- Novelmeta-benzothiazole and benzimidazole functionalised POCOP-Ni(ii) pincer complexes as efficient catalysts in the production of diarylketones
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The synthesis of four novel non-symmetric Ni(ii)-POCOP pincer complexesmeta-functionalized with either benzothiazole or benzimidazole at the central aryl ring is described. All complexes were fully characterised in solution by various analytical techniques and the molecular structures in the solid state of complexes1b,2aand2bwere unequivocally determined by single crystal X-ray diffraction analysis. In addition, the Ni(ii)-POCOP pincer complexes were efficiently used as catalysts in the synthesis of diarylketones by cross-coupling reactions of functionalized benzaldehydes and boronic acid derivatives under relatively mild conditions. An important aspect of this transformation is the dependence on the steric properties of the donor groups (OPR2) of the pincer ligands, the more active compounds having the phosphinitos bearing isopropyl groups (1aand2a) than those containingtert-butyl substituents (1band2b).
- Castillo-García, Antonio A.,González-Sebastián, Lucero,Lomas-Romero, Leticia,Hernandez-Ortega, Simon,Toscano, Ruben A.,Morales-Morales, David
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p. 10204 - 10216
(2021/06/18)
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- Synthesis of Acyl Fluorides via DAST-Mediated Fluorinative C-C Bond Cleavage of Activated Ketones
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A new protocol for preparation of acyl fluorides was developed by recognizing activated ketones as starting materials. The method provides a different scope compared with previously reported methods that employ carboxylic acids as substrates. A working hypothesis of pull-and-push-driven fluorinative C-C bond cleavage was successfully demonstrated by the simple addition of diethylaminosulfur trifluoride (DAST) derivatives to α-oximinoketones. The designed reaction system led to a highly efficient and chemoselective reaction. The wide availability of the ketones allowed for a range of synthetically useful aryloyl and aliphatic acyl fluorides including those containing chiral skeletons. The method is mild, fast, scalable, and potentially one-pot operative.
- Kim, Danhee,Lim, Hee Nam
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p. 7465 - 7469
(2020/10/09)
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- Kinetically Controlled, Highly Chemoselective Acylation of Functionalized Grignard Reagents with Amides by N?C Cleavage
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The direct transition-metal-free acylation of amides with functionalized Grignard reagents by highly chemoselective N?C cleavage under kinetic control has been accomplished. The method offers rapid and convergent access to functionalized biaryl ketones through transient tetrahedral intermediates. The direct access to functionalized Grignard reagents by in situ halogen–magnesium exchange promoted by the versatile turbo-Grignard reagent (iPrMgCl?LiCl) permits excellent substrate scope with respect to both the amide and Grignard coupling partners. These reactions enable facile, operationally simple and chemoselective access to tetrahedral intermediates from amides under significantly milder conditions than chelation-controlled intermediates. This novel direct two-component coupling sets the stage for using amides as acylating reagents in an alternative paradigm to the metal-chelated approach, acyl metals and Weinreb amides.
- Li, Guangchen,Szostak, Michal
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supporting information
p. 611 - 615
(2020/01/02)
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- Synthesis of biaryl ketones by arylation of Weinreb amides with functionalized Grignard reagents under thermodynamic controlvs.kinetic control ofN,N-Boc2-amides
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A highly efficient method for chemoselective synthesis of biaryl ketones by arylation of Weinreb amides (N-methoxy-N-methylamides) with functionalized Grignard reagents is reported. This protocol offers rapid entry to functionalized biaryl ketones after Mg/halide exchange with i-PrMgCl·LiCl under operationally-simple and practical reaction conditions. The scope of the method is highlighted in >40 examples, including bioactive compounds and pharmaceutical derivatives. Collectively, this transition-metal-free approach offers a major advantage over the recently established cross-coupling of amides by oxidative addition of N-C(O) bonds. Considering the utility of amide acylation reactions in modern synthesis, we expect that this method will be of broad interest.
- Li, Guangchen,Szostak, Michal
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supporting information
p. 3827 - 3831
(2020/06/03)
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- Hydrogen bond donor solvents enabled metal and halogen-free Friedel–Crafts acylations with virtually no waste stream
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We have developed a metal and halogen-free Friedel–Crafts acylation protocol with virtually no waste stream generation. We propose a hydrogen bonding donor solvent will form a hydrogen bonding network and may provide significant rate enhancement for Friedel–Crafts reactions. Trifluoroacetic acid is one of the strongest H-bond donor solvents, which is also volatile and can be easily recovered by distillation without need for reaction workup. Our protocol is a ‘green’ Friedel–Crafts acylation process: 1) the catalyst can be recovered and reused; 2) using halogen free starting material (carboxylic acids anhydride or carboxylic acids); 3) no need for aqueous reaction work-up; 4) minimum or no waste steam generation.
