothing else matters: unusual regioselectivity of alkyne hydration by NHC gold(i) complexes
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We have investigated the role of ring sizes and substituents in NHC ligands in some (NHC)Au(i) complexes in the hydration of internal alkynes. Despite the fact that using (NHC)Au(i) complexes in the hydration of diarylacetylenes leads to Markovnikov-type products, the precise tuning of ligands allows changing the regioselectivity in arylalkylacetylene hydration to the anti-Markovnikov-type.
- Ageshina, Alexandra A.,Asachenko, Andrey F.,Chesnokov, Gleb A.,Minaeva, Lidiya I.,Nechaev, Mikhail S.,Philippova, Anna N.,Rzhevskiy, Sergey A.,Topchiy, Maxim A.
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supporting information
p. 5686 - 5689
(2021/06/16)
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- Gold-Catalyzed [3+2]-Annulations of α-Aryl Diazoketones with the Tetrasubstituted Alkenes of Cyclopentadienes: High Stereoselectivity and Enantioselectivity
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This work reports gold-catalyzed [3+2]-annulations of α-diazo ketones with highly substituted cyclopentadienes, affording bicyclic 2,3-dihydrofurans with high regio- and stereoselectivity. The reactions highlights the first success of tetrasubstituted alkenes to undergo [3+2]-annulations with α-diazo carbonyls. The enantioselective annulations are also achieved with high enantioselectivity using chiral forms of gold and phosphoric acid. Our mechanistic analysis supports that cyclopentadienes serve as nucleophiles to attack gold carbenes at the more substituted alkenes, yielding gold enolates that complex with chiral phosphoric acid to enhance the enantioselectivity.
- Chen, Ching-Nung,Cheng, Wei-Min,Wang, Jian-Kai,Chao, Tzu-Hsuan,Cheng, Mu-Jeng,Liu, Rai-Shung
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supporting information
p. 4479 - 4484
(2021/01/21)
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- Visible-Light-Promoted [3 + 2] Cycloaddition of 2H-Azirines with Quinones: Access to Substituted Benzo[f]isoindole-4,9-diones
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A visible-light-promoteded [3 + 2] cycloaddition reaction of 2H-azirines with quinones has been developed under mild reaction conditions. The reaction provides a general and efficient strategy for the synthesis of the benzo[f]isoindole-4,9-diones scaffold
- Li, Lei,Liu, Chuang,Sun, Ran,Wang, He,Wang, Lijia,Wang, Xin,Zhou, Ming-Dong
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supporting information
(2022/01/22)
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- Aerobic oxygenation of α-methylene ketones under visible-light catalysed by a CeNi3complex with a macrocyclic tris(salen)-ligand
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A hetero-tetranuclear CeNi3 complex with a macrocyclic ligand catalysed the aerobic oxygenation of a methylene group adjacent to a carbonyl group under visible-light radiation to produce the corresponding α-diketones. The visible-light induced homolysis of the Ce-O bond of a bis(enolate) intermediate is proposed prior to aerobic oxygenation.
- Fujiwara, Sakiko,Kon, Yoshihiro,Mashima, Kazushi,Nagae, Haruki,Okuda, Jun,Sakamoto, Kazutaka,Sato, Kazuhiko,Schindler, Tobias
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supporting information
p. 11169 - 11172
(2021/11/04)
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- Ruthenium(II)-Catalyzed Cross-Coupling of Benzoyl Formic Acids with Toluenes: Synthesis of 2-Phenylacetophenones
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Herein, we report a direct method to synthesize 2-phenylacetophenone through a ruthenium(II)-catalyzed cross-coupling reaction between acyl and benzyl radical. The various derivatives of 2-phenylacetophenone were prepared easily in moderate to good yields. These reactions provide a straightforward pathway to synthesize a variety of ketones bearing various functional groups.
- Chen, Yujie,Dai, Chenyang,Huang, Zhibin,Jiang, Yaqiqi,Shu, Sai,Yang, Shan,Zhao, Yingsheng
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p. 2955 - 2961
(2021/07/22)
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- Oxaprozin Analogues as Selective RXR Agonists with Superior Properties and Pharmacokinetics
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The retinoid X receptors (RXR) are ligand-activated transcription factors involved in multiple regulatory networks as universal heterodimer partners for nuclear receptors. Despite their high therapeutic potential in many pathologies, targeting of RXR has only been exploited in cancer treatment as the currently available RXR agonists suffer from exceptional lipophilicity, poor pharmacokinetics (PK), and adverse effects. Aiming to overcome the limitations and to provide improved RXR ligands, we developed a new potent RXR ligand chemotype based on the nonsteroidal anti-inflammatory drug oxaprozin. Systematic structure-activity relationship analysis enabled structural optimization toward low nanomolar potency similar to the well-established rexinoids. Cocrystal structures of the most active derivatives demonstrated orthosteric binding, and in vivo profiling revealed superior PK properties compared to current RXR agonists. The optimized compounds were highly selective for RXR activation and induced RXR-regulated gene expression in native cellular and in vivo settings suggesting them as excellent chemical tools to further explore the therapeutic potential of RXR.
