- Copper-catalyzed oxidative methylation of sulfonamides by dicumyl peroxide
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A novel and facile copper-catalyzed methylation of sulfonamides was herein demonstrated. The practical transformation took place readily under the oxidative conditions, and N-methyl amides (23 examples) were successfully furnished in high efficiency (up to 90% yields). Dicumyl peroxide was considered to act not only as the oxidant in the system, but also methyl donor for the methylation protocol.
- Che, Shiying,Zhu, Qiao,Luo, Zhenghong,Lian, Yan,Zhao, Zijian
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p. 935 - 942
(2021/01/05)
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- Time-Resolved EPR Revealed the Formation, Structure, and Reactivity of N -Centered Radicals in an Electrochemical C(sp3)-H Arylation Reaction
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Electrochemical synthesis has been rapidly developed over the past few years, while a vast majority of the reactions proceed through a radical pathway. Understanding the properties of radical intermediates is crucial in the mechanistic study of electroche
- Alhumade, Hesham,Gao, Renfei,Huang, Cunlong,Lei, Aiwen,Liu, Yichang,Liu, Zhao,Qi, Xiaotian,Shi, Biyin,Wang, Shengchun
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supporting information
p. 20863 - 20872
(2021/12/14)
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- N-Methylation of Amines with Methanol in the Presence of Carbonate Salt Catalyzed by a Metal-Ligand Bifunctional Ruthenium Catalyst [(p-cymene)Ru(2,2′-bpyO)(H2O)]
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A ruthenium complex [(p-cymene)Ru(2,2′-bpyO)(H2O)] was found to be a general and efficient catalyst for the N-methylation of amines with methanol in the presence of carbonate salt. Moreover, a series of sensitive substituents, such as nitro, ester, cyano, and vinyl groups, were tolerated under present conditions. It was confirmed that OH units in the ligand are crucial for the catalytic activity. Notably, this research exhibited the potential of metal-ligand bifunctional ruthenium catalysts for the hydrogen autotransfer process.
- Liu, Peng,Tung, Nguyen Thanh,Xu, Xiangchao,Yang, Jiazhi,Li, Feng
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p. 2621 - 2631
(2021/02/27)
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- Recyclable covalent triazine framework-supported iridium catalyst for the N-methylation of amines with methanol in the presence of carbonate
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An iridium complex Cp*Ir@CTF, which is synthesized by the coordinative immobilization of [Cp*IrCl2]2 on a functionalized covalent triazine framework (CTF), was found to be a general and highly efficient catalyst for the N-methylation of amines with methanol in the presence of carbonate. Under environmentally benign conditions, a variety of desirable products were obtained in high yields with complete selectivities and functional group friendliness. Furthermore, the synthesized catalyst could be recycled by simple filtration without obvious loss of catalytic activity after sixth cycle. Notably, this research exhibited the potential of covalent triazine framework-supported transition metal catalysts for hydrogen autotransfer process.
- Liu, Peng,Yang, Jiazhi,Ai, Yao,Hao, Shushu,Chen, Xiaozhong,Li, Feng
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p. 281 - 290
(2021/03/26)
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- Additive-freeN-methylation of amines with methanol over supported iridium catalyst
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An efficient and versatile zinc oxide-supported iridium (Ir/ZnO) catalyst was developed to catalyze the additive-freeN-methylation of amines with methanol. Mechanistic studies suggested that the high catalytic reactivity is rooted in the small sizes (1.4 nm) of Ir nanoparticles and the high ratio (93%) of oxidized iridium species (IrOx, Ir3+and Ir4+) on the catalyst. Moreover, the delicate cooperation between the IrOxand ZnO support also promoted its high reactivity. The selectivity of this catalyticN-methylation was controllable between dimethylation and monomethylation by carefully tuning the catalyst loading and reaction solvent. Specifically, neat methanol with high catalyst loading (2 mol% Ir) favored the formation ofN,N-dimethylated amine, while the mesitylene/methanol mixture with low catalyst loading (0.5 mol% Ir) was prone to producing mono-N-methylated amines. An environmentally benign continuous flow system with a recycled mode was also developed for the efficient production ofN-methylated amines. With optimal flow rates and amine concentrations, a variety ofN-methylamines were produced with good to excellent yields in this Ir/ZnO-based flow system, providing a starting point for the clean and efficient production ofN-methylamines with this cost-effective chemical process.
