- SYNTHESIS OF ARYLBORONIC ACIDS VIA THE REACTION OF BORANE WITH ARYLMAGNESIUM HALIDES
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The reaction of borane complexes with arylmagnesium halides produces the corresponding arylborohydrides in high yield.The arylborohydrides are readily hydrolyzed to the arylboronic acids.The syntheses are conveniently carried out in one pot.The reaction mechanism was clarified via a boron-11 NMR study.
- Kabalka, George W.,Sastry, Usha,Sastry, K.A.R.,Knapp, Furn F.,Srivastava, Prem C.
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- Preparation method of monohalogenated phenylboronic acid
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The invention relates to the technical field of chemical synthesis, and particularly discloses a preparation method of monohalogenated phenylboronic acid. The preparation method comprises the following steps of: by taking dihalogenated benzene as a raw material and a mixture of lithium salt and alkaline ionic liquid as a catalyst, carrying out Grignard exchange with R1MgCl to generate monohalogenated phenyl magnesium chloride, reacting with B (OR) 3 to generate monohalogenated phenyl borate, and hydrolyzing under acidic conditions to obtain monohalogenated phenylboronic acid. The HPLC (High Performance Liquid Chromatography) content of the monohalogenated phenylboronic acid prepared by the method is greater than 99.5%; the total yield of the product is greater than 80%, the contents of monohalogenated phenylboronic acid and phenyldiboronic acid impurities of another halogen are both less than 0.003%, the requirements of modern fine chemical synthesis are completely met, the raw materials are easily available, the operation is simple, the safety is high, and the industrial production of monohalogenated phenylboronic acid is realized.
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Paragraph 0080-0083
(2020/09/20)
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- Synthesis method of P-chlorophenylboronic acid
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The invention belongs to the technical field of organic synthesis, and particularly relates to a synthesis method of p-chlorophenylboronic acid, which comprises the following steps: carrying out Friedel-Crafts reaction between chlorobenzene used as a raw material and boron trichloride under the action of a catalyst to obtain dichloro(4-chlorophenyl) borane, and carrying out acidic hydrolysis to obtain p-chlorophenylboronic acid. According to the method, p-chlorophenylboronic acid is synthesized by taking chlorobenzene as a raw material through a Friedel-Crafts reaction, and the method has theadvantages of novel synthesis route, simple and practical operation, easily available raw materials, low cost, environmental friendliness, and the like.
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Paragraph 0022-0029
(2020/04/22)
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- Pd- And Ni-Based Systems for the Catalytic Borylation of Aryl (Pseudo)halides with B2(OH)4
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Despite recent advancements in metal-catalyzed borylations of aryl (pseudo)halides, there is a continuing need to develop robust methods to access both early-stage and late-stage organoboron intermediates amendable for further functionalization. In particular, the development of general catalytic systems that operate under mild reaction conditions across a broad range of electrophilic partners remains elusive. Herein, we report the development and application of three catalytic systems (two Pd-based and one Ni-based) for the direct borylation of aryl (pseudo)halides using tetrahydroxydiboron (B2(OH)4). For the Pd-based catalyst systems, we have identified general reaction conditions that allow for the sequestration of halide ions through simple precipitation that results in catalyst loadings as low as 0.01 mol % (100 ppm) and reaction temperatures as low as room temperature. We also describe a complementary Ni-based catalyst system that employs simple unligated Ni(II) salts as an inexpensive alternative to the Pd-based systems for the borylation of aryl (pseudo)halides. Extrapolation of all three systems to a one-pot tandem borylation/Suzuki-Miyaura cross-coupling is also demonstrated on advanced intermediates and drug substances.
- Munteanu, Charissa,Spiller, Taylor E.,Qiu, Jun,Delmonte, Albert J.,Wisniewski, Steven R.,Simmons, Eric M.,Frantz, Doug E.
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p. 10334 - 10349
(2020/09/18)
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- Aryl boronic acid preparation method
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The invention belongs to the technical field of fine chemical engineering, and relates to an aryl boronic acid preparation method. In the prior art, aryl boronic acid as a novel safe and environmentally-friendly arylation reagent is widely used in scientific research and production of various fine chemicals containing aryl structures in the fields of medicines, pesticides, advanced materials and the like; and the aryl boronic acid compound preparation method reported in the disclosed literature has problems of harsh reaction conditions and high cost. A purpose of the invention is to provide amethod, wherein an aryl boron compound is formed by carrying out a reaction on a Grignard reagent and trialkyl borate under mild conditions, the composition of the aryl boron compound is converted from the main component diaryl borate into the main component aryl borate, and the aryl borate is hydrolyzed to obtain aryl boric acid, so that the preparation cost of the acyl aryl boric acid compound can be remarkably reduced, and the method has good practical application prospect.