- Schierle, Simone,Chaikuad, Apirat,Lillich, Felix F.,Ni, Xiaomin,Woltersdorf, Stefano,Schallmayer, Espen,Renelt, Beatrice,Ronchetti, Riccardo,Knapp, Stefan,Proschak, Ewgenij,Merk, Daniel
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supporting information
p. 5123 - 5136
(2021/05/04)
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- The organocatalytic enantiodivergent fluorination of β-ketodiaryl-phosphine oxides for the construction of carbon-fluorine quaternary stereocenters
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Commercially available cinchona alkaloids that can catalyze the enantiodivergent fluorination of β-ketodiarylphosphine oxides were developed to construct carbon-fluorine quaternary stereocenters. This protocol features a wide scope of substrates and excellent enantioselectivities, and it is scalable.
- Xie, Shaolei,He, Zhi-Juan,Zhang, Ling-Hui,Huang, Bo-Lun,Chen, Xiao-Wei,Zhan, Zong-Song,Zhang, Fu-Min
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supporting information
p. 2069 - 2072
(2021/03/01)
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- Combined Theoretical and Experimental Studies Unravel Multiple Pathways to Convergent Asymmetric Hydrogenation of Enamides
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We present a highly efficient convergent asymmetric hydrogenation of E/Z mixtures of enamides catalyzed by N,P-iridium complexes supported by mechanistic studies. It was found that reduction of the olefinic isomers (E and Z geometries) produces chiral amides with the same absolute configuration (enantioconvergent hydrogenation). This allowed the hydrogenation of a wide range of E/Z mixtures of trisubstituted enamides with excellent enantioselectivity (up to 99% ee). A detailed mechanistic study using deuterium labeling and kinetic experiments revealed two different pathways for the observed enantioconvergence. For α-aryl enamides, fast isomerization of the double bond takes place, and the overall process results in kinetic resolution of the two isomers. For α-alkyl enamides, no double bond isomerization is detected, and competition experiments suggested that substrate chelation is responsible for the enantioconvergent stereochemical outcome. DFT calculations were performed to predict the correct absolute configuration of the products and strengthen the proposed mechanism of the iridium-catalyzed isomerization pathway.
- Yang, Jianping,Massaro, Luca,Krajangsri, Suppachai,Singh, Thishana,Su, Hao,Silvi, Emanuele,Ponra, Sudipta,Eriksson, Lars,Ahlquist, M?rten S. G.,Andersson, Pher G.
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supporting information
p. 21594 - 21603
(2021/12/27)
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- Blue Light Promoted Difluoroalkylation of Aryl Ketones: Synthesis of Quaternary Alkyl Difluorides and Tetrasubstituted Monofluoroalkenes
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A facile and cost-effective method for the preparation of fluoroalkylated compounds has been described by the direct photoexcitation of halofluoroalkanes with blue light absorptivity, enabling the difluoroalkylation of aryl ketones. The methodology has provided an efficient, mild, and catalyst-free synthetic method for quaternary difluoroalkylated arenes and tetrasubstituted monofluoroalkenes.
- Li, Kangkui,Chen, Jingchao,Yang, Chunhui,Zhang, Keyang,Pan, Chunxiang,Fan, Baomin,Fan, Baomin
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supporting information
p. 4261 - 4265
(2020/06/04)
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- Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids
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As a key element in the construction of complex organic scaffolds, the formation of C?C bonds remains a challenge in the field of synthetic organic chemistry. Recent advancements in single-electron chemistry have enabled new methods for the formation of various C?C bonds. Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium in situ followed by a radical–radical coupling was made possible merging N-heterocyclic carbene (NHC) and photoredox catalysis. The utility of this protocol in synthesis was showcased in the late-stage functionalization of a variety of pharmaceutical compounds. Preliminary investigations using chiral NHCs demonstrate that enantioselectivity can be achieved, showcasing the advantages of this protocol over alternative methodologies.
