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N-Aroylsulfonamide-Photofragmentation (ASAP)-A Versatile Route to Biaryls
The photochemical fragmentation of N-aroylsulfonamides 9 (ASAP) is a powerful method for the preparation of various biaryls. Compounds 9 are easily accessible in two steps from amines by treatment with arenesulfonyl chlorides and aroyl chlorides. Many of these compounds were prepared for the first time. The irradiation takes place in a previously developed continuous-flow reactor using inexpensive UVB or UVC fluorescent lamps. Isocyanates and sulphur dioxide are formed as the only by-products. The ASAP tolerates a variety of functional groups and is even suited for the preparation of phenylnaphthalenes and terphenyls. The ASAP mechanism was elucidated by interaction of photophysical and quantum chemical (DFT) methods and revealed a spirocyclic biradical as key intermediate.
Wessig, Pablo,Krebs, Saskia
supporting information
p. 6367 - 6374
(2021/09/29)

Structurally Diverse Synthesis of Five-, Six-, and Seven-Membered Benzosultams through Electrochemical Cyclization
We have developed a metal- and oxidant-free approach to structurally diverse synthesis of benzosultams from aryl sulfonamides through an electrochemical cyclization. Upon variation of the ortho substituent on aryl sulfonamides, five-, six-, and seven-memb
Liu, Aiyun,Guo, Tiantian,Zhang, Shuangshuang,Yang, Han,Zhang, Qi,Chai, Yonghai,Zhang, Shengyong
supporting information
p. 6326 - 6331
(2021/08/23)

Electrochemical C?H Amidation of Heteroarenes with N-Alkyl Sulfonamides in Aqueous Medium
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
supporting information
p. 242 - 246
(2020/11/30)

Boronic Acid Pairs for Sequential Bioconjugation
Boronic acids can play diverse roles when applied in biological environments, and employing boronic acid structures in tandem could provide new tools for multifunctional probes. This Letter describes a pair of boronic acid functional groups, 2-nitro-arylboronic acid (NAB) and (E)-alkenylboronic acid (EAB), that enable sequential cross-coupling through stepwise nickel- and copper-catalyzed processes. The selective coupling of NAB groups enables the preparation of stapled peptides, protein-protein conjugates, and other bioconjugates.
Ball, Zachary T.,Ding, Yuxuan,Miller, Mary K.,Swierczynski, Michael J.
supporting information
p. 5334 - 5338
(2021/07/26)

Copper-catalyzed oxidative methylation of sulfonamides by dicumyl peroxide
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
p. 935 - 942
(2021/01/05)

Recyclable covalent triazine framework-supported iridium catalyst for the N-methylation of amines with methanol in the presence of carbonate
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
p. 281 - 290
(2021/03/26)

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)]
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
p. 2621 - 2631
(2021/02/27)

Efficient and Practical Synthesis of Sulfonamides Utilizing SO2 Gas Generated on Demand
A simple and practical protocol was developed for the synthesis of sulfonamides by reacting organometallic reagents with SO2 gas generated on demand. SO2 was generated from readily available reagents safely in a highly contained and controlled fashion. The protocol allows the synthesis of sulfonamides without using either atom-inefficient SO2 surrogates or a SO2 cylinder that requires stringent storage regulations in the laboratory. The protocol was successfully applied to the synthesis of sildenafil.
Chung Leung, Gulice Yiu,Ramalingam, Balamurugan,Loh, Gabriel,Chen, Anqi
p. 546 - 554
(2020/04/22)

Direct Introduction of Sulfonamide Groups into Quinoxalin-2(1H)-ones by Cu-Catalyzed C3-H Functionalization
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
supporting information
p. 3365 - 3369
(2020/10/02)

Method for synthesizing N-methyl sulfonamide in water
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.
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Paragraph 0025-0029; 0115; 0116

(2020/03/12)

N-Methylation of Amines with Methanol in Aqueous Solution Catalyzed by a Water-Soluble Metal-Ligand Bifunctional Dinuclear Iridium Catalyst
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
p. 5815 - 5824
(2020/05/26)

