5683-33-0Relevant academic research and scientific papers
Method for catalyzing N-alkylation of aminopyridine
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Paragraph 0087-0091, (2021/08/07)
The invention discloses a method for catalyzing N-alkylation of aminopyridine. The method comprises the step of reacting an aminopyridine compound with an alkylation raw material in the presence of a heterogeneous catalyst to obtain an N-alkylated aminopyridine compound. The alkylation reaction has high activity and selectivity, is simple to operate and low in catalyst price, does not need other reaction steps, is beneficial to large-scale industrial production, and compared with previous reports, does not need to use a large amount of noble metals, can be continuously carried out, and does not use other expensive organic raw materials or reducing agents in the process. Generation of a large amount of organic waste liquid and solid waste is avoided, and collection operation of process products is simple.
Ni-Catalyzed Aryl Sulfide Synthesis through an Aryl Exchange Reaction
Isshiki, Ryota,Kurosawa, Miki B.,Muto, Kei,Yamaguchi, Junichiro
, p. 10333 - 10340 (2021/07/21)
A Ni-catalyzed aryl sulfide synthesis through an aryl exchange reaction between aryl sulfides and a variety of aryl electrophiles was developed. By using 2-pyridyl sulfide as a sulfide donor, this reaction achieved the synthesis of aryl sulfides without using odorous and toxic thiols. The use of a Ni/dcypt catalyst capable of cleaving and forming aryl-S bonds was important for the aryl exchange reaction between 2-pyridyl sulfides and aryl electrophiles, which include aromatic esters, arenol derivatives, and aryl halides. Mechanistic studies revealed that Ni/dcypt can simultaneously undergo oxidative additions of aryl sulfides and aromatic esters, followed by ligand exchange between the generated aryl-Ni-SR and aryl-Ni-OAr species to furnish aryl exchanged compounds.
Trialkylammonium salt degradation: Implications for methylation and cross-coupling
Assante, Michele,Baillie, Sharon E.,Juba, Vanessa,Leach, Andrew G.,McKinney, David,Reid, Marc,Washington, Jack B.,Yan, Chunhui
, p. 6949 - 6963 (2021/06/02)
Trialkylammonium (most notably N,N,N-trimethylanilinium) salts are known to display dual reactivity through both the aryl group and the N-methyl groups. These salts have thus been widely applied in cross-coupling, aryl etherification, fluorine radiolabelling, phase-transfer catalysis, supramolecular recognition, polymer design, and (more recently) methylation. However, their application as electrophilic methylating reagents remains somewhat underexplored, and an understanding of their arylation versus methylation reactivities is lacking. This study presents a mechanistic degradation analysis of N,N,N-trimethylanilinium salts and highlights the implications for synthetic applications of this important class of salts. Kinetic degradation studies, in both solid and solution phases, have delivered insights into the physical and chemical parameters affecting anilinium salt stability. 1H NMR kinetic analysis of salt degradation has evidenced thermal degradation to methyl iodide and the parent aniline, consistent with a closed-shell SN2-centred degradative pathway, and methyl iodide being the key reactive species in applied methylation procedures. Furthermore, the effect of halide and non-nucleophilic counterions on salt degradation has been investigated, along with deuterium isotope and solvent effects. New mechanistic insights have enabled the investigation of the use of trimethylanilinium salts in O-methylation and in improved cross-coupling strategies. Finally, detailed computational studies have helped highlight limitations in the current state-of-the-art of solvation modelling of reaction in which the bulk medium undergoes experimentally observable changes over the reaction timecourse. This journal is
Nickel-Catalyzed Amination of Aryl Chlorides with Amides
Li, Jinpeng,Huang, Changyu,Wen, Daheng,Zheng, Qingshu,Tu, Bo,Tu, Tao
supporting information, p. 687 - 691 (2021/01/09)
A nickel-catalyzed amination of aryl chlorides with diverse amides via C-N bond cleavage has been realized under mild conditions. A broad substrate scope with excellent functional group tolerance at a low catalyst loading makes the protocol powerful for synthesizing various aromatic amines. The aryl chlorides could selectively couple to the amino fragments rather than the carbonyl moieties of amides. Our protocol complements the conventional amination of aryl chlorides and expands the usage of inactive amides.
A Novel One-Pot Synthesis of N,N-Dimethylaminopyridines by Diazotization of Aminopyridines in Dimethylformamide in the Presence of Trifluoromethanesulfonic Acid
Filimonov, V. D.,Krasnokutskaya, E. A.,Potapova, M. I.,Sanzhiev, A. N.
