- Ultrasound-assisted one-pot three-component synthesis of new isoxazolines bearing sulfonamides and their evaluation against hematological malignancies
-
In the present study, following a one-pot two-step protocol, we have synthesized novel sulfonamides-isoxazolines hybrids (3a-r) via a highly regioselective 1,3-dipolar cycloaddition. The present methodology capitalized on trichloroisocyanuric acid (TCCA) as a safe and ecological oxidant and chlorinating agent for the in-situ conversion of aldehydes to nitrile oxides in the presence of hydroxylamine hydrochloride, under ultrasound activation. These nitrile oxides could be engaged in 1,3-dipolar cycloaddition reactions with various alkene to afford the targeted sulfonamides-isoxazolines hybrids (3a-r). The latter were assessed for their antineoplastic activity against model leukemia cell lines (Chronic Myeloid Leukemia, K562 and Promyelocytic Leukemia, HL-60).
- Talha, Aicha,Favreau, Cécile,Bourgoin, Maxence,Robert, Guillaume,Auberger, Patrick,EL Ammari, Lahcen,Saadi, Mohamed,Benhida, Rachid,Martin, Anthony R.,Bougrin, Khalid
-
-
- Metal-free synthesis of biaryls from aryl sulfoxides and sulfonanilides via sigmatropic rearrangement
-
Treatment of aryl sulfoxides and sulfonanilides with trifluoroacetic anhydride resulted in the dehydrative metal-free construction of the corresponding unsymmetrical biaryls. The reaction would proceed via (1) the activation of aryl sulfoxide with the anhydride, (2) interrupted Pummerer reaction of the resulting arylsulfonium with sulfonanilide, (3) [3,3] sigmatropic rearrangement to cleave the transient S–N bond and to form the prospective biaryl C–C bond, and (4) global aromatization. The choice of the amino protecting group is crucial, and only N-sulfonylanilines, i.e., sulfonanilides, could participate in the formation of biaryls.
- Yoshida, Akira,Okamoto, Koichi,Yanagi, Tomoyuki,Nogi, Keisuke,Yorimitsu, Hideki
-
-
- Copper-catalyzed redox coupling of nitroarenes with sodium sulfinates
-
A simple copper-catalyzed redox coupling of sodium sulfinates and nitroarenes is described. In this process, abundant and stable nitroarenes serve as both the nitrogen sources and oxidants, and sodium sulfinates act as both reactants and reductants. A variety of aromatic sulfonamides were obtained in moderate to good yields with broad substrate scope. No external additive is employed for this kind of transformation.
- Liu, Saiwen,Chen, Ru,Zhang, Jin
-
-
- Ligand-Enabled Gold-Catalyzed C(sp2)-N Cross-Coupling Reactions of Aryl Iodides with Amines
-
The first example of ancillary (P,N)-ligand-enabled gold-catalyzed C-N cross-coupling reactions of aryl iodides with amines is reported. The high generality of the reaction in de novo synthesis, late-stage modifications, and cascade processes to access functionalized indolinones and carbazoles underscores the synthetic potential of the presented strategy. Monitoring the reaction with ESI-HRMS and NMR provided strong evidence for the in situ formation of putative high valent Au(III) intermediates.
- Akram, Manjur O.,Das, Avishek,Chakrabarty, Indradweep,Patil, Nitin T.
-
supporting information
p. 8101 - 8105
(2019/10/11)
-
- Continuous-Flow Electrosynthesis of Benzofused S-Heterocycles by Dehydrogenative C?S Cross-Coupling
-
Reported herein is the synthesis of benzofused six-membered S-heterocycles by intramolecular dehydrogenative C?S coupling using a modular flow electrolysis cell. The continuous-flow electrosynthesis not only ensures efficient product formation, but also obviates the need for transition-metal catalysts, oxidizing reagents, and supporting electrolytes. Reaction scale-up is conveniently achieved through extended electrolysis without changing the reaction conditions and equipment.