Sulfonamide Synthesis through Electrochemical Oxidative Coupling of Amines and Thiols
Sulfonamides are key motifs in pharmaceuticals and agrochemicals, spurring the continuous development of novel and efficient synthetic methods to access these functional groups. Herein, we report an environmentally benign electrochemical method which enables the oxidative coupling between thiols and amines, two readily available and inexpensive commodity chemicals. The transformation is completely driven by electricity, does not require any sacrificial reagent or additional catalysts and can be carried out in only 5 min. Hydrogen is formed as a benign byproduct at the counter electrode. Owing to the mild reaction conditions, the reaction displays a broad substrate scope and functional group compatibility.
Laudadio, Gabriele,Barmpoutsis, Efstathios,Schotten, Christiane,Struik, Lisa,Govaerts, Sebastian,Browne, Duncan L.,No?l, Timothy
supporting information

(2019/04/16)

Sulfonamide Synthesis through Electrochemical Oxidative Coupling of Amines and Thiols
Sulfonamides are key motifs in pharmaceuticals and agrochemicals, spurring the continuous development of novel and efficient synthetic methods to access these functional groups. Herein, we report an environmentally benign electrochemical method which enables the oxidative coupling between thiols and amines, two readily available and inexpensive commodity chemicals. The transformation is completely driven by electricity, does not require any sacrificial reagent or additional catalysts and can be carried out in only 5 min. Hydrogen is formed as a benign byproduct at the counter electrode. Owing to the mild reaction conditions, the reaction displays a broad substrate scope and functional group compatibility.
Laudadio, Gabriele,Barmpoutsis, Efstathios,Schotten, Christiane,Struik, Lisa,Govaerts, Sebastian,Browne, Duncan L.,No?l, Timothy
supporting information
p. 5664 - 5668
(2019/04/17)

Copper(i)-catalyzed N-H olefination of sulfonamides for: N -sulfonyl enaminone synthesis
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
supporting information
p. 8403 - 8406
(2018/08/03)

Selective cleavage of the N-propargyl group from sulfonamides and amides under ruthenium catalysis
The selective cleavage of the N-propargyl group from sulfonamides and amides under ruthenium catalysis is described. The reaction tolerates a broad range of functional groups, and the desired products were obtained in 10–95% yield.
Wang, Jingjing,Li, Feng,Pei, Wenlong,Yang, Mixue,Wu, Yidan,Ma, Danyang,Zhang, Furong,Wang, Jianhui
supporting information
p. 1902 - 1905
(2018/04/19)

Methylation of Amines and Ketones with Methanol Catalyzed by an Iridium Complex Bearing a 2-Hydroxypyridylmethylene Fragment
Reaction of complex [Cp?Ir(HOC5H3CH2C5H3OH)Cl][Cl] (1) with AgOTf generated the product [Cp?Ir(HOC5H3CH2C5H3OH)(H2O)][OTf]2 (2), which was further transformed to the complex [Cp?Ir(OC5H3CH2C5H3O)(H2O)] (3) in the presence of t-BuONa via -OH deprotonation. Complexes 1-3 exhibited high activity for the methylation of amines and ketones. These C-C and C-N coupling reactions proceeded in air with 1 mol % catalyst loading in the presence of K2CO3.
Deng, Danfeng,Hu, Bowen,Yang, Min,Chen, Dafa
p. 3353 - 3359
(2018/09/25)

Iron-Catalyzed Methylation Using the Borrowing Hydrogen Approach
A general iron-catalyzed methylation has been developed using methanol as a C1 building block. This borrowing hydrogen approach employs a Kn?lker-type (cyclopentadienone)iron carbonyl complex as catalyst (2 mol %) and exhibits a broad reaction scope. A variety of ketones, indoles, oxindoles, amines, and sulfonamides undergo mono- or dimethylation in excellent isolated yields (>60 examples, 79% average yield).
Polidano, Kurt,Allen, Benjamin D. W.,Williams, Jonathan M. J.,Morrill, Louis C.
p. 6440 - 6445
(2018/07/25)

Copper-Catalyzed Arylsulfonylation and Cyclizative Carbonation of N-(Arylsulfonyl)acrylamides Involving Desulfonative Arrangement toward Sulfonated Oxindoles
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
supporting information
p. 5844 - 5847
(2017/11/10)

N-Methylation of Amines with Methanol Catalyzed by a Cp?Ir Complex Bearing a Functional 2,2′-Bibenzimidazole Ligand
A new type of Cp?Ir complex bearing a functional 2,2′-bibenzimidazole ligand was designed, synthesized, and found to be a highly effective and general catalyst for the N-methylation of a variety of amines with methanol in the presence of a weak base (0.3 equiv of Cs2CO3).
Liang, Ran,Li, Shun,Wang, Rongzhou,Lu, Lei,Li, Feng
supporting information
p. 5790 - 5793
(2017/11/10)