- Liu, Xiang,Loh, Teck-Peng,Qiang, Wenwen,Wang, Jing,Ye, Sen,Zhu, Longfei
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p. 3364 - 3375
(2021/06/06)
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- Electrochemical C?H Amidation of Heteroarenes with N-Alkyl Sulfonamides in Aqueous Medium
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The construction of C?N bonds by free radical reactions represents a powerful synthetic approach for direct C?H amidations of arenes or heteroarenes. Developing efficient and more environmentally friendly synthetic methods for C?H amidation reactions remains highly desirable. Herein, metal-free electrochemical oxidative dehydrogenative C?H amidations of heteroarenes with N-alkylsulfonamides have been accomplished. The catalyst- and chemical-oxidant-free C?H amidation features an ample scope and employs electricity as the green and sole oxidant. A variety of heteroarenes, including indoles, pyrroles, benzofuran and benzothiophene, thereby underwent this C(sp2)?H nitrogenation. Cyclic voltammetry studies and control experiments provided evidence for nitrogen-centered radicals being directly generated under metal-free electrocatalysis.
- Zhang, Yan,Lin, Zhipeng,Ackermann, Lutz
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supporting information
p. 242 - 246
(2020/11/30)
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- Direct Introduction of Sulfonamide Groups into Quinoxalin-2(1H)-ones by Cu-Catalyzed C3-H Functionalization
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Direct sulfonamidation of quinoxalin-2(1H)-one derivatives has been developed using a readily available Cu salt as the catalyst and inexpensive ammonium persulfate as the oxidant in moderate conditions. Owing to the feature of handy operation and good functional group tolerance, this method provides a convenient and efficient access to curative 3-sulfonamidated quinoxalin-2(1H)-one scaffolds.
- Tan, Yushi,Liu, Boyan,Han, Ya-Ping,Zhang, Yuecheng,Zhang, Hong-Yu,Zhao, Jiquan
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supporting information
p. 3365 - 3369
(2020/10/02)
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- Method for synthesizing N-methyl sulfonamide in water
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The invention discloses a method N - for synthesizing,methylsulfamide in water, by using a transition metal iridium catalyst to catalyze N - methylation reaction. by using a non-toxic and harmless water as a solvent, to avoid using the organic agent; to react only as a byproduct, without an environmental hazard; reaction temperature with respect to the previous strip more mild; and have a wide application prospect; with high selectivity, reaction atomic economy.
- -
-
Paragraph 0050-0054
(2020/03/12)
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- N-Methylation of Amines with Methanol in Aqueous Solution Catalyzed by a Water-Soluble Metal-Ligand Bifunctional Dinuclear Iridium Catalyst
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The N-methylation of amines with methanol in aqueous solution was proposed and accomplished by using a water-soluble metal-ligand bifunctional dinuclear iridium catalyst. In the presence of [(Cp*IrCl)2(thbpym)][Cl]2 (1 mol %), a range of desirable products were obtained in high yields under environmentally benign conditions. Notably, this research exhibited the potential of transition metal-catalyzed activation of methanol as a C1 source for the construction of the C-N bond in aqueous solution.
- Han, Xingyou,Li, Feng,Liu, Peng,Meng, Chong,Tung, Nguyen Thanh
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p. 5815 - 5824
(2020/05/26)
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- Transition-Metal-Free One-Step Synthesis of Ynamides
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A robust transition-metal-free one-step strategy for the synthesis of ynamides from sulfonamides and (Z)-1,2-dichloroalkenes or alkynyl chlorides is presented. This method is not only effective for internal ynamides but also amenable for terminal ynamides. Various functional groups, even the vinyl moiety, are compatible, and thus, this strategy offers the opportunity for further functionalization.
- Zeng, Xianzhu,Tu, Yongliang,Zhang, Zhenming,You, Changming,Wu, Jiao,Ye, Zhiying,Zhao, Junfeng
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p. 4458 - 4466
(2019/03/26)
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- Copper(i)-catalyzed N-H olefination of sulfonamides for: N -sulfonyl enaminone synthesis
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This communication reports copper-catalyzed N-H olefination of sulfonamides for enaminone synthesis using saturated ketones as olefin sources. With TEMPO derivatives and O2 as oxidants, this method provided an efficient way to produce various enaminones in good yields. Mechanistic studies helped figure out the stable intermediates and develop novel methodologies for the difunctionalization of saturated ketones.