- Betori, Rick C.,Davies, Anna V.,Fitzpatrick, Keegan P.,Scheidt, Karl A.
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supporting information
p. 9143 - 9148
(2020/03/30)
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- A copper-catalyzed insertion of sulfur dioxide: Via radical coupling
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A copper-catalyzed three-component reaction of O-acyl oximes, DABCO·(SO2)2, and 2H-azirines under mild conditions has been achieved. This protocol provides an efficient route for the construction of various tetrasubstituted β-sulfonyl N-unprotected enamines in moderate to good yields with excellent stereoselectivity and regioselectivity. Notably, this method represents a rare example of 2H-azirines as useful synthons for β-functionalized N-unprotected enamines. Preliminary mechanistic studies indicate that the reaction proceeds through coupling of a sulfonyl radical and α-carbon radical via copper-catalyzed ring-opening C-C bond cleavage of O-acyl oxime and C-N bond cleavage of 2H-azirine with the insertion of sulfur dioxide.
- Zhang, Jun,Yang, Min,Liu, Jin-Biao,He, Fu-Sheng,Wu, Jie
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supporting information
p. 3225 - 3228
(2020/03/23)
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- Preparation method of diabetes-treating medicine, namely ipragliflozin or derivative thereof
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The invention provides a preparation method of a diabetes-treating medicine, namely ipragliflozin or a derivative thereof. According to the preparation method, alpha-O-alkenyl sulfone is used as an electrophilic reagent for the Suzuki-Miyaura coupling reaction; the reaction raw material alpha-O-alkenyl sulfone is simple to prepare and stable in structure, and can overcome the defects of instability, preparation difficulty and the like when organic halide and sulfonic acid are used as electrophilic reagents for the Suzuki-Miyaura coupling reaction. Meanwhile, the reaction are mild in reaction conditions, compatible with a wide range of heterocyclic rings and various functional groups, high in yield and capable of realizing large-scale process production. Since alpha-O-alkenyl sulfone is used as the electrophilic reagent for the Suzuki-Miyaura coupling reaction, high-yield generation of aryl glucoside and open-chain alkenyl ether can be realized, medicines for treating type 2 diabetes mellitus, namely ipragliflozin and 2-deoxyipragliflozin can also be prepared, and the application scope of the preparation method is wide.
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Paragraph 0342; 0344-0346
(2020/11/01)
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- Suzuki-Miyaura coupling reaction using alpha-O-alkenyl sulfone as electrophilic reagent and application thereof
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The invention provides a Suzuki-Miyaura coupling reaction using alpha-O-alkenyl sulfone as an electrophilic reagent. The reaction comprises the following steps: weighing alpha-O-alkenyl sulfone, an organic boron reagent, a ligand, an alkali and a catalyst, and carrying out reacting in a solvent. The invention also provides application of the coupling reaction. According to the invention, alpha-O-alkenyl sulfone is used as the electrophilic reagent for the Suzuki-Miyaura coupling reaction, and the reaction raw material alpha-O-alkenyl sulfone is simple to prepare and stable in structure, and can overcome the defects of instability, preparation difficulty and the like when organic halide and sulfonic acid are used as electrophilic reagents for the Suzuki-Miyaura coupling reaction. Meanwhile,the reaction are mild in reaction conditions, compatible with a wide range of heterocyclic rings and various functional groups, high in yield and capable of realizing large-scale process production.Since the alpha-O-alkenyl sulfone is used as the electrophilic reagent for the Suzuki-Miyaura coupling reaction, high-yield generation of aryl glucoside and open-chain alkenyl ether can be realized, medicines for treating type 2 diabetes mellitus, namely ipragliflozin and 2-deoxyipragliflozin can also be prepared, and the application scope of the reaction is wide.
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Paragraph 0379-0383
(2020/11/01)
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- Synthesis of unsymmetrical ketones by applying visible-light benzophenone/nickel dual catalysis for direct benzylic acylation
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Herein, we report a dual catalytic system for the direct benzylic C-H acylation reaction furnishing a variety of unsymmetrical ketones. A benzophenone-derived photosensitizer combined with a nickel catalyst has been established as the catalytic system. Both acid chlorides and anhydrides are able to acylate the benzylic position of toluene and other methylbenzenes. The method offers a valuable alternative to late transition metal catalyzed C-H acylation reactions.
