- Polyethylene Glycol (PEG-400) as Methylene Spacer and Green Solvent for the Synthesis of Heterodiarylmethanes under Metal-Free Conditions
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Polyethylene glycol 400 (PEG-400) has been employed as a green, biodegradable solvent as well as methylene spacer for the one-pot synthesis of heterodiarylmethanes under metal-free conditions. PEG-400 is used for the dimerization of both symmetrical and unsymmetrical fused heterocycles and arenes as methylene spacer. The reaction was facilitated by (diacetoxyiodo)benzene (PIDA) as an oxidant. This reaction proceeds without transition metal, base, ligand, and under additive-free conditions involving the coupling of sp3 and sp2-hybridized carbon atoms. The method is applicable for variety of heterocycles such as imidazopyridines, imidazothioazoles, imidazobenzothiozoles, indolizines, indole, 1-methyl-1H-indole, N,N-dimethylaniline and trimethoxybenzene. Good to excellent yields and applicability to gram-scale synthesis demonstrate the potential scope of the process for commercial/industrial applications.
- Kumar, Rahul,Rawat, Deepa,Adimurthy, Subbarayappa
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- Reduction of Carboxylic Acid Derivatives by BH4(1-) in Acidic Dimethyl Sulfoxide
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Carboxylic acid amides of all degrees of substitution, both aliphatic and aromatic, can be reduced to the corresponding primary, secondary or tertiary amines in good yield by a combination of NaBH4 and CH3SO2OH in dimethyl sulfoxide.The procedure also reduces aliphatic carboxylic acids and their esters to primary alcohols, but not conjugated aromatic acids.Crotonic acid is readily reduced to butanol.Isolated double bonds and nitriles also react, but the major products are not those of simple reduction.Michler's ketone is reduced to4,4'-bis(dimethylamino)diphenylmethane.The acid probably facilitates the amide reduction by protonating the carbonyl oxygen.The mechanism of the other reductions is less clear.The method does not require an anhydrous solvent, does not involve a hazardous reagent, has somewhat different selectivity than techniques in general use, and may sometimes be the method of choice.
- Wann, Steven R.,Thorsen, Peter T.,Kreevoy, Maurice M.
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- Light-promoted N,N-dimethylation of amine and nitro compound with methanol catalyzed by Pd/TiO2 at room temperature
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A series of TiO2 supported nano-Pd catalysts (Pd/TiO2) were prepared and used for the N,N-dimethylation of different amines and nitro compounds with methanol under UV irradiation at room temperature. A wide range of N,N-dimethyl amines were one-pot synthesized with up to 98% by applying aliphatic secondary amines, aromatic primary amines, aliphatic primary amines and aromatic nitro compounds as starting materials. It is noteworthy that up to 90% yield of 4-chloro-N,N-dimethylaniline was obtained by adjusting the Pd loadings on the TiO2 and the dehalogenation reaction was inhibited. Finally, a reaction mechanism is discussed, involving PhN = CH2 and PhNHCH3 as reaction intermediates.
- Zhang, Lina,Zhang, Yan,Deng, Youquan,Shi, Feng
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- Novel formaldehyde-mediated dimerization reaction of n-alkyl-1-naphthylamine derivatives under mild/neutral conditions; application to synthesis of naphthylamine-derived macrocycles
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The dimerization reaction of N-methyl-1-naphthylamine (1) with formaldehyde is described. Reaction of 1 with formaldehyde under mild/neutral conditions gave bis-4-(1-N-methylaminonaphthyl)methane (2) in high yield as a single dimerization product. This formaldehyde-mediated aromatic condensation reaction is chemo- and regio-selective, and it takes place particularly with N-monoalkyl-1-naphthylamines as substrates. The novel naphthylamine-derived macrocyclic compounds 1,6,28,33-tetraaza-[6.1.6.1]paranaphthalenophane (13a) and 1,13-diaza[13,1]paranaphthalenophane (12c) were synthesized by application of this formaldehyde-mediated mild/neutral condensation reaction as the key step.
- Takahashi, Hiroyasu,Hashimoto, Yuichi,Nagazawa, Kazuo
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- Kinetics and mechanism of the reactions of amine boranes with carbenium ions
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The kinetics of the reactions of trialkylamine boranes and pyridine boranes with benzhydryl cations have been determined photometrically. Second-order rate laws are obeyed, first-order with respect to amine borane concentration and first-order with respect to carbocation concentration. As for other reactions of carbocations with neutral nucleophiles, the rates of these reactions are only slightly affected by solvent polarity. The structure-reactivity relationships and kinetic isotope effects are in accord with a polar mechanism proceeding through a transition state where the migrating hydride is partly bound to the entering carbon and to the leaving boron atom. The rate constants correlate linearly with the electrophilicity parameters E. of the carbenium ions. It is therefore possible to use the linear free enthalpy relationship logk2 = s(E+N) for determining nucleophilicity parameters N for the amine boranes and to compare their hydride-donating abilities with those of other non-charged hydride donors (silanes, germanes, stannanes, and dihydropyridines).
- Funke, Marcus-A.,Mayr, Herbert
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- Photochemical Trifluoromethylation of Some Aromatic and Heteroaromatic Compounds with Trifluoromethyl Bromide
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The photochemical introduction of trifluoromethyl group with CF3Br in aromatic and heteroaromatic rings was investigated for 9 compounds.Naphthalene, anthracene, anisole, N,N-dimethylaniline, ferrocene, benzothiophene, isoquinoline, and N-methylpyrrole gave trifluoromethylated products in 6.5-100percent yields.In one step from uracil, a pharmacologically important 5-trifluoromethyluracil can be synthesized by this method in 11percent yield.Based on the mechanistic study carried out for the naphthalene-CF3Br-CH3CN system, the reaction is found to proceed via the electron transfer from an excited singlet state of naphthalene to CF3Br.