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Paragraph 0033-0036; 0041
(2020/01/25)
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- Preparation method of 4-chlorophenylboronic acid
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The invention belongs to the technical field of organic synthesis and particularly relates to a preparation method of 4-chlorophenylboronic acid. The preparation method has the advantages that reaction conditions are optimized, the used raw materials are economical, low raw material cost is achieved, the mixed solvent of toluene and tetrahydrofuran is used to replace a single tetrahydrofuran solvent, p-dichlorobenzene replaces p-chlorobromobenzene to serve as the main raw material of Grignard reaction, discharge in water is achieved through condensation reaction with trimethyl borate or tributyl borate and post-treatment, raw material and solvent costs are saved greatly, yield is increased, and the preparation method is high in yield, low in cost, evident in competitive advantage and convenient to achieve industrial production.
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Paragraph 0029-0030
(2019/08/07)
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- Magnesium promoted autocatalytic dehydrogenation of amine borane complexes: A reliable, non-cryogenic, scalable access to boronic acids
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Owing to the unusual reactivity of dialkylamine-borane complexes, a methodology was developed to simply access boronic acids. The intrinsic instability of magnesium aminoborohydride was tweaked into a tandem dehydrogenation borylation sequence. Proceeding via an autocatalytic cycle, amineborane dehydrogenation was induced by a variety of Grignard reagents. Overall, addition of the organomagnesium species onto specially designed dialkylamine-borane complexes led to a variety of boronic acids in high yields. In addition, the reaction can be performed under Barbier conditions, on a large scale.
- Marciasini, Ludovic D.,Richard, Jimmy,Cacciuttolo, Bastien,Sartori, Guillaume,Birepinte, Melodie,Chabaud, Laurent,Pinet, Sandra,Pucheault, Mathieu
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p. 164 - 171
(2018/12/05)
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- Method for preparing chlorophenylboronic acid
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The invention discloses a method for preparing chlorophenylboronic acid. The method has the advantages that existing Grignard reagent processes are improved, Grignard reaction and substitution reaction are combined with each other and are carried out at a step, accordingly, ultralow-temperature control can be omitted, energy consumption can be obviously reduced, the operation difficulty can be obviously lowered, byproducts can be reduced, and the yield of target products can be increased.
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Paragraph 0015
(2018/11/03)
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- Copper-Catalyzed Monoorganylation of Trialkyl Borates with Functionalized Organozinc Pivalates
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Organozinc pivalates, a recently developed air- and moisture-stable organozinc species, were found for the first time as excellent organometallic species in the monoorganylation of trialkyl borates whereby boronic acids were prepared in high yields. The significant advantage of organozinc pivalates over another previously employed organometallic reagents, e. g., organolithium reagents, Grignard reagents and organozinc halides, is that the generation of multiorganylation byproducts such as borinic acids and trialkylboranes were completely suppressed. Additionally, the in situ generated boronates could be directly arranged into Suzuki-Miyaura type cross-coupling reactions to produce biaryls in high yields.
- Fu, Ying,Gou, Bei-Lei,Shi, Chun-Zhao,Du, Zhengyin,Shen, Tong
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p. 4253 - 4257
(2018/09/18)
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- Efficient Synthesis of Aryl Boronates via Cobalt-Catalyzed Borylation of Aryl Chlorides and Bromides
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An efficient catalytic system based on a Co(II)-NHC precursor has been developed for the cross coupling of bis(pinacolato)diboron with aryl halides including aryl chlorides, affording the aryl boronates in good to excellent yields. A wide range of functional groups are tolerated under mild reaction conditions. The reaction shows excellent chemoselectivity for bromide over chloride. Preliminary mechanistic investigations show that the catalytic cycle may rely on a cobalt(I)-(III) redox couple.