- Huang, Chong,Qian, Xiang-Yang,Xu, Hai-Chao
-
supporting information
p. 6650 - 6653
(2019/04/26)
-
- Facile Chan-Lam coupling using ferrocene tethered N-heterocyclic carbene-copper complex anchored on graphene
-
Ferrocene tethered N-heterocyclic carbene-copper complex anchored on graphene ([GrFemImi]NHC@Cu complex) has been synthesized by covalent grafting of ferrocenyl ionic liquid in the matrix of graphene followed by metallation with copper (I) iodide. The [GrFemImi]NHC@Cu complex has been characterized by fourier transform infrared (FT-IR), fourier transform Raman (FT-Raman), CP-MAS 13C NMR spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), energy dispersive X-ray (EDX) analysis, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) surface area analysis and X-ray diffractometer (XRD) analysis. This novel complex served as a robust heterogeneous catalyst for the synthesis of bioactive N-aryl sulfonamides from variety of aryl boronic acids and sulfonyl azides in ethanol by Chan-Lam coupling. Recyclability experiments were executed successfully for six consecutive runs.
- Gajare, Shivanand,Jagadale, Megha,Naikwade, Altafhusen,Bansode, Prakash,Rashinkar, Gajanan
-
-
- Soft-Hard Acid/Base-Controlled, Oxidative, N-Selective Arylation of Sulfonanilides via a Nitrenium Ion
-
In iodine(III)-catalyzed, dehydrogenative arylations of sulfonanilides, the functionalization of C-C bonds is preferred over the functionalization of C-N bonds. Herein, an unprecedented N-selective arylation of sulfonanilides using soft-hard acid-base (SHAB) control by a nitrenium ion over a carbenium ion is reported. Treatment of sulfonanilides with iodine(III) led to the formation of nitrenium ions (soft), which preferentially react with biphenyls (soft) over bimesityl (hard) to generate C-N bonds. The iodine(III) was generated in situ by using PhI and mCPBA at room temperature.
- Maiti, Saikat,Mal, Prasenjit
-
p. 1340 - 1347
(2018/02/09)
-
- Synthesis of CF3CH2-Containing Indolines by Transition-Metal-Free Aryltrifluoromethylation of Unactivated Alkenes
-
With an unactivated double bond as the radical acceptor, allyl amines underwent a metal-free trifluoromethylation/cyclization cascade with CF3SO2Na (Langlois' reagent), affording CF3CH2-containing indolines and tetrahydroisoquinolines, whose practical syntheses are significant challenges. This protocol features mild conditions, low cost, and a broad substrate scope.
- Liang, Deqiang,Dong, Qishan,Xu, Penghui,Dong, Ying,Li, Weili,Ma, Yinhai
-
supporting information
p. 11978 - 11986
(2018/09/27)
-
- Synthetic method of CF3-containing indoline and 1,2,3,4-tetrahydroisoquinoline
-
The invention discloses a synthetic method of CF3-containing indoline and 1,2,3,4-tetrahydroisoquinoline and relates to the technical field of compound synthesis. The synthetic method herein is basedon metal-free trifluoromethylation/cyclization free radical cascade reaction using a nonactive olefin dual-bond as a free radical receptor; the reaction aforementioned helps synthesize, in one step, CF3-containing indoline and 1,2,3,4-tetrahydroisoquinoline. The synthetic method herein has the significant advantages of mild conditions, good operational simplicity, low cost, wide substrate range, good exo selectivity and the like.
- -
-
Paragraph 0027; 0029; 0030; 0031; 0042
(2019/01/14)
-
- Novel substituted sulfamide compound, preparation method and application thereof as PTP1B inhibitor
-
The invention relates to a novel substituted sulfamide compound of a structure of a formula I as shown in the description, a pharmaceutically acceptable salt of the novel substituted sulfamide compound, a preparation method, and relates to a medicinal composition comprising the compound of the formula I or a pharmaceutically acceptable salt of the compound. The compound of the formula I or the pharmaceutically acceptable salt of the compound has activity of inhibiting protein tyrosine phosphatase 1B (PTP1B), so that the compound or the pharmaceutically acceptable salt of the compound has an application of preparing a medicine for preventing/treating symptoms or diseases such as hyperglycemia and type-2 diabetes.