- Akiyama, Takeo,Kato, Kohji,Kajitani, Masatsugu,Sakaguchi, Yoshio,Nakamura, Junko,et al.
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- Photochemical Reaction of Diaryliodonium Salts with Dimethylaniline
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A solution of 4,4'-dimethyldiphenyl iodonium tettrafluoroborate and N,N-dimethylaniline in acetonitrile is irradiated by UV light to give iodotoluene, toluene, 4,4'-methylenebis(N,N-dimethylaniline), crystal violet, methyl violet. KEY WORDS: 4,4'-dimethyldiuphenyl iodonium salt; N,N-dimethylaniline; 4,4'-methylenebis(N,N-dimethylaniline); crystal violet; methyl violet.
- Bi, Yubai,Neckers, Douglas C.
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- Scope and Mechanisms of Frustrated Lewis Pair Catalyzed Hydrogenation Reactions of Electron-Deficient C￡C Double Bonds
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Several phosphonium and ammonium triarylborohydrides, which are intermediates in hydrogenation reactions catalyzed by frustrated Lewis pairs, were synthesized in high yield under mild conditions from triaryl boranes, ammonium or phosphonium halides, and triethylsilane. The kinetics and mechanisms of the reactions of these hydridoborate salts with benzhydrylium ions, iminium ions, quinone methides, and Michael acceptors were investigated, and their nucleophilicity was determined and compared with that of other hydride donors.
- Morozova, Varvara,Mayer, Peter,Berionni, Guillaume
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- Stopped-flow Kinetic Study of the Formation and Decay of the 4,4'-(Dimethylamino)diphenylmethane Radical Cation in Aqueous Solution
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The oxidation kinetics of 4,4'-(dimethylamino)diphenylmethane (DMADPM) by Ce(IV), by the oxoanions, MnO4(1-) and Cr2O7(2-), by peroxides, namely, peroxomonosulfate, peroxodisulfate and H2O2, and by halogens viz., Cl2, Br2 and I2, to the radical cation, DMADPM.(1+) along with further oxidation to the product monocation DMADPM(1+) have been studied by the stopped-flow technique.The first- and second-stage oxidations have been followed by monitoring the formation and decay of DMADPM.(1+) via the absorption at 610 nm.Both formation and decay of DMADPM.(1+) obey total second-order kinetics, first-order each with respect to or .(1+)> and .The effects of pH and temperature have also been investigated on the formation and decay of DMADPM.(1+) and the kinetic and transition-state parameters have been evaluated and discussed with suitable reaction mechanisms.DMADPM.(1+) was converted back into the DMADPM by the following reducing agents; ascorbic acid, dithionite, metabisulfite, sulfite and thiosulfate.The rate constants for these reactions were estimated.The experimentally determined rate constants for the oxidative electron-transfer reactions were correlated theoretically using Marcus theory and the observed and calculated rate constants show good agreement.
- Aravindan, Ponnu,Maruthamuthu, Pichai,Dharmalingam, Periasamy
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- Full N,N-Methylation of 4,4′-Methylenedianiline with Dimethyl Carbonate: A Feasible Access to 4,4′-Methylene bis(N,N-Dimethylaniline)
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The full N,N-methylation of 4,4′-methylenedianiline (MDA) with dimethyl carbonate (DMC) was investigated. The yield of the major product 4,4′-methylene bis(N,N-dimethylaniline) (MBDMA) reached as high as 97% over NaY catalyst at 190°C for 6 h. The catalyst could be used for two more times with acceptable MBDMA yields higher than 90%. The main by-products were identified as three N-methylated derivatives. Surprisingly, the formation of the N-methoxycarbonylation product was extremely restrained, which could be produced in high yields of 98% on zinc acetate catalyst. Furthermore, the reaction pathway to the major product MBDMA was proposed. Finally, a feasible synthetic route of 4,4′-methylene bis(N,N-dimethylaniline) (MBDMA) was established, featuring a high yield, mild reaction conditions, and simple operations.
- Qiu, Zegang,Wang, Kunjie,Li, Zhiqin,Li, Tao,Bai, Jinhao,Yin, Chanjuan,Ye, Xiushen,Liu, Haining
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- An efficient approach to 1,3,5-tris-arylhexahydro-1,3,5-triazines
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In this paper we report a facile and efficient procedure for the synthesis of 1,3,5-tris-arylhexahydro-1,3,5-triazines (3) by reaction of anilines 1 with 1,3,6,8-tetrazatricyclo[4.4.1.13,8]-dodecane (TATD) (2). The diequatorial chair conformational preference of 3b (Ar=p-tolyl) in the solid state was established by X-ray crystallography and agrees well with molecular mechanics calculations.
- Rivera, Augusto,Torres, Olga Lucia,Leiton, Jesus D.,Morales-Rios, Martha S.,Joseph-Nathan, Pedro
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- An experimental and theoretical study on the preparation of 4,4′-methylene-bis(N,N-dimethylaniline) in ionic liquid
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The reaction of N,N-dimethylaniline with tetrachloromethane in ionic liquid was found to give 4,4′-methylene-bis (N,N-dimethylaniline) in considerable yield. The ionic liquid was prepared from N,N-dimethylaniline which is also the one of raw materials for the preparation of 4,4′-methylene-bis (N,N-dimethylaniline), and acts as both solvent and catalyst in the reaction. Mild reaction conditions, enhanced rates, improved yields, and reagents' reactivity which is different from that in conventional organic solvents are the remarkable features observed in ionic liquids. In addition, the results of calculations are in good accordance with the experimental outcomes.
