101-61-1Relevant academic research and scientific papers
Polyethylene Glycol (PEG-400) as Methylene Spacer and Green Solvent for the Synthesis of Heterodiarylmethanes under Metal-Free Conditions
Kumar, Rahul,Rawat, Deepa,Adimurthy, Subbarayappa
, p. 3499 - 3507 (2020)
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.
Reduction of Carboxylic Acid Derivatives by BH4(1-) in Acidic Dimethyl Sulfoxide
Wann, Steven R.,Thorsen, Peter T.,Kreevoy, Maurice M.
, p. 2579 - 2581 (1981)
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.
Light-promoted N,N-dimethylation of amine and nitro compound with methanol catalyzed by Pd/TiO2 at room temperature
Zhang, Lina,Zhang, Yan,Deng, Youquan,Shi, Feng
, p. 14514 - 14521 (2015)
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.
Novel formaldehyde-mediated dimerization reaction of n-alkyl-1-naphthylamine derivatives under mild/neutral conditions; application to synthesis of naphthylamine-derived macrocycles
Takahashi, Hiroyasu,Hashimoto, Yuichi,Nagazawa, Kazuo
, p. 2305 - 2313 (2001)
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.
Kinetics and mechanism of the reactions of amine boranes with carbenium ions
Funke, Marcus-A.,Mayr, Herbert
, p. 1214 - 1222 (1997)
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).
Photochemical Trifluoromethylation of Some Aromatic and Heteroaromatic Compounds with Trifluoromethyl Bromide
Akiyama, Takeo,Kato, Kohji,Kajitani, Masatsugu,Sakaguchi, Yoshio,Nakamura, Junko,et al.
, p. 3531 - 3538 (1988)
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.
Photochemical Reaction of Diaryliodonium Salts with Dimethylaniline
Bi, Yubai,Neckers, Douglas C.
, p. 1139 - 1142 (1992)
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.
Scope and Mechanisms of Frustrated Lewis Pair Catalyzed Hydrogenation Reactions of Electron-Deficient C￡C Double Bonds
Morozova, Varvara,Mayer, Peter,Berionni, Guillaume
, p. 14508 - 14512 (2015)
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.
Stopped-flow Kinetic Study of the Formation and Decay of the 4,4'-(Dimethylamino)diphenylmethane Radical Cation in Aqueous Solution
Aravindan, Ponnu,Maruthamuthu, Pichai,Dharmalingam, Periasamy
, p. 2743 - 2750 (1995)
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.
Full N,N-Methylation of 4,4′-Methylenedianiline with Dimethyl Carbonate: A Feasible Access to 4,4′-Methylene bis(N,N-Dimethylaniline)
Qiu, Zegang,Wang, Kunjie,Li, Zhiqin,Li, Tao,Bai, Jinhao,Yin, Chanjuan,Ye, Xiushen,Liu, Haining
, (2018)
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.
