2388-50-3Relevant academic research and scientific papers
ALKYLATION OF THE SULFUR- AND NITROGEN-CONTAINING COMPOUNDS ANALOGOUS TO THIAZOLINE SYSTEMS.
Ohara,Akiba,Inamoto
, p. 1508 - 1513 (1983)
Work on alylation was extended to compounds containing both sulfur and nitrogen atoms analogous to thiazoline systems, in order to obtain information on the relation between the structure of the compound and the alkylated position. Possibility of intramolecular interaction between sulfonio and amino groups is discussed based on their NMR data.
Co-condensation reactions of substituted aromatic compounds with lithium atoms at 77 K
Dunne, John P.,Bockmeyer, Matthias,Tacke, Matthias
, p. 458 - 466 (2003)
Lithium atoms were co-condensed with +I-substituted benzene derivatives like trimethyl(phenyl)silane and tert-butylbenzene in the presence of THF at 77 K, which resulted in C-H bond activation, to produce the aryllithium compound as well as the coupling o
Generation of Aryl and Heteroaryl Magnesium Reagents in Toluene by Br/Mg or Cl/Mg Exchange
Ziegler, Dorothée S.,Karaghiosoff, Konstantin,Knochel, Paul
supporting information, p. 6701 - 6704 (2018/05/05)
The alkylmagnesium alkoxide sBuMgOR?LiOR (R=2-ethylhexyl), which was prepared as a 1.5 m solution in toluene, undergoes very fast Br/Mg exchange with aryl and heteroaryl bromides, producing aryl and heteroaryl magnesium alkoxides (ArMgOR?LiOR) in toluene. These Grignard reagents react with a broad range of electrophiles, including aldehydes, ketones, allyl bromides, acyl chlorides, epoxides, and aziridines, in good yields. Remarkably, the related reagent sBu2Mg?2 LiOR (R=2-ethylhexyl) undergoes Cl/Mg exchange with various electron-rich aryl chlorides in toluene, producing diorganomagnesium species of type Ar2Mg?2 LiOR, which react well with aldehydes and allyl bromides.
Preparation method by using amine and imine nitrogen methylation and application thereof
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Paragraph 0067; 0068; 0069; 0070; 0071; 0072, (2017/08/10)
The invention discloses a preparation method by using amine and imine nitrogen methylation and application thereof. The preparation method comprises the following steps: A, adding an active carbon loaded platinum catalyst into a Schlenk tube, and after vacuumizing to replace argon, adding a solvent; B, under protection of argon, separately adding phenylsilane, an initial raw material and formic acid; C, stirring the whole reaction system at a certain temperature to react; and D, after reaction, adding ethyl acetate into the system to dilute, stopping the reaction by using a sodium hydroxide aqueous solution, performing extraction with ethyl acetate, separating out an organic phase, drying and filtering the organic phase, and performing rotatable evaporation to remove the solvent. Column chromatography is performed on residues by using ethyl acetate/petroleum ether mixed solvent to obtain a target product, wherein the ethyl acetate and petroleum ether are different in proportion. According to the application of the method in isotope labeled drug synthesis, the dosage of a catalyst is extremely low, the cost is quite low, and the method is suitable for large-scaled production, can be suitable for amine and imine with different substituents, and suitable for realizing methylation conveniently on nitrogen atoms in a natural product structure to prepare drug molecules.
Selective formylation and methylation of amines using carbon dioxide and hydrosilane catalyzed by alkali-Metal carbonates
Fang, Chi,Lu, Chunlei,Liu, Muhua,Zhu, Yiling,Fu, Yao,Lin, Bo-Lin
, p. 7876 - 7881 (2018/05/23)
The formylation and methylation of amines with carbon dioxide and hydrosilanes are emerging yet important types of transformations for CO2. Catalytic methods effective for both reactions with wide substrate scopes are rare because of the difficulty in controlling the selectivity. Herein, we report that simple and readily available inorganic bases alkali-metal carbonates, especially cesium carbonatecatalyze both the formylation and methylation reactions efficiently under mild conditions. The selectivity can be conveniently controlled by varying the reaction temperature and silane. A “cesium effect” on both reactions was observed by comparing the catalytic activity of various alkali-metal carbonates. Combined experimental and computational studies suggested the following reaction mechanism: (i) activation of Si?H by Cs2CO3, (ii) insertion of CO2 into Si?H, (iii) formylation of amines by silyl formate, and (iv) reduction of formamides to methylamines.