- Wang, Yun
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- Novel reaction of dimethylaniline with tetrabromomethane producing 4,4′-methylenebis(N,N-dimethylaniline)
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Reaction of N,N-dimethylaniline (1) with tetrahalomethanes such as tetrabromomethane and tetrachloromethane in acetonitrile was found to give 4,4′-methylenebis(N,N-dimethylaniline) (2) in considerable yield. The reaction is considered to be initiated by t
- Matsubara, Yoshio,Matsuda, Takuya,Kato, Atsuhisa,Kakedai, Yoshikatsu,Yamaguchi, Yoshihiro
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- HYDRIDE TRANSFER REACTIONS OF MICHLER'S HYDRIDE WITH DIFFERENT ?-ACCEPTORS
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The hydride transfer reactions of 4,4'-bis(dimethylaminophenyl)methane (Michler's hydride) with p-benzoquinones were studied.The rate of formation of Michler's Hydrol Blue was followed spectrophotometrically.The second-order rate constants and the activation parameters were estimated.The formation of a charge-transfer complex was observed at low temperatures.Stable and unstable paramagnetic species formed during the reactions were assigned by ESR spectroscopy.The observed kinetic behaviour and the stoichiometry were in line with those previously obtained for the systems involving Leuco Crystal Violet, Leuco Malachite Green and Leuco Bindshedler's Green.Hence the reaction is considered to proceed according to the so-far accepted multi-step mechanism.However, when tetracyano-p-quinodimethane or tetracyanoethylene was used as a ?-acceptor, a comparatively stable radical ion pair was formed as a result of a one-electron transfer, followed by the gradual formation of Michler's Hydrol Blue.The kinetic behaviour and the stoichiometry of the reaction were examined, together with the enhanced kinetic effects of added triethylamine.A modified mechanism for these systems is proposed.The role of cyanomethylenes was found to be essentially different from that of p-benzoquinones, and therefore ?-acceptors are divided into two groups of cyanomethylenes and p-benzoquinones.
- Zaman, Khan. M.,Nishimura, Norio,Yamamoto, Shunzo,Sueishi, Yoshimi
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- NBu4NI-catalyzed C3-formylation of indoles with N-methylaniline
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nBu4NI-catalyzed C3-selective formylation of N-H and N-substituted indoles by using N-methylaniline as a formylating reagent was first successfully demonstrated.
- Li, Lan-Tao,Huang, Juan,Li, Hong-Ying,Wen, Li-Juan,Wang, Peng,Wang, Bin
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- Additive-free selective methylation of secondary amines with formic acid over a Pd/In2O3 catalyst
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Formic acid is used as the sole carbon and hydrogen source in the methylation of aromatic and aliphatic amines to methylamines. The reaction proceeds via a formylation/transfer hydrogenation pathway over a solid Pd/In2O3 catalyst without the need for any additive.
- Benaissa, Idir,Cantat, Thibault,Genre, Caroline,Godou, Timothé,Pinault, Mathieu
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- K2S2O8-induced site-selective phenoxazination/phenothiazination of electron-rich anilines
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By just using cheap K2S2O8 as the oxidant at room temperature in the air, the phenoxazination/phenothiazination of electron-rich anilines to construct or modify triarylamine derivatives has been established. This method demonstrates complete para-selective amination under catalyst-free conditions and its simplicity and efficiency lead to good performance in flow-chemistry synthesis.
- Lei, Aiwen,Wang, Pengjie,Wang, Shengchun,Wang, Xiaoyu,Yi, Hong,Zhang, He,Zhang, Heng
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supporting information
p. 147 - 151
(2022/01/19)
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- C-Methylenation of anilines and indoles with CO2and hydrosilane using a pentanuclear zinc complex catalyst
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The one-stepC-methylenation of anilines and indoles with CO2and phenylsilane was catalyzed by a pentanuclear ZnIIcomplex to give diarylmethanesviageminal C-H and C-C bond formation. It is proposed that the zinc-hydride complex generatedin situis a catalytically active species and that bis(silyl)acetal is a key intermediate. When aniline was used as a substrate, both theC-methylenation andN-methylation proceeded.
- Ema, Tadashi,Kosugi, Hiroyasu,Nishimura, Ritsuki,Takaishi, Kazuto,Yamada, Yuya
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supporting information
p. 8083 - 8086
(2021/08/20)
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- Electro-oxidative C(sp2)-H/O-H cross-dehydrogenative coupling of phenols and tertiary anilines for diaryl ether formation
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The formation of diaryl ethers is generally achievedviatransition metal catalyzed etherification reactions (Ullmann, Chan-Lam, Buchwald-Hartwig) with prefunctionalized aryl halide substrates at elevated temperatures. Herein, we report a protocol for electrochemical C(sp2)-H/O-H cross-dehydrogenative coupling of phenols and tertiary anilines to synthesize diaryl ethers. The C(sp2) H/O-H coupling product can be obtained under metal- and oxidant-free conditions at room temperature in moderate to excellent yield (up to 83% yield) with high regioselectivity (>99% forpara-substitution) and with a broad substrate scope (22 examples).
- Tang, Hongyang,Smolders, Simon,Li, Yun,De Vos, Dirk,Vercammen, Jannick
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p. 3925 - 3930
(2021/06/18)
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- Nitrosoarene-catalyzed regioselective aromatic C-H sulfinylation with thiols under aerobic conditions
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Aromatic amines and (hetero)arenes, such as indoles and pyrroles, are regioselectively sulfinylated under mild aerobic conditions using nitrosoarenes as a redox-catalyst. The nitrosoarene is involved in the electron transfer process with arenes to generate a crucial arene radical cation intermediate for C-H sulfinylation. The present methodology requires no directing group, can be scaled up easily and is applicable for the late-stage functionalization of drug molecules and natural products with high regioselectivity.