- Krach, Patricia E.,Dewanji, Abhishek,Yuan, Tingting,Rueping, Magnus
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supporting information
p. 6082 - 6085
(2020/06/18)
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- Chemoselective Synthesis of Aryl Ketones from Amides and Grignard Reagents via C(O)-N Bond Cleavage under Catalyst-Free Conditions
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Conversion of a wide range of N-Boc amides to aryl ketones was achieved with Grignard reagents via chemoselective C(O)-N bond cleavage. The reactions proceeded under catalyst-free conditions with different aryl, alkyl, and alkynyl Grignard reagents. α-Ketoamide was successfully converted to aryl diketones, while α,β-unsaturated amide underwent 1,4-addition followed by C(O)-N bond cleavage to provide diaryl propiophenones. N-Boc amides displayed higher reactivity than Weinreb amides with Grignard reagents. A broad substrate scope, excellent yields, and quick conversion are important features of this methodology.
- Sureshbabu, Popuri,Azeez, Sadaf,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
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p. 11823 - 11838
(2019/10/02)
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- Ni-Catalyzed Suzuki-Miyaura Cross-Coupling of α-Oxo-vinylsulfones to Prepare C-Aryl Glycals and Acyclic Vinyl Ethers
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We demonstrate that readily available and bench-stable α-oxo-vinylsulfones are competent electrophiles in Ni-catalyzed Suzuki-Miyaura cross-coupling reactions. The C-sulfone bond in the α-oxo-vinylsulfone motif is cleaved chemoselectively in these reactions, furnishing C-aryl glycals or acyclic vinyl ethers in high yields. These reactions proceed under mild conditions and tolerate a remarkable scope of heterocycles and functional groups. Preliminary mechanistic studies revealed the importance of an α-heteroatom in facilitating these transformations.
- Gong, Liang,Sun, Hong-Bao,Deng, Li-Fan,Zhang, Xia,Liu, Jie,Yang, Shengyong,Niu, Dawen
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supporting information
(2019/05/22)
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- Ni-Catalyzed Suzuki-Miyaura Cross-Coupling of α-Oxo-vinylsulfones to Prepare C-Aryl Glycals and Acyclic Vinyl Ethers
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We demonstrate that readily available and bench-stable α-oxo-vinylsulfones are competent electrophiles in Ni-catalyzed Suzuki-Miyaura cross-coupling reactions. The C-sulfone bond in the α-oxo-vinylsulfone motif is cleaved chemoselectively in these reactions, furnishing C-aryl glycals or acyclic vinyl ethers in high yields. These reactions proceed under mild conditions and tolerate a remarkable scope of heterocycles and functional groups. Preliminary mechanistic studies revealed the importance of an α-heteroatom in facilitating these transformations.
- Gong, Liang,Sun, Hong-Bao,Deng, Li-Fan,Zhang, Xia,Liu, Jie,Yang, Shengyong,Niu, Dawen
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supporting information
p. 7680 - 7686
(2019/05/22)
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- NCN-Pincer palladium complexes immobilized on MCM-41 molecular sieve: Application in Α-arylation reactions
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Aromatic para-functionalized NCN pincer compounds tethered to a triethoxysilane moiety through a carbamate linkage were immobilized on ordered MCM-41 molecular sieve using a grafting process. The acquired immobilized organometallic pincer complexes were synthesized in high yields with no complex degradation and characterized by IR sprctroscopy, elemental content analysis. Nitrogen physisorption, XRD and TEM revealed that the mesoporous structure was retained during the immobilization process. The hybrid materials were applied as Lewis acid catalysts in the α-arylation reaction between aryl ketones and aryl halides, with the yield up to 95%. The tendency to form mono- or di-arylated products was investigated and the catalyst could be easily recovered and reused in five runs without a significant loss in its activity.
- Kai, Wang,Qian, Hua,Liu, Dabin,Ye, Zhiwen
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- Ag2CO3-mediated direct functionalization of alkyl nitriles: Facile synthesis of γ-ketonitriles through nitrile alkylation of enol acetates
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Direct C(sp3)-H functionalization of alkyl nitriles is a low toxic and facile route to nitrile-containing compounds. In this research, the Ag2CO3-mediated nitrile methylenation of enol acetates is developed to prepare γ-ketonitriles through the direct C(sp3)-H oxidative functionalization of acetonitrile. A radical pathway is proposed, and acetonitrile serves both as solvent and CN-containing radical source.