- Verma, Piyush Kumar,Mandal, Souvik,Geetharani
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p. 4049 - 4054
(2018/05/22)
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- Bedford-type palladacycle-catalyzed miyaura borylation of aryl halides with tetrahydroxydiboron in water
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A mild aqueous protocol for palladium catalyzed Miyaura borylation of aryl iodides, aryl bromides and aryl chlorides with tetrahydroxydiboron (BBA) as a borylating agent is developed. The developed methodology requires low catalyst loading of Bedford-type palladacycle catalyst (0.05 mol %) and works best under mild reaction conditions at 40 °C in short time of 6 h in water. In addition, our studies show that for Miyaura borylation using BBA in aqueous condition, maintaining a neutral reaction pH is very important for reproducibility and higher yields of corresponding borylated products. Moreover, our protocol is applicable for a broad range of aryl halides, corresponding borylated products are obtained in excellent yields up to 93% with 29 examples demonstrating its broad utility and functional group tolerance.
- Zernickel, Anna,Du, Weiyuan,Ghorpade, Seema A.,Sawant, Dinesh N.,Makki, Arwa A.,Sekar, Nagaiyan,Eppinger, J?rg
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p. 1842 - 1851
(2018/02/23)
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- Development of a Concise Multikilogram Synthesis of LPA-1 Antagonist BMS-986020 via a Tandem Borylation-Suzuki Procedure
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The process development for the synthesis of BMS-986020 (1) via a palladium catalyzed tandem borylation/Suzuki reaction is described. Evaluation of conditions culminated in an efficient borylation procedure using tetrahydroxydiboron followed by a tandem Suzuki reaction employing the same commercially available palladium catalyst for both steps. This methodology addressed shortcomings of early synthetic routes and was ultimately used for the multikilogram scale synthesis of the active pharmaceutical ingredient 1. Further evaluation of the borylation reaction showed useful reactivity with a range of substituted aryl bromides and iodides as coupling partners. These findings represent a practical, efficient, mild, and scalable method for borylation.
- Smith, Michael J.,Lawler, Michael J.,Kopp, Nathaniel,McLeod, Douglas D.,Davulcu, Akin H.,Lin, Dong,Katipally, Kishta,Sfouggatakis, Chris
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p. 1859 - 1863
(2017/11/24)
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- Importance of 5/6-aryl substitution on the pharmacological profile of 4?-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1?-biphenyl]-2-carboxylic acid derived PPARγ agonists
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In this structure-activity relationship study, the influence of aryl substituents at position 5 or 6 on the pharmacological profile of the partial PPARγ agonist 4‘-((2-propyl-1H-benzo[d]imidazol-1-yl)methyl)-[1,1‘-biphenyl]-2-carboxylic acid was investigated. This lead was previously identified as the essential part of telmisartan to induce PPARγ activation. Para-OCH3-phenyl substitution strongly increased potency and efficacy independent of the position. Both compounds represent full agonists because of strong hydrophobic contacts with the amino acid Phe363 in the ligand binding domain. Partial agonists with higher potency than telmisartan or the lead were obtained with OH or Cl substituents at the phenyl ring. Molecular modeling suggested additional hydrogen or halogen bonds with Phe360 located at helix 7. It is assumed that these interactions fix helix 7, thereby promoting a partial agonist conformation of the receptor. The theoretical considerations correlate very well with the results from the luciferase transactivation assay using hPPARγ-LBD as well as those from a time-resolved fluorescent resonance energy transfer (TR-FRET) assay in which the coactivator (TRAP220, PGC-1α) recruitment and corepressor (NCoR1) release pattern was investigated.
- Obermoser, Victoria,Mauersberger, Robert,Schuster, Daniela,Czifersky, Monika,Lipova, Marina,Siegl, Monika,Kintscher, Ulrich,Gust, Ronald
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supporting information
p. 590 - 603
(2016/12/09)
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- Scalable, Metal- and Additive-Free, Photoinduced Borylation of Haloarenes and Quaternary Arylammonium Salts
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We report herein a simple, metal- and additive-free, photoinduced borylation of haloarenes, including electron-rich fluoroarenes, as well as arylammonium salts directly to boronic acids. This borylation method has a broad scope and functional group tolerance. We show that it can be further extended to boronic esters and carried out on gram scale as well as under flow conditions.
- Mfuh, Adelphe M.,Doyle, John D.,Chhetri, Bhuwan,Arman, Hadi D.,Larionov, Oleg V.