- Chatterjee, Indranil,Patel, Sandeep,Pradhan, Suman
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supporting information
p. 5054 - 5057
(2020/05/18)
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- Highly Efficient Binuclear Copper-catalyzed Oxidation of N,N-Dimethylanilines with O2
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A binuclear copper-salicylate complex, [Cu(Sal)2(NCMe)]2 (Sal=salicylate), was found to be an active catalyst for the oxidation of N,N-dimethylanilines by O2, affording the corresponding N-methyl-N-phenylformamides as major products. The reactions were carried out with a O2 balloon and the S/C (substrate/catalyst ratio) of the model reaction could be up to 1×105, providing a practical and highly efficient catalytic protocol for accessing N-methyl-N-phenylformamides.
- Liu, Yuxia,Yan, Yonggang,Xue, Dong,Wang, Zhongfu,Xiao, Jianliang,Wang, Chao
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p. 2221 - 2225
(2020/03/23)
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- Method for continuously preparing bis-(4-N,N-dimethyl aminophenyl)methane in micro-channel reactor
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The invention discloses a method for continuously preparing bis-(4-N,N-dimethyl aminophenyl)methane in a micro-channel reactor. The method includes the steps of firstly, preparing a raw material 1, wherein a catalyst is added to a formaldehyde solution to prepare the raw material 1; secondly, putting the raw material 1 and N,N-dimethylaniline into a preheating module of the micro-channel reactor through a metering pump to be preheated, controlling the molar ratio and preheating time of the two raw materials by controlling the flowing velocity of the metering pump, making the two raw materialspass through the preheating module and enter a reaction module for reaction, and keeping the reaction temperature and the preheating temperature of the preheating module consistent; thirdly, making areaction product directly flow into ice water, and separating out solid, conducting filtering, washing, recrystallizing and depressurized drying to obtain a product. The reaction temperature, the molar ratio of the raw materials, the reaction dwell time and the like are precisely controlled, the heat exchange efficiency is high, the system is evenly heated, the reaction temperature can be precisely controlled through an external heat exchanger, the reaction can be started and stopped at any time, and no amplification effect is realized.
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Paragraph 0016-0030
(2019/10/01)
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- Functional Ionic Liquids as Efficient and Recyclable Catalysts for the Methylation of Formaldehyde with Aromatics
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Abstract: Methylation of formaldehyde with various aromatics under functional ionic liquids catalysis has been developed. Among the ionic liquids investigated, triphenyl-(4-sulfobutyl)-phosphonium triflate ([TTPBs][CF3SO3]) showed high activity and afforded excellent yields of diarylmethane derivatives. A mechanism for the catalytic performance of [TTPBs][CF3SO3] is proposed. Besides, the catalyst can simply be separated from the reaction mixture by centrifugation and be recycled ten times without noticeable loss of activity. Graphical Abstract: Diarylmethane derivatives were successfully synthesized from the methylation of formaldehyde with aromatics using efficient and recyclable functional ionic liquids as catalysts, excellent yields and selectivities were obtained under solvent free conditions. The catalyst was reused at least ten consecutive recycles without noticeable loss in its catalytic activity. Meanwhile, the usability of catalyst was explored.[Figure not available: see fulltext.]
- Song, Heyuan,Jin, Fuxiang,Jin, Ronghua,Kang, Meirong,Li, Zhen,Chen, Jing
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p. 1264 - 1272
(2016/07/06)
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- Substituted tetraphenyl porphyrin catalyzed oxidative N-dealkylation of tertiary amine using molecular oxygen
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Oxidative N-dealkylation of NN-dimethylaniline catalyzed by substituted tetraaryl porphyrin complexes of iron and manganese with molecular oxygen, gave a mixture of dealkylated, monooxygenated and dimerised compounds as products. Presence of substituents on the catalyst effects nature and yield of products formed. One electron transfer route [E T) predominated over H-atom abstraction [HAT] in most of the reactions.
- Agarwal, Dau. D.,Bhat, Daisy
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p. 689 - 693
(2016/08/30)
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- Zinc oxide surface: a versatile nanoplatform for solvent-free synthesis of diverse isatin derivatives
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Multicomponent reactions performed on the surface of nanostructured zinc oxide gave 3,3-bis(indolyl)indolin-2-one and xanthene derivatives with excellent yields. Both Lewis acidic (Zn2+) and basic (O2?) sites on the surface of zinc oxide were utilized to perform the aforementioned transformations. The significance of surface catalysis was further proved by performing the experiment with surface masked zinc oxide. The developed zinc oxide nanocatalyst was reusable up to five times without significant loss in its activity.
- Kothandapani, Jagatheeswaran,Ganesan, Asaithampi,Mani, Ganesh Kumar,Kulandaisamy, Arockia Jayalatha,Rayappan, John Bosco Balaguru,Selva Ganesan, Subramaniapillai
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supporting information
p. 3472 - 3475
(2016/07/18)
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- Highly regioselective para-methylthiolation/bridging methylenation of arylamines promoted by NH4I
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Aryl methyl thioethers and methylene-bridged arylamines were synthesized via highly regioselective para-methylthiolation/bridging methylenation of arylamines using DMSO as the methylthio or methylene source in the presence of NH4I under metal-free conditions. For the substrates with both electron-donating and electron-withdrawing substituents, the reaction proceeded smoothly and gave moderate to good yields.
- Xu, Yinfeng,Cong, Tiantian,Liu, Ping,Sun, Peipei
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supporting information
p. 9742 - 9745
(2015/10/05)
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- Iron-catalyzed aerobic oxidative amidation of tertiary amines with carboxylic acids
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An oxidative amidation of tertiary amines with carboxylic acids has been developed in the presence of FeCl3·6H2O as catalyst and oxygen as oxidant. A variety of tertiary amides were obtained in good to excellent yields from inexpensive and readily available reagents. The possible reaction pathways were investigated.