- Cheng, Pi,Wang, Wei,Wang, Lin,Zeng, Jianguo,Reiser, Oliver,Liang, Yun
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supporting information
p. 1408 - 1412
(2019/05/06)
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- Reaction of arynes with trifluoroacetylated β-diketones: Novel formation of isocoumarins and phenanthrenes
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Polysubstituted isocoumarins were synthesized by the reaction of substituted 2-(trimethylsilyl)aryl triflates with trifluoromethylated β-diketones in the presence of CsF. The reaction proceeded through carbon-carbon bond insertion of aryne and intramolecular cyclization to form intermediates of alcohol anions, which extruded trifluoromethyl anion to afford isocoumarins. By using CuBr as a catalyst, 2 eq. of aryne reacted with β-diketones to afford phenanthrenes and 1,2-diarylethanones. Although reaction of 2-(trimethylsilyl)phenyl triflate with 1,1,1-trifluoro-4′-methylbenzoylacetone in the presence of CsF gave 3-(4′-methylphenyl)isocoumarin in 67% yield, addition of 0.2 eq. of CuCN resulted in the formation of 9-(4-methylbenzoyl)-10-trifluoromethylphenanthrene in 35% yield.
- Okuma, Kentaro,Tanabe, Yukiko,Fukami, Takuto,Ishibashi, Yuto
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- Coupling of Sulfoxonium Ylides with Arynes: A Direct Synthesis of Pro-Chiral Aryl Ketosulfoxonium Ylides and Its Application in the Preparation of α-Aryl Ketones
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A general, mild, and versatile synthesis of the challenging α-aryl-β-ketosulfoxonium ylides has been developed for the first time, substituting traditional methods starting from diazo compounds. The arylation of easily accessible β-ketosulfoxonium ylides using aryne chemistry allowed the preparation of a large scope of the pro-chiral ylides in very good yields (40 examples; up to 85%). As applications, these ylides were smoothly converted into α-aryl ketones after desulfurization in good yields (up to 98%) as well as in other important derivatives.
- Talero, Alexánder Garay,Martins, Bruna Sim?es,Burtoloso, Antonio C. B.
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p. 7206 - 7211
(2018/11/23)
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- Mn/Cu catalyzed addition of arylboronic acid to nitriles: Direct synthesis of arylketones
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A direct and efficient synthesis of arylketones via arylboronic acid addition to nitriles in presence of inexpensive Mn/Cu catalytic system is reported. The use of non-precious Mn and Cu salts has been found to be highly advantageous both in terms of accessibility as well as cost effectiveness. A series of arylboronic acids as well as nitriles were used to synthesize a variety of symmetrical and unsymmetrical arylketones. Based on the literature studies, the reaction mechanism is anticipated to go through an aryl radical intermediate which reacted with the copper activated nitrile to give the desired arylketones after the hydrolysis of the imine intermediate.
- Moustafa, Dina,Sweet, Chelsea,Lim, Hyun,Calalpa, Brenda,Kaur, Parminder
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p. 3816 - 3820
(2018/09/18)
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- Photo induced alkyne hydration reactions mediated by a water soluble, reusable Rhodium (I) catalyst
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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.
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- Metal/catalyst/reagent free hydration of alkynes up to gram scale under temperature and pressure controlled condition
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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.
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p. 2075 - 2078
(2018/05/04)
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- Silver/NBS-Catalyzed Synthesis of α-Alkylated Aryl Ketones from Internal Alkynes and Benzyl Alcohols via Ether Intermediates
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The silver hexafluoroantimonate/N-bromosuccinimide (NBS)-catalyzed synthesis of α-alkylated aryl ketones with a tertiary carbon center from internal alkynes and benzyl alcohols is reported. This reaction proceeds via the etherification of benzyl alcohols with an in situ generated benzyl bromide, formed by the reaction of benzyl alcohol with a catalytic amount of NBS and AgSbF6. Ag-catalyzed C-O cleavage of the ether leads to a tolyl radical, which undergoes addition to the alkyne, ultimately leading to the α-alkylated aryl ketone products.
- Chun, Supill,Chung, Young Keun
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supporting information
p. 5583 - 5586
(2018/09/21)
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- Metal-free synthesis of ketones by visible-light induced aerobic oxidative radical addition of aryl hydrazines to alkenes
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A green and cost-effective method has been developed for the conversion of alkenes to ketones under metal-free conditions. The reaction involves the oxidative addition of alkenes with aryl radicals, which are generated by visible-light induced aerobic oxidation of arylhydrazines. The key features of this reaction include broad substrate scope, readily available reagents and amenability to gram-scale synthesis.