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supporting information
p. 2985 - 2988
(2016/03/19)
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- Asymmetric Arylation of Imines Catalyzed by Heterogeneous Chiral Rhodium Nanoparticles
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Asymmetric arylation of aldimines catalyzed by heterogeneous chiral rhodium nanoparticles has been developed. The reaction proceeded in aqueous media without significant decomposition of the imines by hydrolysis to afford chiral (diarylmethyl)amines in high yields with outstanding enantioselectivities. This catalyst system exhibited the highest turnover number (700) in heterogeneous catalysts reported to date for these reactions. The reusability of the catalyst was also demonstrated.
- Yasukawa, Tomohiro,Kuremoto, Tatsuya,Miyamura, Hiroyuki,Kobayashi, Sh?
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supporting information
p. 2716 - 2718
(2016/06/15)
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- Iron catalysis and water: A synergy for refunctionalization of boron
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A new catalytic system has been optimized to promote the conversion of boron species into others. FeCl3 associated with imidazole and water favors boron refunctionalization under mild conditions. Georg Thieme Verlag Stuttgart New York.
- Wood, John L.,Marciasini, Ludovic D.,Vaultier, Michel,Pucheault, Mathieu
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supporting information
p. 551 - 555
(2014/03/21)
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- Methanol-promoted borylation of arylamines: A simple and green synthetic method to arylboronic acids and arylboronates
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A Sandmeyer borylation of arylamines via a SN2Ar pathway promoted by methanol with sodium nitrite and hydrochloric acid as diazotization agent has been developed, which provide a simple and green synthetic method to arylboronic acids and arylboronates. Georg Thieme Verlag Stuttgart New York.
- Zhao, Cong-Jun,Xue, Dong,Jia, Zhi-Hui,Wang, Chao,Xiao, Jianliang
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p. 1577 - 1584
(2014/07/08)
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- An easy route to (hetero)arylboronic acids
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An unprecedented spontaneous reactivity between diazonium salts and diboronic acid has been unveiled, leading to a versatile arylboronic acid synthesis directly from (hetero)arylamines. This fast reaction (35 min overall) tolerates a wide range of functional groups and is carried out under very mild conditions. The radical nature of the reaction mechanism has been investigated.
- Erb, William,Hellal, Akila,Albini, Mathieu,Rouden, Jacques,Blanchet, Jerome
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p. 6608 - 6612
(2014/06/09)
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- Sequential one-pot access to molecular diversity through aniline aqueous borylation
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On the basis of our recently reported aniline aqueous borylation, molecular diversity was achieved in a one-pot process by combining other reactions such as esterification, Suzuki-Miyaura coupling, hydrogenolysis, or Petasis borono-Mannich.
- Erb, William,Albini, Mathieu,Rouden, Jacques,Blanchet, Jrme
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p. 10568 - 10580
(2015/01/08)
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- Synthesis and mesomorphic properties of laterally fluorinated alkyl 4′′-alkylterphenyl-4-yl carbonate liquid crystals
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Fifteen series of homologues of a variety of mono-, di- and trifluorosubstituted alkyl 4′′-alkylterphenyl-4-yl carbonates have been synthesized and their mesomorphic properties have been determined. From among 95 prepared compounds, 40 pure nematogens have been found, as well as 55 mesogens with orthogonal and tilted smectic phases in broad temperature ranges. The type and combination of the LC phase strongly depend on the position and number of the fluorine atoms. Physical properties and correlations between the molecular core fluorosubstitution, the length of the terminal chains and the type and sequence of the liquid crystalline phases, have been determined. The compounds are useful for the formulation of nematic mixtures as well as ferroelectric ones.
- Choluj, Artur,Kula, Przemyslaw,Dabrowski, Roman,Tykarska, Marzena,Jaroszewicz, Leszek
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p. 891 - 900
(2014/01/23)
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- Mn-catalyzed aromatic C-H alkenylation with terminal alkynes
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The first manganese-catalyzed aromatic C-H alkenylation with terminal alkynes is described. The procedure features an operationally simple catalyst system containing commercially available MnBr(CO)5 and dicyclohexylamine (Cy2NH). The reaction occurs readily in a highly chemo-, regio-, and stereoselective manner delivering anti-Markovnikov E-configured olefins in high yields. Experimental study and DFT calculations reveal that (1) the reaction is initiated by a C-H activation step via the cooperation of manganese and base; (2) manganacycle and alkynylmanganese species are the key reaction intermediates; and (3) the ligand-to-ligand H-transfer and alkynyl-assisted C-H activation are the key steps rendering the reaction catalytic in manganese.