- Liang, Xiao,Huang, Xin,Xiong, Mingteng,Shen, Kexin,Pan, Yuanjiang
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supporting information
p. 8403 - 8406
(2018/08/03)
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- Mono-N-methylation of anilines with methanol catalyzed by a manganese pincer-complex
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The selective mono-N-methylation of anilines derivatives was achieved under mild conditions using inexpensive methanol as C1 source. Under hydrogen borrowing conditions, using a tridentate PN3P manganese pre-catalyst (5?mol%), a catalytic amount of base (20?mol%), for 24?h at 120?°C, a large variety of anilines derivatives was methylated in good to excellent yield. Mechanistic investigations allowed us to isolate and characterize by X-ray diffraction studies a de-aromatized manganese intermediate.
- Bruneau-Voisine, Antoine,Wang, Ding,Dorcet, Vincent,Roisnel, Thierry,Darcel, Christophe,Sortais, Jean-Baptiste
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- Copper-Catalyzed Arylsulfonylation and Cyclizative Carbonation of N-(Arylsulfonyl)acrylamides Involving Desulfonative Arrangement toward Sulfonated Oxindoles
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Sulfonated oxindoles are accessed by a Cu(OAc)2-catalyzed three-component reaction of N-(arylsulfonyl)acrylamides, DABSO, and aryldiazonium tetrafluoroborates. This transformation is triggered by the formation of arylsulfonyl radicals in situ from the reaction of aryldiazonium tetrafluoroborates and DABSO. Afterward, the sequential radical addition, radical cyclization, and desulfonylative 1,4-aryl migration take place to provide the final product by the formation of four new bonds in one pot. This procedure shows good functional group tolerance.
- Wang, Hepan,Sun, Song,Cheng, Jiang
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supporting information
p. 5844 - 5847
(2017/11/10)
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- Palladium-Catalyzed Regio- and Chemoselective Reactions of 2-Bromobenzyl Bromides: Expanding the Scope for the Synthesis of Biaryls Fused to a Seven-Membered Sultam
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Speedy access to biaryls fused to seven-membered sultams was achieved by starting from readily accessible N-alkylbenzenesulfonamides and 2-bromobenzyl bromides. The protocol features a domino reaction and proceeds through an N-benzylation followed by an intramolecular direct C-H arylation that occurs ortho to the sulfonamide group. A palladium-catalyzed domino reaction of N-alkylbenzenesulfonamides and 2-bromobenzyl bromides gives biaryls fused to a seven-membered sultam. This approach employs readily accessible substrates and provides speedy access to fused-ring compounds.
- Laha, Joydev K.,Sharma, Shubhra,Dayal, Neetu
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p. 7885 - 7891
(2015/12/24)
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- Establishment of heterolytic and homolytic Y-NO2 bond dissociation energy scales of nitro-containing compounds in acetonitrile: Chemical origin of NO2 release and capture
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(Chemical Equation Presented) The first heterolytic and homolytic N(O)-NO2 bond dissociation energy scales of three types Y-nitro (Y = N, O) compounds and corresponding radical anions in acetonitrile were established by using titration calorimetry combined with relevant electrochemical data through proper thermodynamic cycles.