- Ding, Ya,Zhang, Wenkai,Li, Hao,Meng, Yunge,Zhang, Te,Chen, Qiu-Yun,Zhu, Chunyin
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supporting information
p. 2941 - 2944
(2017/07/24)
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- COMPOUNDS
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The present invention describes non-cyclic enaminoketone compounds and their applications relating to absorption electromagnetic energy, in particular UV radiation.
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- Base-mediated insertion reaction of alkynes into carbon-carbon σ-bonds of ethanones: synthesis of hydroxydienone and chromone derivatives
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Transition-metal free insertions of alkynes into carbon-carbon σ-bonds of ethanones have been reported. These tandem reactions offer an efficient synthesis of hydroxydienones and multi-substituted chromones. This is the first example of base-promoted insertion reactions of isolated carbon-carbon triple bonds into carbon-carbon σ-bonds with active methylene compounds bearing only one electron-withdrawing group.
- Zhang, Fangfang,Yao, Qiyi,Yuan, Yang,Xu, Murong,Kong, Lingkai,Li, Yanzhong
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supporting information
p. 2497 - 2500
(2017/04/03)
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- Novel bisamide palladium(II) pincer complexes: effective catalysts in α-arylation of ketones
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Three benzenedicarboxamide ligands (L) were designed and synthesized, and each was used to prepare a palladium(II) complex Pd(L)Br and Pd(L)(OAc). These NCN pincer complexes were used to catalyze the α-arylations of a variety of ketones with aryl chlorides or bromides in various solvents, and moderate-to-excellent yields were obtained (up to 95%). Further research showed that unactivated and sterically hindered aryl halides and ketones are also suitable substrates for the synthesis of α-arylation. Graphical Abstract: [Figure not available: see fulltext.].
- Kai, Wang,Liu, Dabin,Qian, Hua,Ye, Zhiwen
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p. 443 - 450
(2017/07/12)
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- Selective Metal-Free Deoxygenation of Unsymmetrical 1,2-Dicarbonyl Compounds by Chlorotrimethylsilane and Sodium Iodide
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For the first time, the combination of chlorotrimethylsilane with NaI is used as a selective reducting system toward 1,2-diketones. This combination is successfully evaluated with several unsymmetrically benzil derivatives, which are reduced in good yield
- Yuan, Ling-Zhi,Renko, Dolor,Khelifi, Ilhem,Provot, Olivier,Brion, Jean-Daniel,Hamze, Abdallah,Alami, Mouad
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supporting information
p. 3238 - 3241
(2016/07/14)
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- Microwave Heated Continuous Flow Palladium(II)-Catalyzed Desulfitative Synthesis of Aryl Ketones
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A protocol for Pd(II)-catalyzed desulfitative synthesis of aryl ketones from sodium aryl sulfinates and nitriles in continuous flow has been developed. The reactions proceed with microwave heating using microwave transparent tube reactors, affording the desired aryl ketones in fair to good yields. Microwave transparent aluminum oxide reactors were identified as a safe and thermostable alternative to borosilicate glass reactors.
- Skillinghaug, Bobo,Rydfjord, Jonas,S?vmarker, Jonas,Larhed, Mats
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supporting information
p. 2005 - 2011
(2017/02/10)
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- Ascorbic Acid Promoted Oxidative Arylation of Vinyl Arenes to 2-Aryl Acetophenones without Irradiation at Room Temperature under Aerobic Conditions
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A convenient and general protocol for oxidative arylation of vinyl arenes by aryl radicals generated in situ from arene diazonium fluoroborates promoted by ascorbic acid in air at room temperature has been developed in the absence of any additive and visible light irradiation. A series of diversely substituted 2-aryl acetophenones have been obtained in good yields by this procedure.
- Majhi, Biju,Kundu, Debasish,Ranu, Brindaban C.
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supporting information
p. 7739 - 7745
(2015/08/18)
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- An expedient route to heterocycles through α-arylation of ketones and arylamides by microwave induced thermal SRN1 reactions
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Microwave irradiation promotes a quick aromatic nucleophilic substitution by a thermally induced electron transfer process to form new C-C bonds by the coupling of aryl radicals and enolate nucleophiles. Diverse 2-aryl-1- phenylethanones can be prepared by the direct α-arylation of acetophenone with different haloarenes. The ketone enolate anion is generated by deprotonation with tBuOK in DMSO and the reaction is carried out in a closed microwave vessel at 70-100°C for 10 min. This simple procedure also allows the synthesis of deoxybenzoin and indole heterocycle derivatives by inter- or intra-molecular ring closure reactions, with moderate to excellent substitution yields. This journal is the Partner Organisations 2014.