- -
-
Paragraph 0019
(2017/06/28)
-
- 1,3,4-OXADIAZOLE SULFONAMIDE DERIVATIVE COMPOUNDS AS HISTONE DEACETYLASE 6 INHIBITOR, AND THE PHARMACEUTICAL COMPOSITION COMPRISING THE SAME
-
The present invention relates to novel compounds represented by the formula I having histone deacetylase 6 (HDAC6) inhibitory activity, stereoisomers thereof or pharmaceutically acceptable salts thereof, the use thereof for the preparation of therapeutic medicaments, pharmaceutical compositions containing the same, a method for treating diseases using the composition, and methods for preparing the novel compounds. (I) The novel compounds, stereoisomers thereof or pharmaceutically acceptable salts thereof according to the present invention have histone deacetylase (HDAC) inhibitory activity and are effective for the prevention or treatment of HDAC6-mediated diseases.
- -
-
Paragraph 1170; 1171; 1172
(2017/02/24)
-
- Novel sulfonamide compound, preparation method, and use of novel sulfonamide compound as protein tyrosine phosphatase 1B inhibitor
-
The invention relates to a novel sulfonamide compound in a structure of a general formula I as shown in the specification, or pharmaceutically acceptable salt and a preparation method of the novel sulfonamide compound, and further relates to a drug composition containing the compound as shown as the general formula I or the pharmaceutically acceptable salt of the compound, and a use of the compound or the pharmaceutically acceptable salt for preparing a drug for preventing and/or treating symptoms or diseases such as hyperglycemia and diabetes mellitus type 2 since the compound as shown as the general formula I or the pharmaceutically acceptable salt of the compound has activity of inhibiting a protein tyrosine phosphatase 1B (PTP 1B).
- -
-
Paragraph 0018
(2017/12/29)
-
- An Organic Intermolecular Dehydrogenative Annulation Reaction
-
The discovery of a direct method for the synthesis of three-ring heterocyclic carbazoles from unactivated arenes and anilides by a metal-free (organic) intermolecular dehydrogenative annulation reaction under ambient laboratory conditions is reported. Iodine(III) was used as the sole reagent either stoichiometrically from inexpensive phenyliodine diacetate or organocatalytically by in situ generation from PhI-mCPBA. In a single step, three C(sp2)-H bonds and one N(sp3)-H bond are functionalized from two different arenes for tandem C-C and C-N bond formation reactions.
- Maiti, Saikat,Achar, Tapas Kumar,Mal, Prasenjit
-
supporting information
p. 2006 - 2009
(2017/04/28)
-
- Carbon-Phosphorus Bond Formation on Anilines Mediated by a Hypervalent Iodine Reagent
-
Substituted anilines containing a sulfonyl group may be oxidized in situ in the presence of methanol and a hypervalent iodine reagent to form an active iminium species. Subsequent addition of phosphines or phosphites in the same pot produces meta-substitu
- Deruer, Elsa,Coulibali, Siomenan,Boukercha, Saad,Canesi, Sylvain
-
p. 11884 - 11890
(2017/11/24)
-
- Characterization of a selective inverse agonist for estrogen related receptor α as a potential agent for breast cancer
-
The estrogen-related receptor α (ERRα) is an orphan nuclear receptor that plays a primary role in the regulation of cellular energy homeostasis and osteogenesis. It is reported that ERRα is widely expressed in a range of tissues and accumulating evidence has supported that the high expression of ERRα correlates with poor prognosis of various human malignancies, including breast, endometrium, colon, prostate and ovary cancers. Herein is described the discovery of a novel selective inverse agonist (HSP1604) of ERRα, but not of ERRβ and ERRγ, as determined using transient transfection luciferase reporter assay and a time-resolved fluorescence resonance energy transfer (TR-FRET) co-activator assay. HSP1604 potently inhibits ERRα transcriptional activity with IC50=1.47±0.17?μM in cell-based luciferase reporter assay and also decreases the protein level of ERRα and the mRNA levels of its downstream target genes such as pyruvate dehydrogenase kinase 4 (PDK4), pS2 and osteopontin. HSP1604 has also suppressed the proliferation of different human cancer cell lines and the migration of breast cancer cells with high expression of ERRα. Representative in vivo results show that HSP1604 suppresses the growth of human breast cancer xenograft in nude mice as doses at 30?mg/kg or 100?mg/kg administered every other day during 28-day period. HSP1604 thus has the potential both as a new agent to inhibit the growth of tumors and as a chemical probe of ERRα biology.