, p. 1023 - 1028 (2020/07/25)
Abstract: Diazotization of aminopyridines in the presence of trifluoromethanesulfonic acid gives the corresponding pyridinyl trifluoromethanesulfonates instead of expected diazonium salts. Pyridinyl trifluoromethanesulfonates can be converted to N,N-dimethylaminopyridines on heating in dimethylformamide via replacement of the trifluoromethanesulfonyloxy group. The reaction is accelerated under microwave irradiation. A novel one-pot procedure has been proposed for the synthesis of 2- and 4-(dimethylamino)pyridines from commercially available aminopyridines. The procedure provides high yields of the target products, and it can be regarded as an alternative to the known methods of synthesis of N,N-dimethylpyridin-4-amine (DMAP) widely used as base catalyst in organic synthesis.
Amination of Aromatic Halides and Exploration of the Reactivity Sequence of Aromatic Halides
Yang, Chu,Zhang, Feng,Deng, Guo-Jun,Gong, Hang
, p. 181 - 190 (2019/01/10)
A base-promoted amination of aromatic halides has been developed using a limited amount of dimethylformamide (DMF) or amine as an amino source. Various aryl halides, including F, Cl, Br, and I, have been successfully aminated in good to excellent yields. Although the amination of aromatic halides with amines or DMF is usually considered as an aromatic nucleophilic substitution (SNAr) process, and the reactivity of an aromatic halide is F > Cl > Br > I, the reactivity of aromatic halides in this system was found to be I > Br a‰ F > Cl. This protocol also showed a good regioselectivity for multihalogenated aromatics. This protocol is valuable for industrial application due to the simplicity of operation, the unrestricted availability of amino sources and aromatic halides, transition metal-free conditions, no requirement for solvent, and scalability.
Iron-catalyzed protodehalogenation of alkyl and aryl halides using hydrosilanes
Pilli, Ramadevi,Balakrishnan, Venkadesh,Chandrasekaran, Revathi,Rasappan, Ramesh
supporting information, p. 1749 - 1753 (2019/02/20)
A simple and efficient iron-catalyzed protodehalogenation of alkyl and aryl halides using phenylhydrosilane is disclosed. The reaction utilizes FeCl3 without the requirement of ligands. Unactivated alkyl and aryl halides were successfully reduced in good yields; sterically hindered tertiary halides were also reduced including the less reactive chlorides. The scalability of this methodology was demonstrated by a gram-scale synthesis with a catalyst loading as low as 0.5 mol%. Notably, disproportionation of phenylsilane leads to diphenylsilane that further reduces the halides. Preliminary mechanistic studies revealed a non-radical pathway and the source of hydrogen is PhSiH3via deuterium labeling studies. Our methodology represents simplicity and provides a good alternative to typical tin, aluminum and boron hydride reagents.
Iron-Catalyzed Selective N-Methylation and N-Formylation of Amines with CO2
Li, Wen-Duo,Zhu, Dao-Yong,Li, Gang,Chen, Jie,Xia, Ji-Bao
supporting information, p. 5098 - 5104 (2019/11/03)
We herein describe an efficient iron-catalyzed selective N-methylation and N-formylation of amines with CO2 and silane using mono-phosphine as ligand. With commercially available [CpFe(CO)2]2 as catalyst, Fe-catalyzed methylation of amines was achieved with triphenylphosphine as a ligand. Using tributylphosphine as a ligand, Fe-catalyzed formylation of amines was realized at a lower temperature. The method was successfully applied in the late-stage methylation and formylation of drug molecules containing amine moiety. (Figure presented.).
UiO-type metal-organic frameworks with NHC or metal-NHC functionalities for: N-methylation using CO2 as the carbon source
Zhang, Xu,Jiang, Yilin,Fei, Honghan
supporting information, p. 11928 - 11931 (2019/10/11)
We demonstrate the first metal-organic framework (MOF) that catalyzes N-methylation of amines using 1 atm CO2 and phenylsilane under ambient conditions. Compared with its homogeneous analog, the incorporation of N-heterocyclic carbene (NHC) into the MOF provides more efficient catalysis with improved reaction kinetics, turnover numbers and recyclability. Moreover, the metalated NHC functionalized MOF achieves direct N-methylation of amines bearing carboxylate moieties, which are common building blocks in pharmaceutical chemistry.
DBU-Catalyzed Selective N-Methylation and N-Formylation of Amines with CO2 and Polymethylhydrosiloxane
Li, Gang,Chen, Jie,Zhu, Dao-Yong,Chen, Ye,Xia, Ji-Bao
supporting information, p. 2364 - 2369 (2018/05/07)
We describe herein an efficient organocatalytic system for the selective N-methylation and N-formylation of amines with carbon dioxide (CO2) as a sustainable C1 feedstock and polymethylhydrosiloxane (PMHS) as a cost-effectvie reducing reagent. High-yielding N-methylation products are obtained with low catalyst loading (1%) of DBU. Selective N-formylation of amines is achieved using the same catalytic system at a lower reaction temperature. (Figure presented.).