- Soria-Castro, Silvia M.,Caminos, Daniel A.,Penenory, Alicia B.
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p. 17490 - 17497
(2014/05/06)
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- Palladium(II)-catalyzed desulfitative synthesis of aryl ketones from sodium arylsulfinates and nitriles: Scope, limitations, and mechanistic studies
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A fast and efficient protocol for the palladium(II)-catalyzed production of aryl ketones from sodium arylsulfinates and various organic nitriles under controlled microwave irradiation has been developed. The wide scope of the reaction has been demonstrated by combining 14 sodium arylsulfinates and 21 nitriles to give 55 examples of aryl ketones. One additional example illustrated that, through the choice of the nitrile reactant, benzofurans are also accessible. The reaction mechanism was investigated by electrospray ionization mass spectrometry and DFT calculations. The desulfitative synthesis of aryl ketones from nitriles was also compared to the corresponding transformation starting from benzoic acids. Comparison of the energy profiles indicates that the free energy requirement for decarboxylation of 2,6-dimethoxybenzoic acid and especially benzoic acid is higher than the corresponding desulfitative process for generating the key aryl palladium intermediate. The palladium(II) intermediates detected by ESI-MS and the DFT calculations provide a detailed understanding of the catalytic cycle. (Figure Presented).
- Skillinghaug, Bobo,Sk?ld, Christian,Rydfjord, Jonas,Svensson, Fredrik,Behrends, Malte,S?vmarker, Jonas,Sj?berg, Per J. R.,Larhed, Mats
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p. 12018 - 12032
(2015/01/16)
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- An efficient simple one-pot synthesis, characterization and structural studies of some 1,2,3,5-tetraarylpentane-1,5-diones
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A series of 1,2,3,5-tetraarylpentane-1,5-diones (9-23) were synthesised by simple one-pot method and characterized by FT-IR, 1H NMR, 13C NMR and mass spectral techniques. The structure of 3-(4-fluorophenyl)-1,2,5-triphenylpentane-1,5-dione (10) was determined by single crystal X-ray diffraction analysis. The compound 10 crystallize in monoclinic crystal system, in C2/c space group. The torsional angle between the two keto groups was found to be -29.50. The C(23)C(22)C(15)C(8)C(7) chain is almost planar with "W" conformation and observed maximum deviation is 0.122 ? for C(15) from the C(23)/C(22)/C(15)/C(8)/C(7) plane.
- Senthilkumar,Neelakandan,Manikandan
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- Catalyst-controlled highly selective coupling and oxygenation of olefins: A direct approach to alcohols, ketones, and diketones
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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
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supporting information
p. 9808 - 9812
(2013/09/23)
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- Diarylated ethanones from Mo(CO)6-mediated and microwave-assisted palladium-catalysed carbonylative Negishi cross-couplings
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Two protocols for palladium-catalysed carbonylative Negishi cross-couplings were developed for aryl iodides and aryl bromides. The two main breakthroughs were that molybdenum hexacarbonyl [Mo(CO)6] could be used as a solid in situ source of CO, and that controlled microwave irraditaion could be used for heating. Consequently, the reactions were safe (in contrast to when CO gas was used) and fast (in comparison to when conventional heating was used). The carbonylative cross-coupling reactions were carried out using commercially available benzylzinc bromide in closed vials (90-120°C for 0.5-1 h) to give a set of diarylated ethanones, a common pharmacophore found in several pharmaceuticals, in moderate to high isolated yields (47-84 %). The mild three-component carbonylation protocol presented here is operationally simple, safe, and rapid, and the formation of the carbonylative Negishi cross-coupling product is favoured over the product of Negishi cross-coupling. Copyright
- Motwani, Hitesh V.,Larhed, Mats
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supporting information
p. 4729 - 4733
(2013/08/23)
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- Catalytic decarboxylative cross-ketonisation of aryl- and alkylcarboxylic acids using iron catalysts
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In the presence of catalytic amounts of magnetite nanopowder, mixtures of aromatic and aliphatic carboxylic acids are converted selectively into the corresponding aryl alkyl ketones. As by-products, only carbon dioxide and water are released. This catalytic cross-ketonisation allows the regioselective acylation of aromatic systems and, thus, represents a sustainable alternative to Friedel-Crafts acylations.