Mono-N-methylation of anilines with methanol catalyzed by a manganese pincer-complex
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
p. 57 - 62
(2017/02/13)

UV Light Induced Direct Synthesis of Phenanthrene Derivatives from a Linear 3-Aryl-N-(arylsulfonyl) Propiolamides
A novel photochemical approach for the synthesis of phenanthrene derivatives from linear 3-aryl-N-(arylsulfonyl) propiolamides via a tandem radical Smiles rearrangement/C-S bonding/Mallory reaction is disclosed. The control experiment results and isolation of the key intermediates give further insight into the reaction mechanism. Gram scale reaction using a flow reactor demonstrated the synthetic potential applications of our protocol.
Chen, Ming,Yang, Chao,Wang, Yanpei,Li, Dazhi,Xia, Wujiong
supporting information
p. 2280 - 2283
(2016/06/01)

N-Methylation of poorly nucleophilic aromatic amines with dimethyl carbonate
Abstract: Dimethyl carbonate (DMC), an environmentally friendly methylation agent, is a substitute for traditional methylation agents such as methyl halides (CH3X, X?=?I, Br, Cl) or dimethyl sulfate. An efficient, convenient, and green method has been developed for N-methylation of poorly nucleophilic aromatic amines with DMC. It was found that the couple PEG400/K2CO3 provides good selectivity for the N-methylation product. Finally, the mechanism for reaction of amines with DMC was investigated, and a plausible multistep mechanism proposed and verified. Graphical Abstract: [Figure not available: see fulltext.]
Yan, Huidong,Zeng, Liufang,Xie, Yaqiang,Cui, Yu,Ye, Liyi,Tu, Song
p. 5951 - 5960
(2016/06/01)

Visible Light-Induced Radical Rearrangement to Construct C-C Bonds via an Intramolecular Aryl Migration/Desulfonylation Process
A highly efficient intramolecular selective aryl migration/desulfonylation of 2-bromo-N-aryl-N-(arenesulfonyl)amide via visible light-induced photoredox catalysis has been accomplished. This approach allows for the construction of a variety of multisubstituted N,2-diarylacetamide under mild reaction conditions.
Li, Yuyuan,Hu, Bei,Dong, Wuheng,Xie, Xiaomin,Wan, Jun,Zhang, Zhaoguo
p. 7036 - 7041
(2016/08/30)

Halofluorination of N-protected α,β-dehydro-α-amino acid esters—A convenient synthesis of α-fluoro-α-amino acid derivatives
N-protected dehydroamino acid methyl esters have been converted to α-fluoro-β-halo amino acid derivatives under halofluorination reaction conditions. The influences of the nitrogen protecting group of the substrates and of the halonium electrophile on the reaction outcome and the stability of the obtained products have been studied. Furthermore, reduction of the halogen substituent (Cl or Br) under radical conditions provided a possibility for follow-up reactions. Nucleophilic substitution reactions, however, failed.
Ulbrich, Dirk,Daniliuc, Constantin G.,Haufe, Günter
p. 65 - 75
(2016/07/11)

Palladium-Catalyzed Regio- and Chemoselective Reactions of 2-Bromobenzyl Bromides: Expanding the Scope for the Synthesis of Biaryls Fused to a Seven-Membered Sultam
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
p. 7885 - 7891
(2015/12/24)

Efficient ruthenium-catalyzed N-methylation of amines using methanol
An in situ-generated complex from [RuCpCl2]2 and dpePhos ligand is reported as an efficient catalyst in the presence of 5 mol % of LiOtBu for the N-methylation of amines using methanol as the methylating agent at moderate conditions, following hydrogen borrowing strategy. This simple catalyst system provides selective N-monomethylation of substituted primary anilines and sulfonamides as well as N,N dimethylation of primary aliphatic amines in excellent yields at 40-100 °C with good tolerance to reducible functional groups. The catalytic intermediate CpRu(dpePhos)H was isolated and was shown to be active for methylation in the absence of base.
Dang, Tuan Thanh,Ramalingam, Balamurugan,Seayad, Abdul Majeed
p. 4082 - 4088
(2015/11/11)