- Liu, Guangchang,Xu, Bo
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supporting information
p. 869 - 872
(2018/02/09)
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- Synthesis and palladium(II) metal chemistry of thiazoline/imidazoline derived ligands: An efficient catalyst for cross-coupling reactions of arylboronic acids with acid chlorides and aryl halides
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The synthesis, reactivity, spectroscopic characterization and catalytic activities of a series of Pd(II) complexes bearing the chelating ligands 2-(4,5-dihydrothiazol-2-yl)aniline (2) and 2-(4,5-dihydro-1H-imidazol-2-yl)aniline (3) are reported. The reactions of 2 with [Pd(COD)Cl2] in 1:1 and 1:2 (ligand into metal and metal into ligand) molar ratios afforded the mononuclear complexes, PdCl2{κ2?N,S ? 2?(4,5-dihydrothiazol-2-yl)aniline} (4), Pd{κ2?N,N’?2?(4,5-dihydrothiazol-2-yl)aniline}2 (5) and Pd{κ12?N,N’?κ22?N,S ? 2?(4,5-dihydrothiazol-2-yl)aniline}2 (6), respectively, in good yields. The neutral mononuclear palladium complexes PdCl2{κ2?N,N’?(4,5-dihydro-1H-imidazol-2-yl)aniline} (7) and Pd{κ2?N,N’?2?(4,5-dihydro-1H-imidazol-2-yl)aniline}2 (8) were synthesized using [Pd(COD)Cl2] with appropriate molar ratios. The palladium complexes 4–8 were evaluated for their catalytic activities in base assisted cross coupling reactions between acid chlorides and aryl halide with boronic acids. The complex 4 was found to be an efficient catalyst for producing unsymmetrical ketones (TOF = 19.8 min?1) while complex 7 was effective for making biaryls (TOF = 19.8 min?1).
- Sudharsan, Murugesan,Suresh
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p. 598 - 608
(2018/09/18)
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- Pd-NHC catalysed Carbonylative Suzuki coupling reaction and its application towards the synthesis of biologically active 3-aroylquinolin-4 (1H)-one and acridone scaffolds
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We have unfolded a convenient and mild protocol for the synthesis of diaryl ketones via Pd- NHC catalysed carbonylative Suzuki coupling reaction. Notably, this method offers advantages like no use of toxic CO gas, shorter reaction time, high yield, and broad substrate scope. Several sensitive functional groups (like-COMe, -COOMe, -F, -Cl, -Br, -NH2, -CN) are well tolerated in this reaction. In addition, we have also demonstrated a new efficient route for the synthesis of biologically active and pharmaceutically important 2-substituted 3-Aroylquinolin-4(1H)-ones and acridone scaffolds.
- Ghosh, Prasanjit,Ganguly, Bhaskar,Das, Sajal
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- Carbonylative Suzuki Coupling Reaction Catalyzed by a Hydrospirophosphorane Palladium Complex
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A Pd complex with the H-spirophosphorane ligand, PdCl2{P(OCMe2CMe2O)OC6H4NH2} (Cat. 1), was used as the catalyst in the carbonylative Suzuki coupling of substituted iodobenzenes with arylboronic acids and with sodium tetraphenylborate. Substituted diarylketones were obtained in good to excellent yields and a selectivity over 95 % under 1 atm of CO with 1.5 mol % of the catalyst. The promoting role of the H-spirophosphorane ligand in the catalytic process was evidenced. We used X-ray photoelectron spectroscopy, TEM, and 31P NMR spectroscopy to reveal that during the reaction Cat. 1 undergoes transformation into Pd complexes that bear the spirophosphorane ligand or other P ligands formed by its dealkylation and to Pd nanoparticles. All these Pd species contribute to the high productivity of the system.
- Wójcik, Przemys?aw,Sygellou, Labrini,Gniewek, Andrzej,Skar?yńska, Anna,Trzeciak, Anna
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p. 4397 - 4409
(2017/11/21)
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- Efficient Synthesis of Diaryl Ketones by Nickel-Catalyzed Negishi Cross-Coupling of Amides by Carbon–Nitrogen Bond Cleavage at Room Temperature Accelerated by a Solvent Effect
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The first Negishi cross-coupling of amides for the synthesis of versatile diaryl ketones by selective C?N bond activation under exceedingly mild conditions is reported. The cross-coupling was accomplished with bench-stable, inexpensive precatalyst [Ni(PPh3)2Cl2] that shows high functional-group tolerance and enables the synthesis of highly functionalized diaryl ketone motifs. The coupling occurred with excellent chemoselectivity favoring the ketone (cf. biaryl) products. Notably, this process represents the mildest conditions for amide N?C bond activation accomplished to date (room temperature, 10 min). Considering the versatile role of polyfunctional biaryl ketone linchpins in modern organic synthesis, availability, and excellent functional-group tolerance of organozinc reagents, this strategy provides a new platform for amide N?C bond/organozinc cross-coupling under mild conditions.