- Li, Xin,Zhu, Xiao-Qing,Zhang, Fan,Wang, Xiao-Xiao,Cheng, Jin-Pei
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p. 2428 - 2431
(2008/09/20)
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- NOVEL QUINAZOLINES AS 5-HT6 MODULATORS
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The present invention relates to new compounds of formula I, [Chemical formula should be inserted here. Please see paper copy] I or salts, solvates or solvated salts thereof, wherein Q, R1, R2, R3 and n are defined as in c
- -
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Page/Page column 24
(2008/06/13)
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- Nitroso group transfer from N-nitrososulfonamides to thiolate ions. Intrinsic reactivity
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The nitroso group transfer from N-nitrososulfonamides to thiolate ions was studied. Based on the results, the reaction rate is strongly dependent on the nature of the leaving group (αlg ≈ - 1.30), but virtually independent of the basicity of th
- Adam,García-Río,Leis,Moreira
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p. 8822 - 8829
(2007/10/03)
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- Synthesis of phenyl arylsulfonyl-alkyl-dithiocarbamates and their hydrolytic reactivity in hydroxide and hydroperoxide media
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Eight previously unreported phenyl arylsulfonyl-alkyl-dithiocarbamates were synthesized by treatment of arylsulfonamides with phenyl chlorodithioformate in an adaptation of a general amine acylation method. A kinetic investigation of their alkaline hydrolysis was performed and the experimental data are discussed. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Norberto, Fatima,Araujo, M. Eduarda M.,Santos, Lidia,Jaime, Marta S. P.,Mateus, Pedro M. V.,Herves, Pablo
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p. 4710 - 4714
(2007/10/03)
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- In vivo imaging
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A positron emission tomography (PET)-ready library of candidate pharmaceutical agents is provided which can be prepared by a multistep process wherein the final or penultimate step is a reaction using a PET-ready reagent or a plurality of PET-ready reagents. Methods of preparing and using the libraries are also provided.
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- Hydrolysis of aryl N-methyl-N-arylsulfonylcarbamates
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Tertiary sulfonylcarbamates 1 were prepared by reaction of a sulfonamide anion with aryl chloroformates. These previously unreported compounds hydrolyse in aqueous media to the parent sulfonamide and phenol. The pH-rate profile shows both spontaneous and base-catalysed processes. The reaction is also catalysed by buffers. Kinetic data for the hydrolysis of these compounds by HO- are best interpreted in terms of a mechanism involving rate-limiting formation of a tetrahedral intermediate from nucleophilic attack of hydroxide ion at the carbamate carbonyl carbon atom. For the 4-nitrophenylsulfonyl compound 1h decomposition of the tetrahedral intermediate appears to be rate-limiting with the sulfonamide anion, rather than the phenoxide, functioning as the leaving group. The buffer-catalysed process is consistent with general base-catalysed attack of water at the carbamate carbonyl carbon atom.
- Araujo,Campelo,Iley,Norberto
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p. 494 - 497
(2007/10/03)
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- The reversed Kenner linker: A new safety-catch linker for the preparation of N-alkyl sulfonamides
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matrix presented A new strategy for the solid-phase synthesis of sulfonamides is described. The Kenner safety-catch strategy has been modified such that the carboxylic acid component remains attached to the solid support while the sulfonamide portion is released into solution. An initial demonstration of the scope of this strategy is presented, along with an analysis of the cleavage characteristics and extension to more elaborate products via Suzuki reaction and thiazolidinone synthesis.
- Maclean, Derek,Hale, Ron,Chen, Mingying
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p. 2977 - 2980
(2007/10/03)
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- Nitroso group transfer from substituted N-methyl-N-nitrosobenzenesulfonamides to amines. Intrinsic and apparent reactivity
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We have studied the nitroso group transfer from substituted N-methyl-N-nitrosobenzenesulfonamides to primary and secondary amines, observing that the rate of the reaction increases as a consequence of the presence of electron withdrawing groups on the aromatic ring of the nitrosating agents. The rate constants determined for the nitroso group transfer ktr, give good Bronsted-type relationships between log ktr (rate constant for nitroso group transfer) and pKa/R2NH2+ and pKa/leaving group. The study of the nitrosation processes of secondary amines catalyzed by ONSCN and denitrosation catalyzed by SCN-, in combination with the formation equilibrium of ONSCN, has enabled us to calculate the value of the equilibrium constant for the loss of the NO+ group from a protonated N-nitrosamine (pKNO/R2N+ HNO), which can be defined by analogy with pKa/R2NH2+. The value of pKNO/X-NO for the loss of the NO+ group from an N-methyl-N-nitrosobenzenesulfonamide was obtained in a similar way. By using values of ΔpKNO = pKNO/R2N+ HNO - pKNO/X-NO, we were able to calculate the equilibrium constant for the nitroso group transfer and characterize the transition state. On the basis of Bronsted-type correlations, we have obtained values of βnucl/norm and αlg/norm ? 0.55, showing a perfectly balanced transition state. In terms, of the Marcus theory, the calculation of the intrinsic barriers for the nitroso group transfer reaction shows that the presence of electron withdrawing groups on thearomatic ring of the N-methyl-N-nitrosobenzenesulfonamides does not cause these barriers to vary.
