- Reductive Electrophotocatalysis: Merging Electricity and Light to Achieve Extreme Reduction Potentials
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We describe a new electrophotocatalytic strategy that harnesses the power of light and electricity to generate an excited radical anion with a reducing potential of -3.2 V vs SCE, which can be used to activate substrates with very high reduction potentials (Ered ≈ -1.9 to -2.9 V). The resultant aryl radicals can be engaged in various synthetically useful transformations to furnish arylboronate, arylstannane, and biaryl products.
- Kim, Hyunwoo,Kim, Hyungjun,Lambert, Tristan H.,Lin, Song
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supporting information
p. 2087 - 2092
(2020/02/04)
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- Synthesis of Arylstannanes via Palladium-Catalyzed Decarbonylative Coupling of Aroyl Fluorides
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Aryl stannanes are valuable precursors in organic transformations, but their synthetic methods are limited. Here we present a Pd-catalyzed decarbonylative stannylation of acid fluorides in the absence of exogenous base. Various aryl stannanes were efficiently prepared from bench-stable transition metal catalyst and ligand with broad functional group compatibility and substrate scope including natural products and pharmaceuticals. This protocol was also successfully used to a late-stage diversification of an existing uricosuric drug probenecid. (Figure presented.).
- Kayumov, Muzaffar,Zhao, Jian-Nan,Mirzaakhmedov, Sharafitdin,Wang, Dong-Yu,Zhang, Ao
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supporting information
p. 776 - 781
(2019/11/14)
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- Visible-Light-Driven Synthesis of Arylstannanes from Arylazo Sulfones
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The visible-light-driven preparation of (hetero)aryl stannanes was carried out under both photocatalyst- and metal-free conditions via irradiation of arylazo sulfones in the presence of hexaalkyldistannanes. The reaction shows a high efficiency and a wide substrates scope. The resulting crude organotin derivatives can be directly employed in a Stille protocol.
- Lian, Chang,Yue, Guanglu,Mao, Jinshan,Liu, Danyang,Ding, Yi,Liu, Zerong,Qiu, Di,Zhao, Xia,Lu, Kui,Fagnoni, Maurizio,Protti, Stefano
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supporting information
p. 5187 - 5191
(2019/07/03)
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- Synthesis of Aryl Trimethylstannane via BF3·OEt2-Mediated Cross-Coupling of Hexaalkyl Distannane Reagent with Aryl Triazene at Room Temperature
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BF3·OEt2-mediated cross-coupling of (SnMe3)2 with aryl triazene offers a new strategy for the synthesis of aryl stannane. A variety of synthetically useful aryl trimethylstannanes were produced in moderate to good yields with this metal-free approach. One-pot sequential Stille cross-coupling with different aryl bromides provides a short entry to both symmetrical and unsymmetrical biaryl compounds.
- Mao, Shuai,Chen, Zhengkai,Wang, Lu,Khadka, Daulat Bikram,Xin, Minhang,Li, Pengfei,Zhang, San-Qi
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p. 463 - 471
(2019/01/10)
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- SUBSTITUTED BENZAZINONES AS ANTIBACTERIAL COMPOUNDS
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The present invention relates to LpxC antibacterial compounds of Formula (1A), corresponding pharmaceutically acceptable salts thereof, corresponding pharmaceutical compositions:, compound preparation, treatment methods and uses for bacterial infections, especially those caused by gram-negative bacteria.
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Page/Page column 253
(2017/07/14)
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- A practical method for the preparation of 18F-labeled aromatic amino acids from nucleophilic [18F]fluoride and stannyl precursors for electrophilic radiohalogenation
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In a recent contribution of Scott et al., the substrate scope of Cu-mediated nucleophilic radiofluorination with [18F]KF for the preparation of 18F-labeled arenes was extended to aryland vinylstannanes. Based on these findings, the potential of this reaction for the production of clinically relevant positron emission tomography (PET) tracers was investigated. To this end, Cu-mediated radiofluorodestannylation using trimethyl(phenyl)tin as a model substrate was re-evaluated with respect to different reaction parameters. The resulting labeling protocol was applied for 18F-fluorination of different electron-rich, -neutral and -poor arylstannyl substrates in RCCs of 16-88%. Furthermore, this method was utilized for the synthesis of 18F-labeled aromatic amino acids from additionally N-Boc protected commercially available stannyl precursors routinely applied for electrophilic radiohalogenation. Finally, an automated synthesis of 6-[18F]fluoro-L-m-tyrosine (6-[18F]FMT), 2-[18F]fluoro-L-tyrosine (2-[18F]F-Tyr), 6-[18F]fluoro-L-3, 4-dihydroxyphenylalanine (6-[18F]FDOPA) and 3-O-methyl-6-[18F]FDOPA ([18F]OMFD) was established furnishing these PET probes in isolated radiochemical yields (RCYs) of 32-54% on a preparative scale. Remarkably, the automated radiosynthesis of 6-[18F]FDOPA afforded an exceptionally high RCY of 54 5% (n = 5).