Oxidative debenzylation of N-benzyl amides and O-benzyl ethers using alkali metal bromide
The oxidative debenzylation of N-benzyl amides and O-benzyl ethers was promoted with high efficiency by a bromo radical formed through the oxidation of bromide from alkali metal bromide under mild conditions. This reaction provided the corresponding amides from N-benzyl amides and carbonyl compounds from O-benzyl ethers in high yields.
Moriyama, Katsuhiko,Nakamura, Yu,Togo, Hideo
p. 3812 - 3815
(2014/08/05)

Nickel-Catalyzed Desulfitative Suzuki-Miyaura Cross-Coupling of N,N-Disulfonylmethylamines and Arylboronic Acids
A nickel-catalyzed approach for the synthesis of biaryl compounds from N,N-disulfonylmethylamines and arylboronic acids has been developed. Instead of arenesulfonyl chlorides, various N,N-disulfonylmethylamines were used as the aryl source through extrusion of SO2 to give cross-coupling products in moderate to good yields. A NiCl2(dppp)-catalyzed [dppp = 1,3-bis(diphenylphosphino)propane] desulfitative Suzuki-Miyaura cross-coupling reaction between N,N-disulfonylmethylamines and arylboronic acids is described for the first time. The biaryl compounds are obtained in moderate to good yields.
Chen, Liangshun,Lang, Hongyue,Fang, Lei,Yu, Jianjun,Wang, Limin
supporting information
p. 6385 - 6389
(2016/02/18)

General and efficient method for direct N-monomethylation of aromatic primary amines with methanol
The direct N-monomethylation of aromatic primary amines, including arylamines, arylsulfonamides and amino-azoles, using methanol as a methylating agent has been accomplished in the presence of a [CpIrCl2]2/NaOH system. From both synthetic and environmental points of view, the reaction is highly attractive because of low catalyst loading, broad substrate scope and excellent selectivities.
Li, Feng,Xie, Jianjiang,Shan, Haixia,Sun, Chunlou,Chen, Lin
p. 8645 - 8652
(2015/03/05)

Establishment of heterolytic and homolytic Y-NO2 bond dissociation energy scales of nitro-containing compounds in acetonitrile: Chemical origin of NO2 release and capture
(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
p. 2428 - 2431
(2008/09/20)

NOVEL QUINAZOLINES AS 5-HT6 MODULATORS II
The present invention relates to new compounds of formula I, or salts, solvates or solvated salts thereof, wherein Q, B, R1, R2, R3, R4, m and n are defined as in claim 1, processes for their preparation and to
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Page/Page column 41

(2010/11/28)

Synthesis of phenyl arylsulfonyl-alkyl-dithiocarbamates and their hydrolytic reactivity in hydroxide and hydroperoxide media
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
p. 4710 - 4714
(2007/10/03)

Novel N-dealkylation of N-alkyl sulfonamides and N,N-dialkyl sulfonamides with periodic acid catalyzed by chromium(III) acetate hydroxide
Chromium(III) acetate hydroxide has been found to be an efficient catalyst for N-dealkylation of N-alkyl sulfonamides and N,N-dialkyl sulfonamides to furnish sulfonamides in good to excellent yields with periodic acid in acetonitrile at room temperature.
Xu, Liang,Zhang, Suhong,Trudell, Mark L.
p. 1901 - 1904
(2007/10/03)

In vivo imaging
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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(2008/06/13)

Hydrolysis of aryl N-methyl-N-arylsulfonylcarbamates
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
p. 494 - 497
(2007/10/03)

The reversed Kenner linker: A new safety-catch linker for the preparation of N-alkyl sulfonamides
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
p. 2977 - 2980
(2007/10/03)

Kinetics and mechanism of hydrolysis of N-amidomethylsulfonamides
The kinetics of the hydrolyses of secondary and tertiary N-amidomethylsulfonamides were studied at 50 °C. Both types of N-amidomethylsulfonamide hydrolyse through acid- and base-catalysed processes, as indicated by the pH-rate profiles. The order of reactivity for the acid-catalysed pathway implies a mechanism involving protonation of the amide followed by expulsion of a neutral amide and formation of a sulfonyliminium ion. In the base-catalysed region, compound 5c, which is substituted at both amide and sulfonamide nitrogen atoms, hydrolyses by nucleophilic attack of hydroxide ion at the amide carbonyl carbon atom to form benzoic acid and a sulfonamide. In contrast, compound 5b, which contains a sulfonamide NH group, hydrolyses to benzamide and sulfonamide products by an E1cbrev mechanism involving ionisation of the sulfonamide. Compound 5a, which contains an amide NH, also hydrolyses to sulfonamide and amide products, probably by an E2 mechanism.
Iley, Jim,Lopes, Francisca,Moreira, Rui
p. 749 - 753
(2007/10/03)