- Zhou, Bingwei,Chen, Hui,Wang, Congyang
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supporting information
p. 1264 - 1267
(2013/03/14)
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- Synthesis of phenylboronic acids in continuous flow by means of a multijet oscillating disc reactor system operating at cryogenic temperatures
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A multijet oscillating disk (MJOD) millireactor system suitable for operating at cryogenic temperatures has been developed, assembled, and investigated. This new reactor system (cryoMJOD) was realized with the purpose to prepare various phenylboronic acids in a continuous two (three)-step telescoped synthetic process at temperatures in the interval -50 to -75 °C. In this process, n-butyllithium was reacted with a phenylbromide to provide the corresponding phenyllithium derivative, whereupon a borate was added under the formation of target product phenylboronic acid in good selectivity and medium-to-good yield (50-75%). These results were competitive with results previously revealed in the literature. The residence times of the telescoped two-step process were considerably shorter compared to those of batch mode operations for the identical syntheses. The flow process was optimized by means of statistical experimental design and multivariate regression, upon which the process was utilized for the production of a series of phenylboronic acid derivatives, all in medium-to-good yield. One of the substrates, 4-methoxyphenylboronic acid, was submitted for throughput improvements, resulting in a process with capability to produce the product phenylboronic acid in a quantity of 2.0 kg × day-1.
- Sleveland, Dagfinn,Bjorsvik, Hans-Rene
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experimental part
p. 1121 - 1130
(2012/08/27)
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- Lithium aminoborohydrides 17. Palladium catalyzed borylation of aryl iodides, bromides, and triflates with diisopropylaminoborane prepared from lithium diisopropylaminoborohydride
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The Alcaraz-Vaultier borylation of aryl halides and triflates is reported utilizing diisopropylaminoborane (BH2N(iPr)2) prepared from the corresponding lithium aminoborohydride (LAB reagent). BH 2N(iPr)2, prepared by reacting lithium diisopropylaminoborohydride with trimethylsilyl chloride, provided the most consistent isolated yields from this reaction. Catalytic amounts of palladium dichloride produced the highest yields from aryl iodides, while catalytic tris(dibenzylideneacetone)dipalladium(chloroform) provided the best yields for aryl bromides and triflates. This route to boronic acids is mild enough to tolerate various functionalities and for the first time employs aryl triflates as substrates for the Alcaraz-Vaultier borylation. In addition, it was found that both boronic acid and ester compounds could be isolated from the reaction mixture utilizing simple work-up procedures. Treatment of the reaction intermediate with an acid/base work-up provided the corresponding boronic acid, while treating the same intermediate with a diol, such as neopentyl glycol, afforded the corresponding boronic ester.
- Haddenham, Dustin,Bailey, Christopher L.,Vu, Chau,Nepomuceno, Gabby,Eagon, Scott,Pasumansky, Lubov,Singaram, Bakthan
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experimental part
p. 576 - 583
(2011/03/18)
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- Highly efficient one-pot access to functionalized arylboronic acids via noncryogenic bromine/magnesium exchanges
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A general and convenient protocol for the electrophilic borylation of aryl Grignard reagents prepared from arylbromides by direct insertion of magnesium in the presence of LiCl or by Mg/Br exchange with iPrMgCl?LiCl has been developed. Various aryl boronic acids were synthesized in a straightforward manner in excellent yields at 0 °C.