- Ma, Lina,Li, Yuanming,Li, Zhiping
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p. 1310 - 1315
(2015/03/18)
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- Unexpected C=N bond formation via NaI-catalyzed oxidative de-tetra-hydrogenative cross-couplings between N,N-dimethyl aniline and sulfamides
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A direct and convenient C=N bond formation reaction was reported, which was a de-tetra-hydrogenative cross-coupling (DTCC) reaction between N,N-dimethyl aniline and sulfamide under transition-metal-free conditions, and to give sulfonyl amidine derivatives in moderate to high yields.
- Zheng, Yang,Mao, Jincheng,Chen, Jie,Rong, Guangwei,Liu, Defu,Yan, Hong,Chi, Yongjian,Xu, Xinfang
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p. 50113 - 50117
(2015/06/25)
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- Redox inactive metal ion triggered N-dealkylation by an iron catalyst with dioxygen activation: A lesson from lipoxygenases
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Utilization of dioxygen as the terminal oxidant at ambient temperature is always a challenge in redox chemistry, because it is hard to oxidize a stable redox metal ion like iron(iii) to its high oxidation state to initialize the catalytic cycle. Inspired by the dioxygenation and co-oxidase activity of lipoxygenases, herein, we introduce an alternative protocol to activate the sluggish iron(iii) species with non-redox metal ions, which can promote its oxidizing power to facilitate substrate oxidation with dioxygen, thus initializing the catalytic cycle. In oxidations of N,N-dimethylaniline and its analogues, adding Zn(OTf)2 to the [Fe(TPA)Cl2]Cl catalyst can trigger the amine oxidation with dioxygen, whereas [Fe(TPA)Cl2]Cl alone is very sluggish. In stoichiometric oxidations, it has also been confirmed that the presence of Zn(OTf)2 can apparently improve the electron transfer capability of the [Fe(TPA)Cl2]Cl complex. Experiments using different types of substrates as trapping reagents disclosed that the iron(iv) species does not occur in the catalytic cycle, suggesting that oxidation of amines is initialized by electron transfer rather than hydrogen abstraction. Combined experiments from UV-Vis, high resolution mass spectrometry, electrochemistry, EPR and oxidation kinetics support that the improved electron transfer ability of iron(iii) species originates from its interaction with added Lewis acids like Zn2+ through a plausible chloride or OTf- bridge, which has promoted the redox potential of iron(iii) species. The amine oxidation mechanism was also discussed based on the available data, which resembles the co-oxidase activity of lipoxygenases in oxidative dealkylation of xenobiotic metabolisms where an external electron donor is not essential for dioxygen activation.
- Zhang, Jisheng,Wang, Yujuan,Luo, Nengchao,Chen, Zhuqi,Wu, Kangbing,Yin, Guochuan
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p. 9847 - 9859
(2015/06/08)
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- Cu-catalyzed oxidative Povarov reactions between N-alkyl N-methylanilines and saturated oxa- and thiacycles
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Cu-catalyzed oxidative Povarov reactions between N,N-dialkylanilines and saturated oxa- or thiacycles with tert-butyl hydroperoxide (TBHP) are described; notably, the reactions use neither [4π] nor [2π]-motifs as the initial reagents. The use of cheap alkane-based substances as building units is of mechanistic and practical interest as two inert sp3 C-H bonds are activated.
- Kawade, Rahul Kisan,Huple, Deepak B.,Lin, Rong-Jing,Liu, Rai-Shung
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supporting information
p. 6625 - 6628
(2015/04/14)
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- Alkylation of aniline with methanol in the presence of FeCl 3·6H2O in carbon tetrachloride
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The reaction of aniline with methanol in the presence of FeCl 3·6 H2O in carbon tetrachloride leads to the formation of N-methyl- and N,N-dimethylanilines and 4,4′-methylenebis(N,N- dimethylaniline).
- Khusnutdinov,Bayguzina,Aminov
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p. 1447 - 1450
(2014/01/06)
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- Transition-metal-free synthesis of unsymmetrical diaryl chalcogenides from arenes and diaryl dichalcogenides
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A transition-metal-free synthetic method has been developed for the synthesis of unsymmetrical diaryl chalcogenides (S, Se, and Te) from diaryl dichalcogenides and arenes under oxidative conditions by using potassium persulfate at room temperature. Variously substituted arenes such as anisole, thioanisole, diphenyl ether, phenol, naphthol, di- and trimethoxy benzenes, xylene, mesitylene, N,N-dimethylaniline, bromine-substituted arenes, naphthalene, and diaryl dichalcogenides underwent carbon-chalcogen bond-forming reaction to give unsymmetrical diaryl chalcogenides in trifluoroacetic acid. To understand the mechanistic part of the reaction, a detailed in situ characterization of the intermediates has been carried out by 77Se NMR spectroscopy by using diphenyl diselenide as the substrate. 77Se NMR study suggests that electrophilic species ArE+ is generated by the reaction of diaryl dichalcogenide with persulfate in trifluoroacetic acid. The electrophilic attack of arylchalcogenium ion on the arene may be responsible for the formation of the aryl-chalcogen bond.
- Prasad, Ch Durga,Balkrishna, Shah Jaimin,Kumar, Amit,Bhakuni, Bhagat Singh,Shrimali, Kaustubh,Biswas, Soumava,Kumar, Sangit
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p. 1434 - 1443
(2013/03/29)
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- Towards a comprehensive hydride donor ability scale
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Rates of hydride transfer from several hydride donors to benzhydrylium ions have been measured at 20 °C and used for the determination of empirical nucleophilicity parameters N and sN according to the linear free energy relationship log k20 °C=sN(N+E). Comparison of the rate constants of hydride abstraction by tritylium ions with those calculated from the reactivity parameters sN, N, and E showed fair agreement. Therefore, it was possible to convert the large number of literature data on hydride abstraction by tritylium ions into N and sN parameters for the corresponding hydride donors, and construct a reactivity scale for hydride donors covering more than 20 orders of magnitude.