- Zhang, Liudi,Liu, Peihong,Chen, Haifei,Li, Qunyi,Chen, Lu,Qi, Huijie,Shi, Xiaojin,Du, Yongli
-
p. 439 - 448
(2016/08/17)
-
- Palladium-Catalyzed cascade sp2 c?H bond functionalizations allowing one-Pot access to 4?Aryl-1,2,3,4-tetrahydroquinolines from n?Allyl?N?arylsulfonamides
-
We have developed a palladium-catalyzed cascade reaction allowing an efficient synthesis of 4-aryl-1,2,3,4-tetrahydroquinolines from N-allyl-N-arylsulfonamides and benzenesulfonyl chlorides. In this transformation, two C(sp2)?C(sp3) bonds were formed via activation of C(sp2)?H bonds. The reaction proceeds using the easily accessible catalyst PdCl2, with Li2CO3 as inexpensive base and CuBr as additive, and tolerates a wide variety of substituents on both reaction partners.
- Yuan, Kedong,Soule, Jean-Francois,Dorcet, Vincent,Doucet, Henri
-
p. 8121 - 8126
(2018/05/23)
-
- A highly efficient heterogeneous copper-catalyzed Chan-Lam coupling reaction of sulfonyl azides with arylboronic acids leading to: N -arylsulfonamides
-
A heterogeneous Chan-Lam coupling reaction between sulfonyl azides and arylboronic acids was achieved in MeOH at room temperature in the presence of 10 mol% of an l-proline-functionalized MCM-41-immobilized copper(i) complex [MCM-41-l-proline-CuCl] under air, yielding a variety of N-arylsulfonamides in excellent yields. The new heterogeneous copper complex can be prepared from commercially readily available and inexpensive reagents, and recovered by simple filtration of the reaction solution and recycled at least 8 times without any decreases in activity.
- You, Chongren,Yao, Fang,Yan, Tao,Cai, Mingzhong
-
p. 43605 - 43612
(2016/05/24)
-
- Novel, potent, selective and cellular active ABC type PTP1B inhibitors containing (methanesulfonyl-phenyl-amino)-acetic acid methyl ester phosphotyrosine mimetic
-
Protein tyrosine phosphatase 1B (PTP1B) which plays an important role in the negative regulation of insulin and leptin pathway has emerged as a novel promising therapeutic target for the treatment of type 2 diabetes mellitus and obesity. Upon careful study, a series of novel scaffold and simple synthesis method inhibitors were discovered based on the analysis of X-ray crystal structures of PTP1B/inhibitor complexes and docking simulations. Among them, compound P7 exhibited high inhibitory activity (IC50 = 222 nM) with moderate selectivity (8-fold) over T-cell PTPase (TCPTP) through interacting with the A, B and C binding sites of PTP1B enzyme. Further studies on cellular activities revealed that compound P7 could enhance insulin-mediated IRβ phosphorylation and insulin-stimulated glucose uptake.