- Shi, Shicheng,Szostak, Michal
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p. 10420 - 10424
(2016/07/21)
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- One-Pot Synthesis of Arylketones from Aromatic Acids via Palladium-Catalyzed Suzuki Coupling
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A palladium-catalyzed one-pot procedure for the synthesis of aryl ketones has been developed. Triazine esters when coupled with aryl boronic acids provided aryl ketones in moderate to excellent yields (up to 95%) in the presence of 1 mol % Pd(PPh3)2Cl2 for 30 min. (Chemical Equation Presented).
- Wu, Hongxiang,Xu, Baiping,Li, Yue,Hong, Fengying,Zhu, Dezhao,Jian, Junsheng,Pu, Xiaoer,Zeng, Zhuo
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p. 2987 - 2992
(2016/04/26)
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- Synthesis of ketones via organolithium addition to acid chlorides using continuous flow chemistry
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An efficient method for the synthesis of ketones using organolithium and acid chlorides under continuous flow conditions has been developed. In contrast to standard batch chemistry, over-addition of the organolithium to the ketone for the formation of the undesired tertiary alcohol has been minimised representing a direct approach toward ketones.
- Moon, Soo-Yeon,Jung, Seo-Hee,Bin Kim,Kim, Won-Suk
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p. 79385 - 79390
(2015/10/06)
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- One-pot Unsymmetrical Ketone Synthesis Employing a Pyrrole-Bearing Formal Carbonyl Dication Linchpin Reagent
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A one-pot procedure for the synthesis of unsymmetrical ketones utilizing a pyrrole-bearing carbonyl linchpin reagent (carbonyl linchpin N,O-dimethylhydroxylamine pyrrole; CLAmP) is reported. In contrast to other carbonyl dielectrophile equivalents, CLAmP enables the synthesis of ketones from a variety of organolithium and Grignard reagents. The electrophilic nature of CLAmP enables the addition of less reactive as well as thermally unstable nucleophiles. CLAmP was designed to form kinetically stable tetrahedral intermediates upon the addition of organometallic nucleophiles. Evidence for the existence of persistent tetrahedral intermediates was obtained through in situ IR studies.
- Heller, Stephen T.,Newton, James N.,Fu, Tingting,Sarpong, Richmond
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supporting information
p. 9839 - 9843
(2015/08/19)
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- An efficient and recyclable thermoregulated phosphine-palladium catalyst for the carbonylative Suzuki coupling of aryl halides with arylboronic acids in water
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An efficient protocol has been developed for the carbonylative Suzuki coupling of aryl halides using the thermoregulated phosphine-palladium as a reusable catalyst in pure water. This protocol was applied to a wide variety of hindered and functionalized aryl iodides and bromides with arylboronic acids, to afford the desired biaryl ketones in good to high yields. The palladium catalyst was easily recovered in the aqueous phase and reused up to eight cycles without a significant decrease in its activity.
- Hao, Yuanping,Jiang, Jingyang,Wang, Yanhua,Jin, Zilin
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p. 106 - 110
(2015/09/28)
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- Palladacycle-Catalyzed Carbonylative Suzuki-Miyaura Coupling with High Turnover Number and Turnover Frequency
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This work reports the carbonylative Suzuki-Miyaura coupling of aryl iodides catalyzed by palladacycles. More importantly, the palladacycles have been used to generate high turnover numbers (TON's) and turnover frequencies (TOF's). A range of aryl iodides can be coupled with arylboronic acids, generating TON's in the range of 106 to 107 and TOF's in the range of 105 to 106 h-1. Comparison of the palladacycles with a conventional palladium source shows their superiority in generating high TON's and TOF's.
- Gautam, Prashant,Bhanage, Bhalchandra M.
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p. 7810 - 7815
(2015/08/18)
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- Preparation of acylthiophenes by iron(III) chloride catalyzed reactions of tris(2-thienyl)stibanes with acyl chlorides
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The reactions of tris(2-thienyl)stibanes with various acyl chlorides, using a catalytic amount of iron(III) chloride, afforded 2-acylthiophenes. Iron(III) chloride is presumed to act as a Lewis acid, and the ipso substituent of each 2-thienyl group of tris(2-thienyl)stibane is replaced with an acyl group. The reaction is highly atom-efficient in that all three thiophene rings of tris(2-thienyl)stibane take part in the reaction. The reaction procedure is so simple that it can also be carried out under solvent-free and aerobic conditions.