- Zarrad, Fadi,Zlatopolskiy, Boris D.,Krapf, Philipp,Zischler, Johannes,Neumaier, Bernd
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- Synthesis of aryl trimethylstannanes from aryl halides: An efficient photochemical method
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An efficient transition-metal-free photochemical method featuring excellent functional group tolerance, mild reaction conditions and short reaction times has been discovered and developed for the synthesis of (hetero)aryl trimethylstannanes from (hetero)aryl halides. A photo-initiated radical chain mechanism was proposed based on preliminary mechanistic studies.
- Chen, Kai,He, Pei,Zhang, Shuai,Li, Pengfei
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p. 9125 - 9128
(2016/07/21)
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- Copper-Mediated Radiofluorination of Arylstannanes with [18F]KF
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A copper-mediated nucleophilic radiofluorination of aryl- and vinylstannanes with [18F]KF is described. This method is fast, uses commercially available reagents, and is compatible with both electron-rich and electron-deficient arene substrates. This method has been applied to the manual synthesis of a variety of clinically relevant radiotracers including protected [18F]F-phenylalanine and [18F]F-DOPA. In addition, an automated synthesis of [18F]MPPF is demonstrated that delivers a clinically validated dose of 200 ± 20 mCi with a high specific activity of 2400 ± 900 Ci/mmol.
- Makaravage, Katarina J.,Brooks, Allen F.,Mossine, Andrew V.,Sanford, Melanie S.,Scott, Peter J. H.
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supporting information
p. 5440 - 5443
(2016/11/04)
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- 1,2-AZABORINE COMPOUNDS AND SYNTHESIS
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A compound, or a pharmaceutically acceptable salt or ester thereof, having a structure of formula (I), wherein R1 is a substituted aryl or an optionally-substituted heteroaryl, provided that the heteroaryl is not pyridyl or azaborine; and each
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Page/Page column 15-16
(2014/02/16)
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- Synthesis of aryl trimethylstannanes from aryl amines: A sandmeyer-type stannylation reaction
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Sandmeyer-type stannylation: Stille coupling is one of the most powerful coupling reactions for C-C bond formation, whereas there are only limited methods to access aryl stannane compounds. A mild stannylation process based on a Sandmeyer-type transformation using aromatic amines as the starting materials is described. DCE: 1,2-dichloroethane. Copyright
- Qiu, Di,Meng, He,Jin, Liang,Wang, Shuai,Tang, Shengbo,Wang, Xi,Mo, Fanyang,Zhang, Yan,Wang, Jianbo
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supporting information
p. 11581 - 11584
(2013/11/06)
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- Synthesis of thiophene 1,1-dioxides and tuning their optoelectronic properties
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A 2,5-bis(tributylstannyl)thiophene 1,1-dioxide was prepared from 2,5-bis(trimethylsilyl)thiophene 1,1-dioxide, bis(tributyltin) oxide, and tetrabutylammonium fluoride (TBAF). The 2,5-bis(tributylstannyl)thiophene 1,1-dioxide and a 2,5-diiodothiophene 1,1
- Tsai, Chia-Hua,Chirdon, Danielle N.,Maurer, Andrew B.,Bernhard, Stefan,Noonan, Kevin J. T.
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supporting information
p. 5230 - 5233
(2013/11/06)
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- Rhodium-catalyzed boron arylation of 1,2-azaborines
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A Sn-phony in B! BN isosteres of biphenyl compounds are prepared through Rh-catalyzed cross-coupling between 2-chloro-1,2-azaborines and arylstannanes (see scheme). The synthetic method should enable investigations of structure-activity relationships (SAR
- Rudebusch, Gabriel E.,Zakharov, Lev N.,Liu, Shih-Yuan
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supporting information
p. 9316 - 9319
(2013/09/12)
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- An enthalpic basis of additivity in biphenyl hydroxamic acid ligands for stromelysin-1
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Fragment based drug discovery remains a successful tool for pharmaceutical lead discovery. Although based upon the principle of thermodynamic additivity, the underlying thermodynamic basis is poorly understood. A thermodynamic additivity analysis was performed using stromelysin-1 and a series of biphenyl hydroxamate ligands identified through fragment additivity. Our studies suggest that, in this instance, additivity arises from enthalpic effects, while interaction entropies are unfavorable; this thermodynamic behavior is masked by proton transfer. Evaluation of the changes in constant pressure heat capacities during binding suggest that solvent exclusion from the binding site does not account for the dramatic affinity enhancements observed.