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Page/Page column 3-4
(2012/07/03)
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- Synthesis, spectral studies and biological evaluation of a novel series of 2-substituted-5,6-diarylsubstituted imidazo(2,1-b)-1,3, 4-thiadiazole derivatives as possible anti-tubercular agents
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A novel series of 18 analogs of 2-substituted-5,6- diarylsubstituted imidazo(2,1-b)-1,3,4-thiadiazole 6a-r have been synthesized by the reaction of 2-amino-5-substituted- 1,3,4-thiadiazoles 5a-d and an appropriately substituted a-bromo-1,2-(p-substituted)diaryl-1-ethanones 4a-e. Structures of these compounds were established by physiochemical, elemental analysis and spectral data. All the title compounds were tested for their in-vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv using Alamar Blue susceptibility test and the activity expressed as the minimum inhibitory concentration (MIC) in lg/ml. Among synthesized compounds, compound 6h (MIC = 1.25 μg/ml) exhibited excellent anti-tubercular activity with respect to other synthesized compounds and reference drugs. Compounds 6c, 6f, and6g have also displayed an encouraging anti-tubercular activity profile. Further, some title compounds were also assessed for their cytotoxic activity (IC 50) against in a mammalian Vero cell line using MTT assay. The results reveal that these compounds exhibit anti-tubercular activity at non-cytotoxic concentrations. Springer Science+Business Media, LLC 2011.
- Palkar, Mahesh B.,Noolvi, Malleshappa N.,Maddi, Veeresh S.,Ghatole, Mangala,Nargund, Laxmivenkat G.
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experimental part
p. 1313 - 1321
(2012/08/07)
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- Nickel-catalyzed Kumada reaction of tosylalkanes with Grignard reagents to produce alkenes and modified arylketones
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Open a new door: The first example of alkene synthesis from alkyl electrophiles with Grignard reagents using the Kumada cross-coupling reaction strategy is reported. This method opens a new door for the Kumada cross-coupling reaction, allowing alkenes to be prepared from the reaction of tosylalkanes with Grignard reagents. Copyright
- Wu, Ji-Cheng,Gong, Lu-Bing,Xia, Yuanzhi,Song, Ren-Jie,Xie, Ye-Xiang,Li, Jin-Heng
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supporting information
p. 9909 - 9913
(2012/10/30)
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- Palladium-catalyzed carbonylative negishi-type coupling of aryl iodides with benzyl chlorides
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Do the competition: The synthesis of 1,2-diarylethanones has been accomplished using the palladium-catalyzed coupling of aryl iodides and CO/benzyl chlorides or benzoyl chlorides. These reactions proceed smoothly in the presence of zinc powder to afford the products in moderate to excellent yields.
- Wu, Xiao-Feng,Schranck, Johannes,Neumann, Helfried,Beller, Matthias
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supporting information; experimental part
p. 40 - 44
(2012/03/11)
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- Palladium-catalyzed carbonylative suzuki coupling of benzyl halides with potassium aryltrifluoroborates in aqueous media
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A general palladium-catalyzed carbonylative cross-coupling reaction of benzyl chlorides with potassium aryltrifluoroborates in water has been developed. Applying this improved methodology 16 different 1,2-diarylethanones have been synthesized in 40-89% yield. Copyright
- Wu, Xiao-Feng,Neumann, Helfried,Beller, Matthias
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experimental part
p. 788 - 792
(2011/05/15)
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- Arylation of α-pivaloxyl ketones with arylboronic reagents via Ni-catalyzed sp3 C-O activation
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A Suzuki-Miyaura coupling of α-pivaloxyl ketones via Ni-catalyzed sp3 C-O activation to produce α-aryl ketones is developed. This study offers a convenient method to construct α-arylation products from readily available α-hydroxyl carbonyl compounds.
- Huang, Kun,Li, Gang,Huang, Wei-Ping,Yu, Da-Gang,Shi, Zhang-Jie
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p. 7224 - 7226
(2011/08/09)
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- Direct synthesis of aryl ketones by palladium-catalyzed desulfinative addition of sodium sulfinates to nitriles
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Mild yet direct: A convenient and efficient method for the synthesis of various aryl ketones by palladium-catalyzed desulfinative addition of aromatic sulfinic acid sodium salts to various nitriles is described (see scheme). Aromatic and aliphatic nitriles are successfully reacted with arenesulfinic acid sodium salts to form aryl ketones in good yields.
- Liu, Jing,Zhou, Xianya,Rao, Honghua,Xiao, Fuhong,Li, Chao-Jun,Deng, Guo-Jun
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supporting information; experimental part
p. 7996 - 7999
(2011/08/22)
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