- Kakusawa, Naoki,Nakagawa, Yoshie,Toshima, Yutarou,Yasuike, Shuji,Kurita, Jyoji
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p. 1170 - 1175
(2015/07/15)
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- Expedient carbonylation of aryl halides in aqueous or neat condition
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An expedient and versatile, microwave-assisted procedure for the carbonylation of aryl halides with boronic acids, alcohols or amines in water or under neat conditions has been developed. The reaction is catalyzed by fluorous, oxime-based palladacycle 1 that shows an excellent recyclable property and low levels of Pd leaching. To demonstrate the usefulness of the protocol, we applied it to the preparation of compounds of pharmaceutical interest, including a precursor of the reverse transcriptase inhibitor, niacin, benzocaine and butamben.
- Ang, Wei Jie,Lo, Lee-Chiang,Lam, Yulin
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p. 8545 - 8558
(2014/12/11)
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- TFAA/H3PO4-Mediated C-2 acylation of thiophene: A direct synthesis of known and novel thiophene derivatives of pharmacological interest
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A number of aliphatic and aromatic carboxylic acids were reacted with thiophene in the presence of trifluoroacetic anhydride and H3PO 4 to give a variety of acylated thiophenes in good to excellent yields. The methodology was used to prepare known nonsteroidal anti-inflammatory drug-based novel compounds of potential pharmacological significances. Molecular modeling studies were carried out by using nonsteroidal anti-inflammatory drug-based thiophene derivatives to assess their cyclooxygenase inhibiting potential in silico. On the basis of docking studies followed by subsequent in vitro assay, indomethacin-based thiophene derivative was identified as a novel cyclooxygenase-2 inhibitor with balanced selectivity.
- Bindu,Naini, Shravan Reddy,Shanmukha Rao,Dubey,Pal, Sarbani
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p. 586 - 593
(2014/06/10)
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- Efficient, recyclable and phosphine-free carbonylative Suzuki coupling reaction using immobilized palladium ion-containing ionic liquid: Synthesis of aryl ketones and heteroaryl ketones
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The carbonylative Suzuki coupling reaction of aryl and heteroaryl iodides was studied by using immobilized palladium ion-containing ionic liquid (ImmPd-IL). The protocol was optimized with respect to various reaction parameters, applied to a wide variety of substituted aryl/heteroaryl iodides and various aryl/heteroaryl boronic acids with different steric and electronic properties, and afforded the corresponding products in good to excellent yield. This is an efficient, heterogeneous catalyst which avoids the use of phosphine ligands, and its reusability was tested in up to four consecutive cycles. The recycled catalyst was characterized by using XPS analysis.
- Khedkar, Mayur V.,Sasaki, Takehiko,Bhanage, Bhalchandra M.
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p. 7791 - 7797
(2013/06/27)
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- Catalytic Friedel-Crafts acylation: Magnetic nanopowder CuFe 2O4 as an efficient and magnetically separable catalyst
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Catalytic regioselective Friedel-Crafts acylation of an array of anisoles/arenes with various acid chlorides using 5-20 mol % of magnetic nanopowder CuFe2O4 is reported. Unlike the conventional Friedel-Crafts reactions, which are catalyzed by moisture sensitive homogeneous catalysts/promoters, the nanopowder CuFe2O4 catalyst is moisture insensitive and the product/ketone-catalyst isolation is easily achieved using the magnetic properties of CuFe2O4.
- Parella, Ramarao,Naveen,Kumar, Amit,Babu, Srinivasarao Arulananda
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p. 1738 - 1742
(2013/03/28)
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- Synthesis of arylketones by ruthenium-catalyzed cross-coupling of aldehydes with arylboronic acids
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The first ruthenium-catalyzed cross-coupling of aldehydes with arylboronic acids is reported. Various aliphatic and aromatic aldehydes are transformed to the corresponding arylketones. A total of 31 examples with moderate to excellent yields are presented, together with the results of an initial mechanistic investigation.