- Horn, Markus,Schappele, Ludwig H.,Lang-Wittkowski, Gabriele,Mayr, Herbert,Ofial, Armin R.
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p. 249 - 263
(2013/02/25)
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- Synthesis of benzidine derivatives via FeCl3·6H 2O-promoted oxidative coupling of anilines
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Under open-flask conditions in the presence of commercially available FeCl3·6H2O, N,N-disubstituted anilines can be converted into diversely functionalized benzidines with yields of up to 99%. Oxidative coupling was extended to N-monosubstituted anilines, and the method was applied to the efficient preparation of 6,6′-biquinoline. Mechanistic investigations have also been performed to explain the observed reactivities.
- Ling, Xuege,Xiong, Yan,Huang, Ruofeng,Zhang, Xiaohui,Zhang, Shuting,Chen, Changguo
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p. 5218 - 5226
(2013/07/25)
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- Efficient synthesis of Bis(4-Dimethaminophenyl)arylmethanes and Bis(4-Diamethaminophenyl)alkanes using iodine reagent
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A novel synthetic utility of NaICl2 for the preparation of bis(4-dimethaminophenyl)arylmethanes and bis(4-dimethaminophenyl)alkanes is described. In the presence of an aqueous solution of NaICl2, the reaction of arenes with aromatic aldehydes gives corresponding triarylmethane derivatives regioselectively in moderate to good yields. The method is also useful for the preparation of diarylalkane derivatives by using aliphatic aldehydes. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Bachhav, Harshal M.,Takale, Balaram S.,Telvekar, Vikas N.
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p. 1909 - 1914
(2013/05/21)
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- Electrophilic fluorination of N,N-dimethylaniline, N,N-dimethylnaphthalen- 1-amine and 1,8-bis(dimethylamino)naphthalene with N-F reagents
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Reaction of N,N-dimethylaniline, N,N-dimethylnaphthalen-1-amine and 1,8-bis(dimethylamino)- naphthalene (proton sponge) with 1-chloromethyl-4- fluorodiazonia-bicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor) and N-fluorobenzenesulfonimide (NFSI) h
- Sorokin, Vladimir I.,Pozharskii, Alexander F.,Ozeryanskii, Valery A.
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- Synthesis of N,N,N',N'-tetraalkylbenzidines through oxidative coupling of N,N-dialkylarylamines induced by SbCl5
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The oxidative coupling to 4,4'-N,N,N',N'-tetraalkylbenzidines is the main reaction observed during a study on the reactivity of N,N-dialkylanilines with SbCl5. A possible reaction mechanism is presented and discussed in comparison with the N,N-dialkylanilines oxidative coupling achieved with other Lewis acids. ARKAT-USA, Inc.
- Vitale, Paola,Di Nunno, Leonardo,Scilimati, Antonio
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- Copper(II)-catalyzed C-H (sp3) oxidation and C-N cleavage: Synthesis of methylene-bridged compounds using TMEDA as a carbon source in water
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A green, simple, and efficient protocol for the selective methylenation via CuCl2/oxygen-mediated C-H (sp3) oxidation and C-N cleavage using tetramethylethylenediamine (TMEDA) as a carbon source has been developed. The reactions were achieved in green solvent water under atmospheric conditions. The protocol exhibited a broad substrate scope including indoles, anilines, pyrroles and 1,3-dicarbonyls. Furthermore, two key intermediates of the reaction were successfully identified and the mechanism was explored. The Royal Society of Chemistry 2013.
- Zhao, Dan,Wang, Yue,Zhu, Min-Xue,Shen, Qi,Zhang, Lei,Du, Yun,Li, Jian-Xin
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p. 10272 - 10276
(2013/09/02)
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- Cu(ii)-catalyzed C-H (SP3) oxidation and C-N cleavage: Base-switched methylenation and formylation using tetramethylethylenediamine as a carbon source
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Base-switched methylenation and formylation using tetramethylethylenediamine (TMEDA) as a carbon source have been achieved under mild conditions, catalyzed by CuCl2, with atmospheric oxygen as oxidant. Bisindolylmethanes, diphenylmethanes and 3-formylindoles were synthesized with excellent regioselectivity and good yield.
- Zhang, Lei,Peng, Chen,Zhao, Dan,Wang, Yue,Fu, Hai-Jian,Shen, Qi,Li, Jian-Xin
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supporting information; experimental part
p. 5928 - 5930
(2012/07/27)
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- 3,6-DISUBSTITUTED XANTHYLIUM SALTS
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This invention pertains generally to processes, uses, methods and materials utilising particular xanthylium compounds, including compounds of formula (I) and (II), as further defined herein. These compounds are useful as drugs, for example, in the treatment of tauopathies, such as Alzheimer's disease.
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Page/Page column 76
(2010/07/02)
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- Water-improved heterogeneous transfer hydrogenation using methanol as hydrogen donor over Pd-based catalyst
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The heterogeneous catalytic transfer hydrogenation (CTH) of styrene and nitrobenzene over Pd-based catalyst using methanol as hydrogen donor was investigated in a fixed-bed reactor. With the increase of the molar ratio of water to methanol from 0 to 1, the conversions of styrene and nitrobenzene are increased from 26.3% and 7.1% to 100% and 31.9%, respectively, and the selectivity of aniline is increased from 22.0 to 94.5 mol%. The presence of water improves the hydrogen transfer from methanol to styrene or nitrobenzene through the quick reaction of water with formaldehyde, formed from the dehydrogenation of methanol, into formic acid, which is an excellent hydrogen donor for the CTH of unsaturated organics. In the presence of water, methanol is a better hydrogen donor than isopropanol, n-propanol and ethanol, because water cannot easily react with acetone, propionaldehyde, and acetaldehyde formed from isopropanol, n-propanol, and ethanol, respectively. Additionally, the hydrogen atom utilization of the methanol donor in the presence of water is higher than the other donors, hydrogen atom in a part of water can also be utilized for the reduction of unsaturated organics.