- Leermann, Timo,Leroux, Frederic R.,Colobert, Francoise
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supporting information; experimental part
p. 4479 - 4481
(2011/10/09)
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- A recyclable Au(I) catalyst for selective homocoupling of arylboronic acids: Significant enhancement of nano-surface binding for stability and catalytic activity
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Au nanoparticles stabilized by polystyrene-co-polymethacrylic acid microspheres (PS-co-PMAA) were prepared and characterized via X-ray diffraction (XRD), and transmission electron microscope (TEM). The Au nanoparticles supported on the microspheres showed highly selective catalytic activity for homo-coupling reactions of arylboronic acids in a system of aryl-halides and arylboronic acids. X-ray photoelectron spectroscopy (XPS) spectra of the catalyst shows large amounts of Au(l) complexes band to the surface of the Au nanoparticles, which contributes to the selective homocoupling of the arylboronic acids. More importantly, this supported Au complex is a highly recyclable catalyst. The supported Au catalyst can be recycled and reused at least 6 times for a phenylboronic acid reactant, whereas the parent complex shows very low catalytic activity for this compound. The high catalytic activity of this material is attributed to: (1) the high surface to volume ratio which leads to more active sites being exposed to reactants; (2) the strong surface binding of the Au nanoparticle to the Au(1) complexes, which enhances both the stability and the catalytic activity of these complexes. Copyright
- Zhang, Xin,Zhao, Haitao,Wang, Jianhui
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experimental part
p. 5153 - 5160
(2011/12/15)
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- THIENOPYRIDAZINE COMPOUNDS, THEIR PREPARATIONS, PHARMACEUTICAL COMPOSITIONS AND USES
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The present invention relates to thienopyridazine compounds of formula (I), their pharmaceutically acceptable salts or hydrates, wherein R1 and R2 are independently H or C1-4 alkyl, R3 is a saturated or unsaturated 5- or 6- membered ring containing N, S or O, or its optical isomers, R4 is a halophenyl monosubstituted or disubstituted at any position. The present invention provides the preparation methods of these compounds, pharmaceutical compositions containing these compounds and the uses of these compounds, particularly in treating cancer.
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Page/Page column 26
(2010/11/03)
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- Efficient hydrolysis of organotrifluoroborates via silica gel and water
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(Chemical Equation Presented) A general, mild, and efficient method for the hydrolysis of organotrifluoroborates to unveil boronic acids using silica gel and H2O was developed. This method proved to be tolerant of a broad range of aryl-, heteroaryl-, alkenyl-, and alkyltrifluoroborates as well as structurally diverse aminomethylated organotrifluoroborates.As anticipated, electron-rich substrates provided the corresponding boronic acids more readily than electron-poor substrates, owing to the resonance-stabilized difluoroborane intermediate. The method developed was expanded further for the conversion of organotrifluoroborates to the corresponding boronate esters. 2009 American Chemical Society.
- Molander, Gary A.,Cavalcanti, Livia N.,Canturk, Belgin,Pan, Po-Shen,Kennedy, Lauren E.
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supporting information; experimental part
p. 7364 - 7369
(2010/01/16)
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- Novel Compounds and Therapeutic Use Thereof for Protein Kinase Inhibition
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Novel compound having the following formula: Also disclosed are a pharmaceutical compositions comprising the same, methods for treating cancer using the same, and methods for the synthesis of the same. The novel compounds of the present invention are found to inhibit protein kinases, especially Checkpoint kinase Chk1/Chk2.
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Page/Page column 12; 16
(2009/12/02)
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- Identification of a butyrophenone analog as a potential atypical antipsychotic agent: 4-[4-(4-Chlorophenyl)-1,4-diazepan-1-yl]-1-(4-fluorophenyl)butan-1-one
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The synthesis and exploration of novel butyrophenones have led to the identification of a diazepane analogue of haloperidol, 4-[4-(4-chlorophenyl)-1,4-diazepan-1-yl]-1-(4-fluorophenyl)butan-1-one (compound 13) with an interesting multireceptor binding profile. Compound 13 was evaluated for its binding affinities at DA subtype receptors, 5HT subtype receptors, H-1, M-1 receptors and at NET, DAT, and SERT transporters. At each of these receptors, compound 13 was equipotent or better than several of the standards currently in use. In in vivo mouse and rat models to evaluate its efficacy and propensity to elicit catalepsy and hence EPS in humans, compound 13 showed similar efficacy as clozapine and did not produce catalepsy at five times its ED50 value.
- Ablordeppey, Seth Y.,Altundas, Ramazan,Bricker, Barbara,Zhu, Xue Y.,Suresh Kumar, Eyunni V.K.,Jackson, Tanise,Khan, Abdul,Roth, Bryan L.