- Li, Hong,Xu, Yuan,Shi, Erbo,Wei, Wei,Suo, Xiangqiang,Wan, Xiaobing
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supporting information; experimental part
p. 7880 - 7882
(2011/08/06)
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- Easy-to-execute carbonylative arylation of aryl halides using molybdenum hexacarbonyl: Efficient synthesis of unsymmetrical diaryl ketones
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A versatile procedure for the synthesis of unsymmetrical diaryl ketones through a palladium-catalyzed carbonylative arylation of iodoarenes through easy-to-handle molybdenum hexacarbonyl as a condensed source of carbon monoxide is described. This method provides an efficient route to a wide variety of substituted diaryl ketones without direct use of high-pressure carbon monoxide. Copyright
- Jafarpour, Farnaz,Rashidi-Ranjbar, Parviz.,Kashani, Asieh Otaredi
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experimental part
p. 2128 - 2132
(2011/05/09)
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- Ligand-free Pd-catalyzed carbonylative cross-coupling reactions under atmospheric pressure of carbon monoxide: Synthesis of aryl ketones and heteroaromatic ketones
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The carbonylative Suzuki cross-coupling reactions of boronic acids with aryl iodides catalyzed by Pd2(dba)3 as a ligand-free catalyst under atmospheric pressure of carbon monoxide has been firstly developed. Under mild reaction conditions, a broad range of aryl/heteroaryl iodides and aryl/heteroaryl boronic acids were selectively coupled to afford the corresponding diaryl ketones in good to excellent yields at low catalyst loadings (0.05 to 2 mol-%). Moreover, the catalyst can also be recycled. The carbonylative Suzuki cross-coupling reactions of boronic acids with aryl iodides catalyzed by Pd2(dba)3 as a ligand-free catalyst under an atmosphere of carbon monoxide has been developed. A broad range of aryl/heteroaryl iodides and aryl/heteroaryl boronic acids were selectively coupled to afford the corresponding diaryl ketones in good to excellent yields. The catalyst can also be recycled.
- Li, Hongling,Yang, Min,Qi, Yanxing,Xue, Jijun
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supporting information; experimental part
p. 2662 - 2667
(2011/06/25)
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- Mobilizing Cu(I) for carbon-carbon bond forming catalysis in the presence of thiolate. Chemical mimicking of metallothioneins
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Copper(I) is rendered catalytically viable in the presence of thiolate by the design of a small molecule chemical analogue of the metallothionein system in which an N-O reactant serves the same conceptual purpose of the S-S reactant of the biological system.
- Zhang, Zhihui,Lindale, Matthew G.,Liebeskind, Lanny S.
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supporting information; experimental part
p. 6403 - 6410
(2011/06/19)
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- Pd/C: An efficient, heterogeneous and reusable catalyst for phosphane-free carbonylative suzuki coupling reactions of aryl and heteroaryl iodides
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The carbonylative Suzuki coupling reaction of aryl boronic acid with different aryl and heteroaryl iodides was carried out to synthesize various unsymmetrical biaryl ketones by using Pd/C as an efficient, heterogeneous and reusable catalyst. The catalyst exhibits remarkable activity, and its reusability was tested up to four consecutive cycles. The reaction is applicable for various aryl and heteroaryl iodides having different steric and electronic properties. It provides good to excellent yield of the desired products. The developed protocol is advantageous with regard to the ease in handling the catalyst and the simple work-up procedure; it is also an environmentally benign process with effective catalyst recyclability. A facile protocol has been developed for the carbonylative Suzuki coupling reaction of aryl and heteroaryl iodides with Pd/C as effective, heterogeneous, reusable catalyst. The system is applicable for a wide variety of aryl and heteroaryl iodides. Copyright
- Khedkar, Mayur V.,Tambade, Pawan J.,Qureshi, Ziyauddin S.,Bhanage, Bhalchandra M.
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experimental part
p. 6981 - 6986
(2011/03/17)
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- Catalytic Friedel-Crafts acylation and benzoylation of aromatic compounds using activated hematite as a novel heterogeneous catalyst
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Catalytic Friedel-Crafts acylation of benzene and unactivated benzenes such as chlorobenzene and nitrobenzene have been successfully carried out using activated hematite (α-Fe2O3) as a new, heterogeneous and green catalyst. Sonication of neat α-Fe2O3 in a water bath under air atmosphere at room temperature followed by heating at 200°C, dramatically increase the activity of α-Fe2O 3. With the catalyst loading as low as 5.0mol%, a wide variety of benzene derivatives were easily converted into the corresponding acylated products in a clean and high-yielding acylation reaction. It was found that the activated α-Fe2O3 could be efficiently recycled and reused several times by simple washing with ethyl acetate, this cannot be attained with most of the traditional catalysts. Copyright
- Sharghi, Hashem,Jokar, Mahboubeh,Doroodmand, Mohammad Mahdi,Khalifeh, Reza
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experimental part
p. 3031 - 3044
(2011/02/21)
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- Pd(0)/C-catalyzed cross-couplings of acyl chlorides with triarylbismuths as atom-efficient sub-stoichiometric multi-coupling reagents
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Aromatic and hetero-aromatic acyl chlorides were efficiently cross-coupled with triarylbismuths as atom-efficient nucleophilic organometallic coupling reagents in sub-stoichiometric amounts using catalytic Pd(0)/C. Thus, the coupling reactions of various triarylbismuths with a variety of acyl chlorides furnished a plethora of both symmetrical/unsymmetrical aromatic and hetero-aromatic ketones in high yields.