- Liu, Peihong,Du, Yongli,Song, Lianhua,Shen, Jingkang,Li, Qunyi
-
p. 7079 - 7088
(2015/11/11)
-
- Low catalyst loadings for ligand-free copper(I)-oxide-catalyzed N-arylation of methanesulfonamide in water
-
A simple and practical protocol for the cross-coupling of methanesulfonamide and aryl iodides under ligand-free copper(I)-oxide-catalyzed conditions in water is reported. The method allows the preparation of a wide variety of synthetically useful N-arylated methanesulfonamides in good to excellent yields (up to 90 %) under the optimized conditions. A convenient and efficient ligand-free method using a copper(I) oxide catalyst at 130 °C in water was developed for the N-arylation of methanesulfonamide with aryl iodides. A variety of functionalized aliphatic and cyclic sulfonamides were coupled with different substituted aryl halides to give the corresponding N-arylated products in good to excellent yields under the optimized conditions. Copyright
- Tan, Bryan Yong-Hao,Teo, Yong-Chua,Seow, Ai-Hua
-
p. 1541 - 1546
(2014/03/21)
-
- Low Catalyst Loadings for Ligand-Free Copper(I)-Oxide-Catalyzed N-Arylation of Methanesulfonamide in Water
-
A simple and practical protocol for the cross-coupling of methanesulfonamide and aryl iodides under ligand-free copper(I)-oxide-catalyzed conditions in water is reported. The method allows the preparation of a wide variety of synthetically useful N-arylated methanesulfonamides in good to excellent yields (up to 90 %) under the optimized conditions.
- Tan, Bryan Yong-Hao,Teo, Yong-Chua,Seow, Ai-Hua
-
p. 1541 - 1546
(2015/10/05)
-
- Mild hypervalent iodine mediated oxidative nitration of N-aryl sulfonamides
-
An oxidative and acid-free method for the nitration of N-aryl sulfonamides has been developed using a combination of sodium nitrite as cheap and easy to handle NO2-source and the hypervalent iodine reagent PIFA as stoichiometric oxidant. Under
- Kloeckner, Ulrich,Nachtsheim, Boris J.
-
supporting information
p. 10485 - 10487
(2014/09/29)
-
- Copper-catalyzed Chan-Lam Coupling between Sulfonyl Azides and Boronic acids at room temperature
-
A mild and efficient method for the synthesis of N-arylsulfonamides in the presence of 10 mol % of CuCl is demonstrated. The reaction proceeds readily at room temperature in an open flask using a variety of sulfonyl azides and boronic acids without any base, ligand, or additive.
- Moon, Soo-Yeon,Nam, Jungsoo,Rathwell, Kris,Kim, Won-Suk
-
supporting information
p. 338 - 341
(2014/04/03)
-
- Superacid synthesized tertiary benzenesulfonamides and benzofuzed sultams act as selective hCA IX inhibitors: Toward understanding a new mode of inhibition by tertiary sulfonamides
-
A series of tertiary (fluorinated) benzenesulfonamides was synthesized in superacid HF-SbF5. To circumvent the problem of the in situ iminium ion formation, proved by low temperature NMR experiments, a tandem superacid catalysed cross-coupling
- Metayer, Benoit,Martin-Mingot, Agnes,Vullo, Daniella,Supuran, Claudiu. T.,Thibaudeau, Sebastien
-
p. 7540 - 7549
(2013/11/06)
-
- A general method for palladium-catalyzed reactions of primary sulfonamides with aryl nonaflates
-
A general method for Pd-catalyzed sulfonamidation of aryl nonafluorobutanesulfonates (aryl nonaflates) is described. A biaryl phosphine ligand, t-BuXPhos, formed the most active catalyst, and K3PO 4 in tert-amyl alcohol was found to be the optimal base-solvent combination for the reaction. The reaction conditions were tolerant of various functional groups such as cyano, nitro, ester, aldehyde, ketone, chloride, carbamate, and phenol. Heterocyclic aryl nonaflates were found to be suitable coupling partners. High yields of the coupled products were obtained from the reactions between inherently disfavored substrates such as electron-rich nonaflates and electron-poor sulfonamides. Kinetic data suggest reductive elimination to be the rate-limiting step for the reaction. The only limitation of this methodology that we have identified is the inability of 2,6-disubstituted aryl nonaflates to efficiently participate in the reaction.