Nucleophilic reactivity towards electrophilic fluorinating agents: Reaction with N-fluorobenzenesulfonimide ((PhSO2)2NF)
Second-order rate constants for the reaction of N-fluorobenzenesulfonimide (FBS) with nucleophilic reagents, kNu (M-1 s-1), have been measured in aqueous solution at 25°C. Analysis of the reaction products shows that soft polarizable nucleophiles (I-, SCN-, Br-) react at fluorine, whereas hard nucleophiles (oxygen and nitrogen nucleophiles) react at sulfur. The ambident behaviour of this electrophile seems to be related to the relative contribution of electrostatic and orbital interactions in reaching the transition state. The preferential reaction of soft nucleophiles at fluorine and the correlation of kNu values with the one-electron oxidation potentials of the nucleophiles in water suggest that nucleophilic reactivity at fluorine is largely determined by the ease of one-electron transfer from the nucleophile to the electrophile. Nucleophilic addition to fluorine is far more sensitive to the nature of the attacking nucleophile than the corresponding reactions at both saturated (n scale) and unsaturated carbon (N+ scale). Comparison of the rate constants for the reaction of nucleophiles at the sulfonyl group with those for reaction of the same nucleophiles with 2,4-dinitrophenyl acetate reveals a similar reactivity pattern for sulfonyl sulfur and carbonyl carbon as electrophilic centres.
Antelo, Juan M.,Crugeiras, Juan,Leis, J. Ramon,Rios, Ana
p. 2071 - 2076
(2007/10/03)

Experimental and Computational Evidence for the Formation of Iminopersulfinic Acids
An experimental and computational study of the reactions of singlet oxygen with N-substituted sulfenamides is reported. Intermediates capable of epoxidizing norbornene were observed during the photooxidations of three sulfenamides. These results are used to argue for formation of iminopersulfinic acids. The structural integrity of two iminopersulfinic acids was supported by their successful location at the MP2/6-31G* level of theory. Furthermore, the inability to locate computationally significant persulfinimide precursors suggests that the iminopersulfinic acids form by enelike reactions involving near-simultaneous addition of singlet oxygen to sulfur and hydrogen abstraction.
Clennan, Edward L.,Chen, Ming-Fang,Greer, Alexander,Jensen, Frank
p. 3397 - 3402
(2007/10/03)

A general acid-catalyzed anion breakdown associated with an E1cB reaction in the hydrolysis of aryl N-(substituted phenylsulfonyl)carbamates
The hydrolysis of aryl N-(substituted phenylsulfonyl)carbamates at 50 °C in the pH range 0-13.5 leading to substituted benzenesulfonamides and phenols involves acyl group transfer. Reaction rates were measured spectrophotometrically and are independent of
Vigroux, Alain,Bergon, Michel,Bergonzi, Catherine,Tisnès, Pierre
p. 11787 - 11796
(2007/10/02)

Synthesis of Spiro(oxazolidinediones): Spiro-2',3(2H),4'-triones and Spiro-2',4'-dione 1,1-Dioxides
Members of two novel families of spiro(oxazolidinediones) have been prepared.Spiro-2',3(2H),4'-triones (4) were synthesized from the corresponding 1-hydroxy-1-carboethoxyethylisoindol-3-one (7) or (10) or their primary amide
Wrobel, Jay,Dietrich, Arlene
p. 1823 - 1838
(2007/10/02)

Certain N-(R-sulfonyl) phosphonamidothioates and dithioates
Compounds of the formula STR1 wherein the symbols have assigned meanings, and their use as insecticides and/or miticides.
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(2008/06/13)