- Rao, Maddali L.N.,Jadhav, Deepak N.,Venkatesh, Varadhachari
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experimental part
p. 4268 - 4271
(2009/10/26)
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- Phosphane-free palladium-catalyzed carbonylative suzuki coupling reaction of aryl and heteroaryl iodides
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The carbonylative cross-coupling reaction of an arylboronic acid with an aryl iodide and a heteroaryl iodide to give unsymmetrical biaryl ketones was carried out by using Pd(tmhd)2/Pd (OAc)2 as a phosphane-free catalyst. Various aryl and heteroaryl iodides with different arylboronic acid derivatives provided, good, to excellent yields of the desired products under optimized reaction conditions. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009.
- Tambade, Pawan J.,Patil, Yogesh P.,Panda, Anil G.,Bhanage, Bhalchandra M.
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experimental part
p. 3022 - 3025
(2009/11/30)
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- MoO2Cl2 as a novel catalyst for Friedel-Crafts acylation and sulfonylation
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The use of MoO2Cl2 as a novel catalyst for Friedel-Crafts acylation and sulfonylation is described. A series of aromatic ketones and sulfones were prepared in moderate to good yields using acyl chloride or sulfonyl chloride in the presence of MoO2Cl2 (20 mol %), under solvent-free conditions.
- de Noronha, Rita G.,Fernandes, Ana C.,Rom?o, Carlos C.
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experimental part
p. 1407 - 1410
(2009/06/18)
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- Atom-efficient cross-coupling reactions of triarylbismuths with acyl chlorides under Pd(0) catalysis
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The atom-efficient cross-coupling reaction of triarylbismuths with a variety of aliphatic, aromatic, and hetero-aromatic acyl chlorides was demonstrated to afford high yields of cross-coupled ketones under palladium catalysis. The corresponding cross-coupling reaction with diacid chlorides also furnished bis-coupled ketones in good yields.
- Rao, Maddali L.N.,Venkatesh, Varadhachari,Banerjee, Debasis
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p. 12917 - 12926
(2008/03/28)
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- One-step preparation of α-chlorostyrenes
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α-Chlorostyrenes were prepared via a one-step method involving Friedel-Crafts reaction of various aromatic substrates with acid chlorides in the presence of a heterogeneous Si-Fe catalyst.
- Borate, Hanumant B.,Gaikwad, Abaji G.,Maujan, Suleman R.,Sawargave, Sangmeshwer P.,Kalal, Kamalakar M.
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p. 4869 - 4872
(2008/02/05)
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- Oligothiophene-linked bisnaphthopyrans: Sequential and temperature- dependent photochromism
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Photochromic bisnaphthopyrans linked with oligothiophenes were synthesized and their photochromic behavior studied. Sequential and temperature-dependent photochromism was observed in the oligothiophene linked bisnaphthopyrans. The kinetics of photo and thermal processes in bisnaphthopyrans in comparison with naphthopyrans were studied, Substituent and linking effects on the photochromic properties are discussed. We demonstrate that the cross-talk between the two photochromophores is dependent on the length of the oligothiophene linker. The presence of the bithiophene linker led to high colorability and high quantum yield of coloration.
- Zhao, Weili,Carreira, Erick M.
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p. 2671 - 2688
(2008/03/14)
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- C-acylation of 2-methylfuran and thiophene using N-acylbenzotriazoles
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Reactions of 2-methylfuran and thiophene with readily available N-acylbenzotriazoles (RCOBt, where R = 4-tolyl, 4-methoxyphenyl, benzyl, 4-nitrophenyl, 4-diethylaminophenyl, 2-pyridyl and 1-naphthyl) in the presence of TiCl4 or ZnBr2 produced 2-methyl-4-acylfurans 2a-e and 2-acylthiophenes 3a-f in average yields of 54 % and 75 %, respectively. Literature yields for the preparation of the same compounds are significantly lower.
- Katritzky, Alan R.,Suzuki, Kazuyuki,Singh, Sandeep K.