- Shekhar, Shashank,Dunn, Travis B.,Kotecki, Brian J.,Montavon, Donna K.,Cullen, Steven C.
-
experimental part
p. 4552 - 4563
(2011/07/31)
-
- Mild Pd-catalyzed N -arylation of methanesulfonamide and related nucleophiles: Avoiding potentially genotoxic reagents and byproducts
-
A convenient, general, and high yielding Pd-catalyzed cross-coupling of methanesulfonamide with aryl bromides and chlorides is reported. The use of this method eliminates concern over genotoxic impurities that can arise when an aniline is reacted with methanesulfonyl chloride. The application of this method to the synthesis of dofetilide is also reported.
- Rosen, Brandon R.,Ruble, J. Craig,Beauchamp, Thomas J.,Navarro, Antonio
-
supporting information; experimental part
p. 2564 - 2567
(2011/06/25)
-
- Copper-catalyzed cross-coupling of sulfonamides with aryl iodides and bromides facilitated by amino acid ligands
-
A highly general, convenient, and inexpensive catalyst system was developed for the N-arylation of sulfonamides with aryl iodides or bromides by using 5-20 mol % of CuI as catalyst, 20 mol % of N-methylglycine (for aryl iodides) or N,N-dimethylglycine (for aryl bromides) as ligand, and K3PO 4 as base.
- Deng, Wei,Liu, Lei,Zhang, Chen,Liu, Min,Guo, Qing-Xiang
-
p. 7295 - 7298
(2007/10/03)
-
- NOVEL BENSOPHENONE DERIVATIVES OR SALTS THEREOF
-
A benzophenone derivative represented by the following formula: whereinR1 represents, for example, an optionally substituted heterocyclic group, or a substituted phenyl group; Z represents, for example, an alkylene group; R2 represents, for example, a carboxyl group optionally protected with alkyl;R3 represents, for example, an optionally protected hydroxyl group; R4 represents, for example, an optionally substituted cycloalkyloxy group; and R5 represents, for example, a hydrogen atom, ???or a salt thereof has anti-arthritic activity, inhibits bone destruction caused by arthritis, and provides high safety and excellent pharmacokinetics and thus is useful as therapeutic agent for arthritis. These compounds have inhibitory effect on AP-1 activity and are useful as preventive or therapeutic agent for diseases in which excessive expression of AP-1 is involved.
- -
-
-
- A convenient reductive deamination (hydrodeamination) of aromatic amines
-
Reductive deamination (hydrodeamination) of aromatic amines can be conveniently carried out by amination of the corresponding arylamine methanesulfonamides using chloroamine under alkaline conditions. The intermediate aryl methanesulfonylhydrazines directly eliminate methanesulfinic acid, affording diazenes which extrude nitrogen affording the desired deaminated products. Both sulfonamide formation and reduction reactions occur in high yield and are compatible with a variety of functional groups.
- Wang,Guziec Jr.
-
p. 8293 - 8296
(2007/10/03)
-
- A practical route to quinolines from anilines
-
A practical route to quinoline from anilines through acid-mediated cyclization of 3-(N-aryl-N-sulfonylamino)propionaldehydes has been developed. Treatment of the cyclization products, dihydroquinoline intermediates with KOH in DMSO leads to substituted quinolines.