- Wilfong, Erin M.,Du, Yu,Toone, Eric J.
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supporting information
p. 6521 - 6524
(2012/11/07)
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- Thiadiazole fused indolo[2,3-a]carbazoles as new building blocks for optoelectronic applications
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New indolo[2,3-a][1,2,5]thiadiazolo[3,4-c]carbazoles including functional groups (halide or hydroxyl groups) on the meta positions relative to the nitrogen atoms which are known to be the most conjugated, have been synthesized following two synthetic rout
- Biniek, Laure,Bulut, Ibrahim,Lévêque, Patrick,Heiser, Thomas,Leclerc, Nicolas
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scheme or table
p. 1811 - 1814
(2011/05/05)
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- FLUORINATION OF ORGANIC COMPOUNDS
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Methods for fluorinating organic compounds are described herein.
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Page/Page column 32
(2010/07/10)
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- On the reaction of 4-substituted trimethyltin aromatics with perchlorylfluoride
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To evaluate the suitability of [18F]perchorylfluoride [18F]FClO3 as an electrophilic fluorination agent for the preparation of radiopharmaceuticals, the reactivity non-radioactive FClO3 towards 4-substituted trimethyltin aromatic compounds was studied. Contrary to the expectation, an electrophilic fluorination of the aromatic nucleus did not occur. The reaction of perchlorylfluoride with aromatic trimethylstannyl compounds resulted in the formation of trimethyltin fluoride and the respective destannylated aromatics in variable yields.
- Hiller, Achim,Patt, J?rg T.,Steinbach, J?rg
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p. 3737 - 3742
(2007/10/03)
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- Phenols as starting materials for the synthesis of arylstannanes via SRN11
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Phenols are converted into aryl diethyl phosphate esters (ArDEP), which on reaction with sodium trimethylstannide (1) or sodium triphenylstannide (2) in liquid ammonia afford arylstannanes by the SRN1 mechanism. Thus, the photostimulated reaction of phenylDEP (3), (4-methoxyphenyl)DEP (4), (4-biphenyl)DEP (5), (1-naphthyl)DEP (6), (2-naphthyl)DEP (7), and 2- (34), 3- (32), and (4-pyridyl)DEP (35) with 1 leads to monostannylated product in fair to excellent yields (20-98%). Also, substrates containing two or three leaving groups react with 1 under irradiation, affording the corresponding di- or tristannylated aryl compounds. With tetraethyl m-phenylene bisphosphate (15), tetraethyl p-phenylene bisphosphate (21), (4-chlorophenyl)DEP (22), and 1,3,5-tris(diethylphospho)benzene (30), the di- or trisubstitution products 1,3-bis(trimethylstannyl)benzene (19) (79%), 1,4-bis(trimethylstannyl)benzene (23) (95 and 97%), and 1,3,5-tris(trimethylstannyl)benzene (31) (57%) are obtained, respectively. Also, the reaction of 6 and 7 with 2 leads to substitution products in quantitative yields, and the reaction of 21, 22, and (4-bromophenyl)DEP (24) with 2 affords 1,4-bis(triphenylstannyl)benzene (38) in high yields (70-100%). On the other hand, the results obtained in the photostimulated reaction of 24 and (4-iodophenyl)DEP (25) with 1, as well as in the reaction of 25 with 2, clearly indicate a fast HME reaction.
- Chopa, Alicia B.,Lockhart, María T.,Dorn, Viviana B.
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p. 1425 - 1429
(2008/10/08)
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- Synthesis of arylstannanes from arylamines
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Arylamines have been converted into aryltrimethylammonium salts, which on reaction with sodium trimethylstannide (1) in liquid ammonia afford aryltrimethylstannanes by the SRN1 mechanism. With (4-methoxyphenyl)- (2), (1-naphthyl)- (4), phenyl- (6), (4-acetylphenyl)- (8), and (4-cyanophenyl)trimethylammonium salts (10) the substitution products are obtained in good to excellent yields (45-100%). Also, the photo-stimulated reaction of (2-pyridyl)trimethylammonium iodide (12) with 1 leads to the substitution product 13 (50%). With (4-chlorophenyl)trimethylammonium iodide (14) the disubstitution product 19 is obtained in 76% yield. On the other hand, the results obtained in the reaction of (4-bromophenyl)trimethylammonium iodide (15) with 1 clearly indicate a fast HME reaction in the dark. The ET process (SRN1) competes, although inefficiently, under irradiation.