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p. 175 - 178
(2007/10/03)
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- o-Iodoxybenzoic Acid (IBX) as a Viable Reagent in the Manipulation of Nitrogen- and Sulfur-Containing Substrates: Scope, Generality, and Mechanism of IBX-Mediated Amine Oxidations and Dithiane Deprotections
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o-Iodoxybenzoic acid (IBX), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the dehydrogenation of amines in addition to facilitating the oxidative cleavage of dithioacetals and dithioketals. Through the development of relevant IBX-based protocols, a plethora of useful synthetic intermediates, including imines, oximes, ketones, and aromatic N-heterocycles, were found to be readily accessible under notably mild conditions. Further investigation of these transformations led to the elucidation of valuable mechanistic details, resulting in the conclusion that they proceed via ionic rather than single electron transfer (SET) pathways.
- Nicolaou,Mathison, Casey J. N.,Montagnon, Tamsyn
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p. 5192 - 5201
(2007/10/03)
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- Infrared and Nuclear Magnetic Resonance Properties of Benzoyl Derivatives of Five-membered Monoheterocycles and Determination of Aromaticity Indices
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Benzophenones, 2-benzoylthiophenes, 2-benzoylpyrroles, and 2-benzoylfurans, which have substituents at m- and p-positions of the benzoyl ring were prepared and their ir and nmr spectra were obtained in 0.1 M chloroform-d solution. The chemical shift values of each series were plotted against the Hammett substituent parameters to give good correlation, with the exception of the ortho-Hs and -Cs. The slopes as well as the differences in chemical shift gave sets of meaningful values for the indices of aromaticy.
- Jeon, Kyu Ok,Jun, Jung Ho,Yu, Ji Sook,Lee, Chang Kiu
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p. 763 - 771
(2007/10/03)
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- Synthesis and structure-activity relationship for new series of 4-phenoxyquinoline derivatives as specific inhibitors of platelet-derived growth factor receptor tyrosine kinase
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We discovered a new series of 4-phenoxyquinoline derivatives as potent and selective inhibitors of the platelet-derived growth factor receptor (PDGFr) tyrosine kinase. We researched the highly potent and selective inhibitors on the basis of both PDGFr and epidermal growth factor receptor (EGFr) inhibitory activity. First, we found a compound, Ki6783 (1), which inhibited PDGFr autophosphorylation at 0.13 μM, but it did not inhibit EGFr autophosphorylation at 100 μM. After extensive explorations, we found the two desired compounds, Ki6896 (2) and Ki6945 (3), which are substituted by benzoyl and benzamide at the 4-position of the phenoxy group on 4-phenoxyquinoline, respectively. These inhibitory activities were 0.31 and 0.050 μM, respectively, but neither of them inhibited EGFr autophosphorylation at 100 μM. We further investigated the profile of both compounds toward various tyrosine and serine/threonine kinases. The three compounds specifically inhibited PDGFr rather than the other kinases.
- Kubo, Kazuo,Ohyama, Shin-Ichi,Shimizu, Toshiyuki,Takami, Atsuya,Murooka, Hideko,Nishitoba, Tsuyoshi,Kato, Shinichiro,Yagi, Mikio,Kobayashi, Yoshiko,Iinuma, Noriko,Isoe, Toshiyuki,Nakamura, Kazuhide,Iijima, Hiroshi,Osawa, Tatsushi,Izawa, Toshio
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p. 5117 - 5133
(2007/10/03)
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- Synthesis of arylcarbinols and/or arylketones end capped thiophene and 2,2′-bithiophene
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Synthesis of arylmethanol of thiophene and 2,2′-bithiophene derivatives (4, 5, 8, 9 and 13) and the corresponding ketones (6, 10, 11 and 14) which were prepared by lithiation/addition exchange sequence on the arylbromides (2, 3 and 12) followed by trappin
- Hamad, Abdel-Sattar S.
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- Quinoline and quinazoline derivatives inhibiting platelet-derived growth factor receptor autophosphorylation and pharmaceutical compositions containing the same
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The present invention relates to novel quinoline derivatives and quinazoline derivatives represented by the following formula (I): STR1 [wherein R 1 and R 2 are each independently H or C 1 -C 4 -alkyl, or R 1 and R 2 together form C 1 -C 3 -alkylene, X is O, S or CH 2, W is CH or N, and Q is a substituted aryl group or substituted heteroaryl group] and their pharmaceutically acceptable salts, having platelet-derived growth factor receptor autophosphorylation inhibitory activity, to pharmaceutical compositions containing these compounds, and to methods for the treatment of diseases associated with abnormal cell growth such as tumors.
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- Palladium- and copper-catalyzed cross-coupling and carbonylative cross-coupling of organotellurium compounds with organostannanes
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The palladium- and copper-catalyzed cross-coupling of diaryl- or divinyl tellurium dichlorides with organostannanes has been achieved in the presence of PdCl2 (10 mol%) or CuI (10 mol%) with Cs2CO3 (2 equiv.) in MeCN in good to moderate yields; alternatively, the palladium- and copper-catalyzed carbonylative cross-coupling of organotellurium dichlorides with organostannanes was readily accomplished under atmospheric pressure of CO in good to moderate yields.