Multinuclear NMR Study of Variously Substituted Sulphonamides and Sulphinamides
13C, 15N and 17O NMR chemical shifts, and also 1J(CH) and 1J(NH) values, have been determined for variously substituted sulphonamides and some sulphinamides, either neat or in acetone or dimethyl sulphoxide solution.The effect of benzene ring substitutens on the chemical shifts of nitrogen and oxygen nuclei is slight, but N-substitution changes the shielding of both nuclei.Generally, an N-methyl substituent shields an amide nitrogen and an N,Ndimethyl substituent gives further slight shielding.On the other hand, an N-phenyl substituent deshilds the nitrogen strongly, but the deshielding effect of an N,N-diphenyl substituent is markedly smaller.The sulphonyl oxygens are deshilded relative to the sulphinyl oxygens, and N-methyl and N,N-dimethyl substituents shild the oxygen nucleus.The effect of N-phenyl and N,N-diphenyl substituents on the shielding of the oxygen atoms of the sulphonyl group is slight.The direct 1J(CH) coupling constants are similar, but they are characteristic of different type of sulphur amides.The 1J(NH) values are of the same order of magnitude for sulphonamides and sulphinamides, but are clearly smaller for N-unsubstituted amides than for N-substituted compounds.KEY WORDS Sulphonamide Sulphinamide Multinuclear NMR
Ruosteuso, P.,Haekkinen, A.-M.,Mattila, T.
p. 189 - 193
(2007/10/02)

The Reaction of N-Alkylhydroxamic Acids with Sulphinyl Chlorides
The reaction of several N-methylhydroxamic acids with methane- and benzene-sulphinyl chloride is shown to give an isolatable O-sulphinylated intermediate (IV) below 0 deg C.The intermediates decompose at ambient temperatures with simultaneous N-O and S-O bond fission to give the isomeric N-acyl-N-methylsulphonamide (V) and N-methyl-O-sulphonylhydroxamic acid (VI) by in-cage and free pair radical recombination. 1H and 13C n.m.r. spectra show strong polarisations in both sulphonamide (V) and O-sulphonylhydroxamic acid (VI), indicating radical cage mechanisms.In addition, a strong e.s.r. signal was observed due to the N-acyl- N-methylnitroxyl radical (X).
Banks, Malcolm R.,Hudson, Robert F.
p. 1211 - 1216
(2007/10/02)

Pseudomolecular Rearrangement of O-Ethyl N-Methyl Toluene-4-sulphonimidate to N-Ethyl-N-methyltoluene-4-sulphonamide and its Relevance to the Nucleophilic Properties of Neutral Sulphonamides
Kinetic studies are reported for the pseudo-molecular rearrangement of O-ethyl N-methyl toluene-4-sulphonimidate to N-ethyl-N-methyltoluene-4-sulphonamide in organic solvents at 34-100 deg C.Without catalysts, the rearrangement follows the equation rate = krearr 2, which is indicative of an intermolecular SN2 transalkylation via an ion-pair intermediate: it is accompained by concurrent E2 elimination to N-methyltoluene-4-sulphonamide.The rearrangement is catalysed by electrophilic reagents such as alkyl halides, ZnI2, and HBr where rate = k2 .For alkyl halides, a two-step mechanism via an ionic intermediate applies in which formation of the intermediate by an SN2 reaction between the substrate and alkyl halide is rate limiting.Other catalysts effect rearrangement by forming alkyl halides in an initial rapid reaction with the substrate.The results are discussed in relation to the ambident nucleophilic properties of sulphonamides.It is suggested that, like carboxylic acid amides and phosphinylamides, alkylation occurs most readily at the O-atom of neutral sulphonamides to give a sulphonimidate (kinetic product), which then rearranges in the presence of electrophilic catalysts to give an N-substituted sulphonamide (thermodynamic product).Rearrangement is normally too fast for the isolation of O-alkyl sulphonimidates, but O-aryl analogues can be obtained.
Challis, Brian C.,Iley, James N.
p. 699 - 704
(2007/10/02)

EFFECT OF STRUCTURE ON THE KINETICS AND MECHANISM OF THE ACID-CATALYZED DECOMPOSITION OF N-ALKYL-N-NITROBENZENESULFONAMIDES
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.
p. 671 - 675
(2007/10/02)

Unusual Solvolysis of N-Benzylarylsulphonamides: N-C Bond Fission in Concentrated Sulphuric Acid
Hydrolysis of N-benzylarylsulphonamides with conc. sulphuric acid results in the formation of abnormal products arising from N-C bond fission.This has been rationalised by invoking the formation of benzyl carbonium ion.
Gawali, B. B.,Neelakantan, Parvathi,Rao, S. Nagabhushan,Iyengar, D. S.,Bhalerao, U. T.
p. 616 - 617
(2007/10/02)