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p. 7291 - 7301
(2008/12/23)
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- Palladium-catalyzed cross-coupling of N-benzenesulfonyl-3,4-dibromopyrrole and its application to the total syntheses of lamellarins O, P, Q, and R
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Palladium-catalyzed Suzuki-Miyaura coupling of N-benzenesulfonyl-3,4-dibromopyrrole with a variety of arylboronic acids gave the corresponding 3,4-diarylpyrroles in high yields. The 3,4-differentially arylated pyrroles could also be prepared by stepwise cross-coupling approach. The total syntheses of lamellarins O, P, Q, and R have been achieved by using the cross-coupling and the directed lithiation as key reactions.
- Fukuda, Tsutomu,Sudo, Ei-ichi,Shimokawa, Kozue,Iwao, Masatomo
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p. 328 - 338
(2008/04/01)
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- Benzoxepin-derived estrogen receptor modulators: A novel molecular scaffold for the estrogen receptor
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We present and examine the efficacy of a novel benzoxepin-based scaffold for modulation of the human estrogen receptor. Receptor tolerance of this new molecular scaffold is examined through presentation of experimentally determined antiproliferative effects on human MCF-7 breast tumor cells and measured binding affinities. The effect of functional group substitution on the benzoxepin scaffold is explored through a brief computational structure - activity relationship investigation with molecular simulation.
- Lloyd, David G.,Hughes, Rosario B.,Zisterer, Daniela M.,Williams, D. Clive,Fattorusso, Caterina,Catalanotti, Bruno,Campiani, Giuseppe,Meegan, Mary J.
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p. 5612 - 5615
(2007/10/03)
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- Thrombopoietin mimetics
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Invented are non-peptide TPO mimetics. Also invented is a method of treating thrombocytopenia, in a mammal, including a human, in need thereof which comprises administering to such mammal an effective amount of a selected substituted naphthimidazole derivative.
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- Formation of boroxine: Its stability and thermodynamic parameters in solution
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Condensation of three boronic acids proceeding at room temperature gave their corresponding boroxines; NMR spectral measurements revealed that the reaction was reversible at room temperature, that electron-donating groups supported the formation of boroxine, and that entropically driven forces promoted the formation of boroxine in solution.
- Tokunaga, Yuji,Ueno, Hiroki,Shimomura, Youji,Seo, Toshihiro
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p. 787 - 790
(2007/10/03)
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- An improved protocol for the preparation of 3-pyridyl- and some arylboronic acids
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3-Pyridylboronic acid was prepared in high yield and bulk quantity from 3-bromopyridine via a protocol of lithium-halogen exchange and "in situ quench". This technique was further studied and evaluated on other aryl halides in the preparation of arylboronic acids.
- Li, Wenjie,Nelson, Dorian P.,Jensen, Mark S.,Hoerrner, R. Scott,Cai, Dongwei,Larsen, Robert D.,Reider, Paul J.
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p. 5394 - 5397
(2007/10/03)
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- THE REACTIONS OF DIBORANE WITH ARYL-ORGANOTIN COMPOUNDS
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A number of tetraaryltin compounds, Ar4Sn (where Ar = phenyl, o- and p-tolyl, and p-chlorophenyl) and tryphenyltin compounds, PH3SnX (where X = Cl, H, OH, OCOCH3 and OCOCF3) have been treated with diborane in tetrahydrofuran.Transmetallation occurs in which one or more aryl groups are transferred to boron.The organoboron intermediates give phenols upon oxidation and boronic and borinic acids upon hydrolysis.Pyridine complexes of organoboranes have also been isolated.
- Pickles, G. M.,Spencer, T.,Thorpe, F. G.,Chopa, A. B.,Podesta, J. C.
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- SYNTHESE UND THERMISCH INDUZIERTE UMLAGERUNG DER DIARYLBORCHELATE VON N-(2-HYDROXYALKYL)-N,N-DIALKYLAMIN-N-OXIDEN
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Various diarylboron chelates of the cyclic B,N-betaine type (2,7,11) are synthesized from N-(2-hydroxyalkyl)-N,N-dialkylamine-N-oxides (1) and diarylboron reagents.They are rearranged in a thermally induced intramolecular redox reaction, during which the N-oxide is deoxygenated and the borinic acid moiety is oxidized to the state of boronic acid.The rearrangement products 3, 8 and 12 are converted to new B,N-betaine type chelates 5 and 9 by re-chelation with N-oxides (1).
- Kliegel, Wolfgang,Ahlenstiel, Eckart
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p. 173 - 188
(2007/10/02)
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