Methylation of aromatic amines and imines using formic acid over a heterogeneous Pt/C catalyst
Zhu, Lei,Wang, Lian-Sheng,Li, Bojie,Li, Wei,Fu, Boqiao
, p. 6172 - 6176 (2016/08/19)
We describe here a commercially available Pt/C catalyst capable of catalyzing the methylation of anilines and aromatic imines with formic acid in the presence of a hydrosilane reductant. Both primary aniline and secondary aniline can be methylated. The advantage of this newly described method includes operational simplicity, high TON, ready availability of the catalyst, and also good functional group compatibility.
N-heterocyclic carbene copper(i) catalysed N-methylation of amines using CO2
Santoro, Orlando,Lazreg, Fama,Minenkov, Yury,Cavallo, Luigi,Cazin, Catherine S. J.
, p. 18138 - 18144 (2015/10/28)
The N-methylation of amines using CO2 and PhSiH3 as source of CH3 was efficiently performed using a N-heterocyclic carbene copper(i) complex. The methodology was found compatible with aromatic and aliphatic primary and secondary amines. Synthetic and computational studies have been carried out to support the proposed reaction mechanism for this transformation.
Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids
Fu, Ming-Chen,Shang, Rui,Cheng, Wan-Min,Fu, Yao
supporting information, p. 9042 - 9046 (2015/08/03)
A boron-based catalyst was found to catalyze the straightforward alkylation of amines with readily available carboxylic acids in the presence of silane as the reducing agent. Various types of primary and secondary amines can be smoothly alkylated with good selectivity and good functional-group compatibility. This metal-free amine alkylation was successfully applied to the synthesis of three commercial medicinal compounds, Butenafine, Cinacalcet. and Piribedil, in a one-pot manner without using any metal catalysts.
Mono-N-methylation of functionalized anilines with alkyl methyl carbonates over NaY faujasites. 4. Kinetics and selectivity
Selva, Maurizio,Tundo, Pietro,Foccardi, Tommaso
, p. 2476 - 2485 (2007/10/03)
(Chemical Equation Presented) In the presence of NaY faujasite as the catalyst, the reaction of bifunctional anilines (1-4: XC6H 4-NH2; X = OH, CO2H, CH2OH, and CONH2) with methyl alkyl carbonates [MeOCO2R′: R′ = Me or MeO(CH2)2O(CH2)2] proceeds with a very high mono-N-methyl selectivity (XC6H 4NHMe up to 99%), and chemoselectivity as well, with other nucleophilic functions (OH, CO2H, CH2OH, CONH2) fully preserved from alkylation and/or transesterification reactions. Aromatic substituents, however, modify the relative reactivity of amines 1-4: good evidence suggests that, not only steric and electronic effects, but, importantly, direct acid-base interactions between substituents and the catalyst are involved. Weakly acidic groups (OH, CH2OH, CONH2, pKa ≥ 10) may help the reaction, while aminobenzoic acids (pK a of 4-5) are the least reactive substrates. The solvent polarity also affects the reaction, which is faster in xylene than in the more polar diglyme. The mono-N-methyl selectivity is explained by the adsorption pattern of reagents within the zeolite pores: a BAl2 displacement of the amine on methyl alkyl carbonate should occur aided by the geometric features of the NaY supercavities. Different factors account for the reaction chemoselectivity. Evidence proves that the polarizability of the two nucleophilic terms (NH 2 and X groups) of anilines is relevant, although adsorption and confinement phenomena of reagents promoted by the zeolite should also be considered.
Metallation reactions XXVII. Metallation of (methylthio)anilines
Cabiddu,Cabiddu,Cadoni,Cannas,De Montis,Fattuoni,Melis
, p. 263 - 275 (2007/10/03)
The metallation reactions of (methylthio)anilines with organolithium reagents and with the butyllithium-potassium tert-butoxide superbasic mixture are here described. The results show that the para isomer when treated with butyllithium gave a mixture of p