- Xiang, Yizhi,Li, Xiaonian,Lu, Chunshan,Ma, Lei,Zhang, Qunfeng
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scheme or table
p. 289 - 294
(2010/11/18)
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- Hydride-donor abilities of 1,4-dihydropyridines: A comparison with π nucleophiles and borohydride anions
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(Chemical Equation Presented) How are dihydropyridines like indoles? Both groups of compounds have similar nucleophilicity parameters N and are therefore suitable substrates for iminium-catalyzed reactions of α,β- unsaturated aldehydes. The N parameters of 1,4-dihydropyridines were derived from the rates of hydride transfer reactions to benzhydrylium ions (see scheme).
- Richter, Dorothea,Mayr, Herbert
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supporting information; experimental part
p. 1958 - 1961
(2009/07/25)
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- An efficient organocatalyzed multicomponent synthesis of diarylmethanes via Mannich type Friedel-Crafts reaction
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We have developed an efficient organocatalyzed, multicomponent synthesis of diarylmethane derivatives from tertiary aromatic amines, formaldehyde and 2-naphthols via Mannich type Friedel-Crafts reaction. Several organocatalysts such as (-)-chinchonidine, l-proline, l-thiaproline, and l-pipecolonic acid have been screened for the reaction but the best results were obtained with l-proline. In this Mannich type Friedel-Crafts alkylation, tertiary aromatic amines react with formaldehyde-proline adduct to generate 1-(4-(dimethylamino)benzyl)pyrrolidinium-2-carboxylate intermediate, which undergoes nucleophilic addition to give substituted diarylmethanes in excellent yields.
- Kumar, Atul,Kumar, Mukesh,Gupta, Maneesh Kumar
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experimental part
p. 7024 - 7027
(2010/02/28)
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- A novel multi-component reaction of indole, formaldehyde, and tertiary aromatic amines
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A novel multi-component reaction of indoles, formaldehydes, and tertiary aromatic amines is described for the synthesis of dialkylaminoarylated indoles using silica-supported perchloric acid (HClO4-SiO2) as an inexpensive and highly efficient catalyst. The key features of this multi-component reactions are operational simplicity, mild reaction conditions, regioselectivity, and recycling of catalyst.
- Kumar, Atul,Sharma, Siddharth,Maurya, Ram Awatar
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experimental part
p. 5937 - 5940
(2010/01/18)
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- Application of lanthanoid catalysts for the synthesis of Michler's hydride
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A series of lanthanoid (Ln3+) based Lewis acid catalysts were investigated as alternatives to other metal based catalysts for the formation of Michler's hydride, 4, 4′-methylenebis(N, N-dimethylaniline) (1). The lanthanoid based Lewis acid cata
- Andrews, Philip C.,Junk, Peter C.,Kemppinen, K. Peter,Konstas, Kristina,Tuck, Kellie L.
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scheme or table
p. 229 - 233
(2010/04/23)
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- Synthetic and mechanistic aspects of acid-catalyzed disproportionation of dialkyl diarylmethyl ethers: A combined experimental and theoretical study
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The disproportionation reactions of various dialkyl diarylmethyl ethers have been carried out in the presence of a catalytic amount (10 mol-%) of o-benzenedisulfonimide as a Bronsted acid catalyst; the reaction conditions were mild, and the yields of the diarylmethane target products were good. The catalyst was easily recovered and purified, ready to be used in further reactions. The theoretical study confirmed that the reaction proceeds in two steps: The formation of a carbocation from the protonated ether followed by hydride transfer. Although the hydride transfer is the rate-determining step, it is the stability of the carbocation that determines the reaction rate and therefore the yields.
- Barbero, Margherita,Bazzi, Stefano,Cadamuro, Silvano,Dughera, Stefano,Ghigo, Giovanni
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experimental part
p. 4346 - 4351
(2011/02/24)
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- An unusual Mannich type reaction of tertiary aromatic amines in aqueous micelles
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An efficient, unusual Mannich type reaction of tertiary aromatic amines, formaldehyde and 1,3-dicarbonyl compounds is described in aqueous micelles catalyzed by boric acid to afford dialkylaminoarylated 1,3-dicarbonyls. In this unusual Mannich type reacti
- Kumar, Atul,Maurya, Ram Awatar
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p. 5471 - 5474
(2008/12/21)
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- One-step conversion to tertiary amines: InBr3/Et3SiH-mediated reductive deoxygenation of tertiary amides
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We have developed a simple and practical procedure for a direct reductive conversion from a variety of tertiary amides to the corresponding tertiary amines using an InBr3/Et3SiH reducing system. This reducing system can be applied to the reduction of a secondary amide and provides a more efficient alternative to conventional methods that use aluminum and boron hydrides.
- Sakai, Norio,Fujii, Kohji,Konakahara, Takeo
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scheme or table
p. 6873 - 6875
(2009/04/07)
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- Alumina-mediated dealkylative dimerization of 4-aminobenzyl esters
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Treatment of 4-aminobenzyl esters with Al2O3 in DCM at rt afforded the dealkylative dimerized 4,4′-diamino-diphenylmethanes in satisfactory yield. The reaction may proceed via a quinone methide iminium ion intermediate, which may then undergo Michael type addition followed by retro-aldol extrusion of a formaldehyde species.