- Garcia-Rio,Leis,Moreira,Norberto
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p. 381 - 390
(2007/10/03)
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- S-aminosulfeniminopenicillins: Multimode β-lactamase inhibitors and template structures for penicillin-based β-lactamase substrates as prodrugs
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A series of novel penicillins, bearing an S-aminosulfenimine (R'(R'')NSN=) side chain at the 6-position, have been prepared by direct reaction of a penicillin ester with sulfur diimides. A set of these structures, with the thiazolidine-ring sulfur in the sulfide oxidation state, exhibited a pattern of reactivity not previously encountered in penicillin chemistry, viz., cleavage of the β-lactam ring resulted in a rapid intramolecular displacement of the S-amino moiety as R'(R'')NH. This was found to be the exclusive reaction occurring consequent on cleavage of the β-lactam ring. The mechanism of this process was delineated in a detailed study in basic methanol. That a similar reactivity pattern held for a penicillin salt in aqueous solution was also verified. Thus the salt 5bm (R' = CH3, R'' = p-CH3C6H4SO2) behaved as a moderate substrate for β- lactamase type I from Bacillus cereus (k(cat)/K(m) = 6.26 x 105 M-1 min- 1). On enzyme-catalyzed hydrolysis of this compound, displacement of N- methyl-p-toluenesulfonamide (R'(R'')NH) was directly observed (1H NMR) and found to occur faster than displacement of this group from (intact) 5bm in aqueous buffer, by a factor of at least 600. These findings identified the potential of the s-aminosulfeniminopenicillin structure type to be developed as β-lactamase substrates for use as site-specific-release prodrugs. A degree of enzyme inhibition was also observed with this set of thiazolidine- ring-sulfide structures with the most potent inhibitor having the most nucleofugic S-amino moiety p-ClC6H4SO2N(CH3), indicating that displacement of this group, at the enzyme active site, played a role in their mode of inhibition. Structures with the thiazolidine-ring sulfur in the sulfone oxidation state were considerably more potent as inhibitors, with the structure 5a2 being the most active. As this compound bore the least nucleofugic S-amino moiety C2H5OC(O)NH, it indicated that the mode of inhibition of the sulfones was distinct from that of the thiazolidine-ring sulfides; it is probable that the sulfones reacted in a manner similar to that shown by sulbactam viz., rapid scission of the thiazolidine-sulfone ring after cleavage of the β-lactam ring. Synergy of action was observed with 5a2 at high concentration (78 μg/mL) against Escherichia coli when combined 1:1 with penicillin G; no synergy was observed at low concentration (4 μg/mL) when combined with pipericillin, indicating poor permeation characteristics.
- Smyth, Timothy P.,O'Donnell, Michael E.,O'Connor, Michael J.,St Ledger, James O.
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p. 7600 - 7618
(2007/10/03)
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- Stability and nitrosation efficiency of substituted N-methyl-N-nitrosobenzenesulfonamides
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A series of substituted N-methyl-N-nitrosobenzenesulfonamides [2,4,6-(CH3)3, 4-CH3O, 4-CH3 4-Cl and 4-NO2] were synthesized. All of them transfer their nitroso group to N-methylaniline in a quantitative manner, the more reactive being those substituted with electron-withdrawing groups, thus resembling some of the known alkyl nitrites. Studies of their acid denitrosation and base-catalysed hydrolysis demonstrated that the nitrosobenzenesulfonamides are fairly stable in aqueous media between pH 2 and 11. Their relative stability in aqueous media together with their ability to transfer the nitroso group to nucleophiles suggest their use as excellent alternatives to alkyl nitrites in both neutral and basic media.