- Tokuyama, Hidetoshi,Sato, Masashi,Ueda, Toshihiro,Fukuyama, Tohru
-
p. 105 - 108
(2007/10/03)
-
- Reactivity and mechanism in the hydrolysis of β-sultams
-
β-Sultams show extraordinary rate enhancements of 109-and 107-fold, respectively, compared with the acid-and base-catalyzed hydrolysis of corresponding acyclic sulfonamides. They are about 103-fold more reactive than analogous β-lactams. The alkaline hydrolysis of some β-sultams shows a rate term that is second-order in hydroxide ion concentration, which is indicative of a stepwise mechanism involving a trigonal bipyramidal intermediate (TBPI). The Bronsted βlg value for the alkaline hydrolysis of N-aryl-β-sultams is -0.58 and the kinetic solvent isotope effect kH2OOH/kD2OOD is 0.60, compatible with rate-limiting formation of the TBPI. Conversely, kH2OOH/kD2OOD for N-alkyl-β-sultams is 1.55, indicative of rate-limiting breakdown of the TBPI. The acid-catalyzed hydrolysis of β-sultams is strongly retarded by electron-withdrawing groups α to the sulfonyl group, and it is suggested that the mechanism may involve unimolecular ring opening to generate a sulfonylium ion. The Bronsted βlg value for the acid-catalyzed hydrolysis of N-benzyl-β-sultams is 0.32. The general-acid-catalyzed hydrolysis of N-benzyl-β-sultam by carboxylic acids shows a Bronsted α value of 0.67 and is attributed to a specific acid-nucleophilic mechanism with the formation of a mixed-anhydride intermediate.
- Baxter, Nicholas J.,Rigoreau, Laurent J. M.,Laws, Andrew P.,Page, Michael I.
-
p. 3375 - 3385
(2007/10/03)
-
- THE SYNTHESIS OF SULFUROUS DIAMIDE HETEROCYCLES THROUGH THE CYCLOADDITION REACTION OF N-SULFINYLANILINES WITH BENZALANILINES
-
The cycloaddition reaction of N-sulfinylanilines - serving as "dienes" - with aromatic Schiff bases provides a convenient access to the thiadiazine oxide system (3).
- Zoller, Uri,Rona, Peter
-
p. 2813 - 2814
(2007/10/02)
-
- Cyclization of 2-acetaldehyde Diethyl Acetals to Indoles. Evidence for Stereoelectronic Effects in Intramolecular Electrophilic Aromatic Substitution
-
Methanesulfonamides of N-(2,2-diethoxyethyl)anilines can be cyclized to indoles in aromatic solvents by reaction with titanium tetrachloride.The temperature of the cyclization is substituent dependent, occurring at 0 deg C for the m-methoxy derivative but requiring 130 deg C for the p-bromo compound.Yields are good for various alkoxy-, alkyl-, and haloindoles, ranging from 60percent to 90percent.Meta-substituted reactants give rise to mixtures of 4- and 6-substituted indoles in which the 6-substituted product dominates by 2-4:1.The cyclization fails for ortho-substituted reactants.The major reaction process is N-dealkylation in the case of ortho-substituted compounds.An analogous cyclization occurs with the methanesulfonamides of N-(3,3-diethoxypropyl)anilines to give 1-(methylsulfonyl)-4-chloro-1,2,3,4-tetrahydroquinolines.This cyclization is much more rapid than for the five-membered ring closure leading to indoles and indicates a substantial rate retardation due to stereoelectronic effects in the indole cyclization.Ortho substitution also prevents cyclization in the six-membered-ring case.
- Sundberg, Richard J.,Laurino, Joseph P.
-
p. 249 - 254
(2007/10/02)
-
- Substituent effects in infrared spectroscopy-VII. Meta and para substituted methanesulphonanilides
-
Substituent effects on the NH frequencies of the conformers of methanesulphonanilides, their cyclic dimers and their hydrogen bonded complexes with acetonitrile have been analysed by means of the Hammet equation.An electron-withdrawing substituent may either increase or decrease ν(NH) in the XC6H4NHY series according to the electronic nature of the Y group.This can be explained by the non-monotonic dependence of the NH stretching frequency on the ionic character of the NH bond.
- Laurence, C.,Berthelot, M.,Lucon, M.,Tsuno, Y.
-
p. 791 - 796
(2007/10/02)
-