- Lai, Yu-Ying,Lin, Nai-Ti,Liu, Yi-Hung,Wang, Yu,Luh, Tien-Yau
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p. 6051 - 6055
(2008/02/07)
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- Stopped-flow kinetic investigations of one-electron transfer reactions of 4,4′-diaminodiphenylmethane and its radical cation in aqueous solution
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The oxidation of 4,4′-diaminodiphenylmethane (DADPM) by metal ion (Ce4+); oxoanions [MnO4- and Cr 2O72-], peroxides [peroxomonosulfate (PMS), peroxodisulfate (PDS) and H2O2], and halogens [Cl 2, Br2 and I2], to the radical cation DADPM?+, and further oxidation to the product monocation DADPM+ by the above mentioned oxidants has been investigated by stopped-flow technique. A probable mechanism has been proposed. The reactions follow a total second-order kinetics, first-order each with respect to the [DADPM] or [DADPM?+] and [oxidant]. In addition, the radical cation DADPM?+ oxidizes sulfite (SO32-), thiosulfate (S2O32-), dithionite (S 2O42-) and metabisulfite (S2O 52-) to regenerate the parent compound DADPM. The rate constants for these reactions have also been estimated. Reactivity for the formation of DADPM follows the decreasing order in the case of oxoanions (MnO4- > Cr2O72- > Ce(IV)) and peroxides (S2O82- > HSO 5- > H2O2) which is in agreement with the redox potentials, while the reactivity trend for halogens is found to be I2 > Br2 > Cl2 which is not in agreement with the redox potentials. The observed rate constants for electron transfer have been correlated theoretically using Marcus theory.
- Sankar,Aravindan,Anandan,Maruthamuthu
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p. 2218 - 2227
(2007/10/03)
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- Nucleophilic substitution on 4-hydroxymethylanilines under 'neutral' conditions via aza quinone methide intermediate
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Substitution reaction of 4-hydroxymethylaniline derivatives with resonance-stabilized carbon nucleophiles and an acid-labile nucleophile, including β-ketoester, 1,3-diketone, α-nitroester, and silylenolether, proceeded efficiently upon heating at 80°C in a neutral solvent system. The reaction was successfully applied to the synthesis of 4-aminophenylalanine.
- Takahashi, Hiroyasu,Kashiwa, Nobuyuki,Kobayashi, Hisayoshi,Hashimoto, Yuichi,Nagasawa, Kazuo
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p. 5751 - 5753
(2007/10/03)
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- Novel Mannich-type nucleophilic substitution reaction with tertiary aromatic amines
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A novel formaldehyde-mediated condensation reaction of N,N-dialkyl aromatic amines and resonance-stabilized carbon nucleophiles is described. A condensation reaction between N,N-dimethylaniline (4) and ethyl acetoacetate (8) in the presence of formaldehyd
- Takahashi, Hiroyasu,Kashiwa, Nobuyuki,Hashimoto, Yuichi,Nagasawa, Kazuo
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p. 2935 - 2938
(2007/10/03)
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- Friedel-Crafts reaction catalyzed by perfluorinated rare earth metals
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The Friedel-Crafts reaction of anisole with acetic anhydride can be carried out in the presence of perfluorinated rare earth metal catalyst without organic solvent. Perfluorodecalin (C10F18, cis- and trans-mixture) can be used as a fluorous phase solvent for this reaction. Whereas, the reaction of N,N-dimethylaniline with acetic anhydride did not give the corresponding Friedel-Crafts reaction product. On the other hand, the Friedel-Crafts reaction of N,N-dimethylaniline with ethyl glyoxylate was also examined in the presence of perfluorinated Lewis acids. Three products were in fact formed at the same time.
- Shi, Min,Cui, Shi-Cong
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p. 143 - 147
(2007/10/03)
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- Hypophosphorous acid-iodine: A novel reducing system. Part 2: Reduction of benzhydrols to diarylmethylene derivatives
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A mixture of hypophosphorous acid (H3PO2) and iodine in acetic acid reduces a variety of substituted benzhydrols to the corresponding methylene derivatives in very high yields. The active reducing agent is hydrogen iodide generated by reaction between iodine and hypophosphorous acid.
- Gordon, Paul E.,Fry, Albert J.
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p. 831 - 833
(2007/10/03)
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- Kinetics and mechanism of conjugate aminomethylation and aralkylation of N,N-dimethylaniline with N,N,N′,N′-tetraalkyldiaminomethane in acetic acid medium
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The aminomethylation of N,N-dimethylaniline with N,N,N′,N′-tetraalkyldiaminomethanes in the medium of 90.0-99.6% acetic acid is accompanied by formation of the bis(4-dimethylaminophenyl)-methane. The amount of the latter grows with increased proportion of water in the system and also depends on the ratio substrate-reagent. Proceeding from kinetic data a mechanism of the process was suggested and confirmed by mathematical simulation. The essence of the mechanism consists in the concept that aminomethylation and aralkylation proceed via a common intermediate. The second among these reactions is catalysed with water.
- Kachurin,Zaraiskii,Velichko,Zaraiskaya,Matvienko
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p. 1650 - 1655
(2007/10/03)
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- Oxidative coupling-type mechanism of N,N-dialkylanilines in solvent-free conditions forming crystal violet derivatives. A clay-mediated and microwave-promoted approach
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In the clay-mediated reaction of N,N-disubstituted anilines using microwave radiation as an energy source in the absence of solvent, crystal violet and derivatives, diphenylmethanes, and biphenyls were isolated along with intermediates supporting an oxidative coupling-type mechanism.
- Lopez-Cortes,Penieres-Carrillo,Ortega-Alfaro,Gutierrez-Perez,Toscano,Alvarez-Toledano
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p. 1299 - 1304
(2007/10/03)
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