- Kang, Suk-Ku,Lee, Sang-Woo,Ryu, Hyung-Chul
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p. 2117 - 2118
(2007/10/03)
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- One-pot synthesis of ketones using N-methoxy-N-methyl-2-pyridyl urethane
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The one-pot reaction of N-methoxy-N-methyl-2-pyridyl urethane with Grignard and organolithium reagents provided an efficient method for the preparation of unsymmetrical ketones.
- Lee, Na Ra,Lee, Jae In
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p. 1249 - 1255
(2007/10/03)
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- Ni(acac)2-catalyzed cross-coupling and carbonylative cross-coupling of organostannanes with hypervalent iodonium salts
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The Ni-catalyzed cross-coupling and carbonylative cross-coupling of organostannanes with hypervalent iodonium salts were achieved in the presence of Ni(acac)2 (10 mol%) in NMP at 70°C in moderate yields. The Royal Society of Chemistry 1999.
- Kang, Suk-Ku,Ryu, Hyung-Chul,Lee, Sang-Woo
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p. 2661 - 2663
(2007/10/03)
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- Palladium-catalyzed carbonylative cross-coupling of organoboranes with hypervalent iodonium salts: Synthesis of aromatic ketones
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The cross-coupling reaction of organoboronic acids and carbon monoxide (1 atm) with aryl-, alkenyl-, and alkynyliodonium salts at room temperature afforded unsymmetric aromatic ketones in moderate yields.
- Kang, Suk-Ku,Lim, Kwon-Ho,Ho, Pil-Su,Yoon, Seok-Keun,Son, Hoe-Joo
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p. 1481 - 1489
(2007/10/03)
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- Palladium-Catalyzed Carbonylative Cross-Coupling Reaction of Arylboronic Acids with Aryl Electrophiles: Synthesis of Biaryl Ketones
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The carbonylative cross-coupling reaction of arylboronic acids with aryl electrophiles (ArI, ArBr, and ArOTf) to yield unsymmetrical biaryl ketones was carried out in anisole at 80°C in the presence of a palladium catalyst and a base. The reaction selectively proceeded under an atmospheric pressure of carbon monoxide when PdCl2(PPh3)2 (3 mol %)/K2CO3 (3 equiv) were used for aryl iodides and PdCl2(dppf) (3 mol %)/K2CO3 (3 equiv)/KI (3 equiv) for the bromides or the triflates. The carbonylation of arylboronic acids with benzyl halides gave aryl benzyl ketones.
- Ishiyama, Tatsuo,Kizaki, Hiroe,Hayashi, Takahiro,Suzuki, Akira,Miyaura, Norio
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p. 4726 - 4731
(2007/10/03)
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- Palladium-catalyzed carbonylative coupling of iodonium salts with organostannanes under aqueous conditions: Synthesis of unsymmetrical vinyl and aromatic ketones
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The palladium-catalyzed carbonylative coupling reaction of hypervalent iodonium salts with organostannanes was accomplished in the presence of PdCl2 (0.2 mol%) under atmospheric pressure of carbon monoxide at room temperature under aqueous conditions.
- Kang, Suk-Ku,Ho, Pil-Su,Yoon, Seok-Keun,Lee, Ju-Cheol,Lee, Kyung-Ju
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p. 823 - 825
(2007/10/03)
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- 2-(Trifluoromethylsulfonyloxy)pyridine as a Reagent for the Ketone Synthesis from Carboxylic Acids and Aromatic Hydrocarbons
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A new reagent 2-(trifluoromethylsulfonyloxy)pyridine (TFOP) was prepared by the reaction of sodium salt of 2-pyridinol with trifluoromethylsulfonyl chloride in dioxane.The conpound TFOP in trifluoroacetic acid has been found to intermolecularly dehydrate from benzoic acid and aromatic hydrocarbons to give the corresponding benzophenones in high yield.It was further elucidated, in the reaction of fluorene, that a variety of carboxylic acids can be used as the acyl precursor for the aromatic ketone synthesis in conjunction with the TFOP/TFA system.This acylation procedure has been applied to the synthesis of 2-acylthiophenes, which are hard to prepare in a satisfactory yield by the classical Friedel-Crafts reaction using aluminum chloride as the catalyst.
- Keumi, Takashi,Yoshimura, Kiichiro,Shimada, Masakazu,Kitajima, Hidehiko
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p. 455 - 460
(2007/10/02)
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