- Chopa, Alicia B.,Lockhart, Maria T.,Silbestri, Gustavo
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p. 3358 - 3360
(2008/10/08)
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- Two-step synthesis of arylstannanes from phenols
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The reactions of a number of aryl diethyl phosphates (ArDEP) with (triphenylstannyl)sodium and (trimethylstannyl) sodium in liquid ammonia were studied. Results indicate that the conversion of phenols into the corresponding aryl diethyl phosphates followed by the S displacement with organotin anions is an excellent and convenient method for the synthesis of arylstannanes.
- Chopa, Alicia B.,Lockhart, Maria T.,Silbestri, Gustavo
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p. 2249 - 2250
(2008/10/08)
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- Synthesis of asymmetrical aryl-tin compounds by cleavage of alkyl-tin bonds with sodium metal in liquid ammonia followed by SRN1 reactions with chloroarenes
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One methyl-tin bond was selectively cleaved from aryltrimethyltin compounds by sodium metal in liquid ammonia. The triorganylstannyl anions thus obtained are arylated by chloroarenes by means of photostimulated SRN1 reactions. Such reactions ca
- Yammal, Carlos C.,Podesta, Julio C.,Rossi, Roberto A.
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- UROKINASE INHIBITORS
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Disclosed are benzothiophene and thienothiophene derivatives useful for inhibiting urokinase activity.
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- DIRECT STANNYLATION OF AROMATIC DERIVATIVES USING BIS(TRIMETHYLSTANNYL) SULPHIDE AND SODIUM
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The reaction of bis(trimethylstannyl) sulphide and sodium with toluene, m-xylene, p-xylene and thioanisole gives stannylation at the methyl group whereas anisole was stannylated at the aromatic nucleus with very high ortho selectivity
- Capozzi, Giuseppe,Menichetti, Stefano,Ricci, Alfredo,Taddei, Maurizio
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p. 721 - 722
(2007/10/02)
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- Reactions of Trialkylstannane Anions R3Sn- with Arylstannanes ArSnR'3
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The reactions of trialkylstannane anions R3Sn- with arylstannanes ArSnR'3 have been investigated; trialkylstannane anions with arylstannanes at 50 deg C gave substitution products ArSnR3 in good yields.Most of these substitution products are diverted to r
- Mochida, Kunio
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p. 3299 - 3306
(2007/10/02)
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- SYNTHESIS AND SPECTROSCOPIC CHARACTERISTICS OF ARYLTRIMETHYL-SILICON, -GERMANIUM, AND -TIN COMPOUNDS
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The synthesis and spectroscopic characteristics of 28 para-substituted aryltrimethyl-silicon, -germanium, and -tin compounds are described.The infrared spectra show characteristic bands at 1245-1165 (methyl bend), 840-765 (methyl rock), and 1105-1020 (in-plane aromatic H bend) cm-1; the frequency of the last band was found to depend on the sum of the aromatic substituent masses, the presence or absence of metallic constituents in the substituent having little influence.The mass spectral fragmentation patterns are interpreted in terms of localization of positive charge on the metal atom, with subsequent bond cleavage behavior which obeys the rules for mass spectra of carbon compounds.
- Moerlein, S. M.
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- SYNTHESIS OF ORGANOTRIALKYLSTANNANES. THE REACTION BETWEEN ORGANIC HALIDES AND HEXAALKYLDISTANNANES IN THE PRESENCE OF PALLADIUM COMPLEXES
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The aryl halides YC6H4X (X=Br or I) have been shown to react with the distannanes (R3Sn)2 (R=n-Bu or Me) in toluene in the presence of or to give the compounds YC6H4SnR3 for (a) R=n-Bu, Y=H, p-OMe, o-Me, p-Me, m-Cl, p-Cl, m-CN, p-COCH3 and m-NO2, and (b) R=Me, Y=H, p-OMe, p-Me, p-CN, p-COCH3, m-NO2 and p-NO2.Benzyl halides YC6H4CH2X (X=Cl or Br) similarly give YC6H4CH2SnR3 for (a) R=n-Bu, Y=H, m-OMe, p-OMe, m-Cl, m-CN, and m-NO2, and (b) R=Me, Y=m-Cl, m-CN, p-CN and m-NO2.These reactions are of special value as preparative procedures in cases in which Grignard or organolithium reagents cannot be used.Allyl chloride and bromide were likewise shown to react with (n-Bu3Sn)2 to give CH2=CHCH2SnBu3, but n-BuCl and n-BuBr gave only a trace of n-Bu4Sn.The mixed dimetallo species n-Bu3SnSiMe3 was shown to react with aryl bromides YC6H4Br (X=H, p-OMe, p-Me, or p-Cl) to give the arylsilicon compounds YC6H4SiMe3, with no aryltin products.
- Azizian, Hormoz,Eaborn, Colin,Pidcock, Alan
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