- Garcia-Rio,Leis,Moreira,Norberto
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p. 756 - 760
(2007/10/03)
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- Nitrosation and denitrosation of substituted N-methylbenzenesulfonamides. Evidence of an imbalanced concerted mechanism
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The kinetics of the nitrosation reaction of several substituted sulfonamides and of the denitrosation of the resulting products have been studied. The denitrosation rate is first-order with respect to both the nitroso compound and acid concentration and no effect of added nucleophiles was observed. The denitrosation reaction is general-acid catalysed, with a Bronsted parameter αd, of 0.7, which is independent of the substituents on the aromatic ring. Kinetic solvent isotope effects range from kH3O+d/ kD3O+d = 1.20 ± 0.05 to 2.04 ± 0.06 for denitrosation by L3O+ and from kAHd/kADd = 1.5 ± 0.2 to 2.3 ± 0.3 for denitrosation by dichloroacetic acid, which suggest that a rate-determining proton transfer is involved in this reaction. For nitrosation reaction, the absence of catalysis by nucleophilic anions, the observed general-base catalysis (βNO = 0.3) and the substituent effects suggest a concerted nitrosation-denitrosation process. The Leffler parameters obtained for N ... H bond formation (αnuc = 0.7) as well as for N ... N=O bond breaking (αlg = 0.17) are in favour of an imbalance in the transition state (αimbalance = 0.53) with the development of a positive charge on the nitrogen adjacent to the nitroso group.
- Garcia-Rio, Luis,Leis, J. Ramon,Moreira, Jose A.,Norberto, Fatima
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p. 1613 - 1620
(2007/10/03)
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- Evidence for an Isocyanate Formation in the Alkaline Hydrolysis of N1-Alkyl Derivatives of Chlorpropamide, Inhibitors of Aldehyde Dehydrogenase
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Trapping of a propyl isocyanate intermediate and entropies of activation data are consistent with an elimination-addition mechanism AxhDH + DN (E1cB) for the hydrolysis of 1-alkyl-1--3-n-propylurea, the N1-alkyl derivatives of chlorpropamide, inhibitors of aldehyde dehydrogenase.
- Bergon, M.,Vigroux, A.,Tisnes, P.
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p. 946 - 947
(2007/10/02)
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- Tin for Organic Synthesis, 7. New Regioselective Syntheses of Diaryl Sulfones, Arenesulfonamides, and Arenesulfonic Acid Sodium Salts
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The reaction of (trialkylstannyl)arenes 1 with corresponding reagents containing a chlorosulfonyl group leads, by exclusive ipso substitution, to important diaryl sulfones 2a - i, N-alkylarenesulfonamides 8a - f, and sodium arenesulfonates 13a - c in high yields under mild conditions.The specific leaving ability of the stannyl group allows, moreover, the preparation of arylsulfonyl isomers which are not accessible under the influence of the conventional directing forces of substituents.With N,N-dialkylamidosulfonyl chloride / AlCl3 complexes no destannylation takes place, but the first intramolecular sulfonyltin complex 11 is formed.This result is used to discuss details of the mechanism involved. Key Words: Aromatic substitution, electrophilic / Sulfones, synthesis of / Sulfonamides, synthesis of / Sulfonic acids, sodium salts, synthesis of/ Stannanes, trialkylaryl-, application of
- Neumann, Wilhelm P.,Wicenec, Christian
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p. 763 - 768
(2007/10/02)
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- N-ALKYLATION OF SULFONAMIDES USING ANION EXCHANGE RESIN
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Mono-N-alkylated sulfonamides were synthesized in high yields by reacting the sulfonamides supported on anion exchange resin with alkyl halides.
- Sanghavi, N.M.,Parab, V.L.,Patravale, B. S.,Patel, M. N.
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p. 1499 - 1504
(2007/10/02)
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- EFFECT OF STRUCTURE ON THE KINETICS AND MECHANISM OF THE ACID-CATALYZED DECOMPOSITION OF N-ALKYL-N-NITROBENZENESULFONAMIDES
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The decomposition rate of a series of meta- and para-substituted N-alkyl-N-nitrobenzenesufonamides was determined by a spectrophotometric method in aqueous sulfuric acid.It was shown that the decomposition of the compounds takes place both by denitration and by cleavage of the N-S bond with the formation fo primary aliphatic N-nitrosamines.Electron-withdrawing substituents in the aromatic ring shift the process toward denitration.
- Drozdova, O. A.,Astrat'ev, A. A.,Kuznetsov, L. L.,Selivanov, V. F.
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p. 671 - 675
(2007/10/02)
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