2388-51-4Relevant academic research and scientific papers
Methylthiolation for Electron-Rich Heteroarenes with DMSO-TsCl
Zhang, Lei-Yang,Wu, Yue-Hua,Wang, Nai-Xing,Gao, Xue-Wang,Yan, Zhan,Xu, Bao-Cai,Liu, Ning,Wang, Bo-Zhou,Xing, Yalan
supporting information, p. 1446 - 1451 (2021/02/26)
DMSO-TsCl has been developed for direct methylthiolation of various electron-rich heteroarenes (more than 40 examples) with high regioselectivity in moderate to excellent yields (up to 96 %). Especially, pyrroles, furans, and thiophenes can be efficiently mono-methylthiolated. This practical method features scalable, metal-free, mild conditions and is compatible with air and moisture. Several applications of methylthiolated products were demonstrated for the first time. Based on controlled experimental results, a plausible mechanism was proposed with two key intermediates involved in the mechanism being detected by HRMS.
Photocatalytic Water-Splitting Coupled with Alkanol Oxidation for Selective N-alkylation Reactions over Carbon Nitride
Xu, Yangsen,Zhang, Zhaofei,Qiu, Chuntian,Chen, Shaoqin,Ling, Xiang,Su, Chenliang
, p. 582 - 589 (2020/12/09)
Photocatalytic water splitting technology (PWST) enables the direct use of water as appealing “liquid hydrogen source” for transfer hydrogenation reactions. Currently, the development of PWST-based transfer hydrogenations is still in an embryonic stage. Previous reports generally centered on the rational utilization of the in situ generated H-source (electrons) for hydrogenations, in which photogenerated holes were quenched by sacrificial reagents. Herein, the fully-utilization of the liquid H-source and holes during water splitting is presented for photo-reductive N-alkylation of nitro-aromatic compounds. In this integrate system, H-species in situ generated from water splitting were designed for nitroarenes reduction to produce amines, while alkanols were oxidized by holes for cascade alkylating of anilines as well as the generated secondary amines. More than 50 examples achieved with a broad range scope validate the universal applicability of this mild and sustainable coupling approach. The synthetic utility of this protocol was further demonstrated by the synthesis of existing pharmaceuticals via selective N-alkylation of amines. This strategy based on the sustainable water splitting technology highlights a significant and promising route for selective synthesis of valuable N-alkylated fine chemicals and pharmaceuticals from nitroarenes and amines with water and alkanols.
Alcohol promoted N -methylation of anilines with CO2/H2over a cobalt catalyst under mild conditions
Han, Buxing,Ke, Zhengang,Li, Ruipeng,Liu, Zhimin,Tang, Minhao,Wang, Huan,Zeng, Wei,Zhao, Yanfei
, p. 9147 - 9153 (2021/11/30)
N-Methylation of amines with CO2/H2 to N-methylamines over non-noble metal catalysts is very interesting but remains challenging. Herein, we present an alcohol (e.g., ethanol) promoted strategy for the N-methylation of anilines with CO2/H2 with high efficiency under mild conditions (e.g., 125 °C), which is achieved over a cobalt catalytic system composed of Co(OAc)2·4H2O, triphos and Sn(OTf)2. This catalytic system has a broad substrate scope and is tolerant toward a wide range of anilines and N-methyl anilines, and a series of N,N-dimethyl anilines were obtained in high yields. Mechanism investigation indicates that the alcohol solvent shifts the equilibrium of CO2 hydrogenation by forming an alkyl formate, which further reacts with the amine to produce N-formamide, and Sn(OTf)2 promotes the deoxygenative hydrogenation of N-formamides to afford N-methylamines. This is the first example of the N-methylation of amines with CO2/H2 over a cobalt catalytic system, which shows comparable performance to the reported Ru catalysts and may have promising applications.
Electrochemical and direct C-H methylthiolation of electron-rich aromatics
Wu, Yaxing,Ding, Hongliang,Zhao, Ming,Ni, Zhong-Hai,Cao, Jing-Pei
, p. 4906 - 4911 (2020/08/25)
The electrochemical-induced C-H methylthiolation of electron-rich aromatics has been accomplished via a three component cross-coupling strategy. Potassium thiocyanate (KSCN) as both the supporting electrolyte and sulfur source and methanol as the methylation reagent are used. This protocol is versatile for various (hetero)aromatic compounds such as aniline, anisole and indole. The reaction proceeds under mild conditions without any metal catalyst, exogenous oxidant and highly toxic sulfur reagent. Importantly, such an electrochemical-induced methylthiolated reaction could be easily scaled up with good efficiency.
Expedient Synthesis of N-Methyl- and N-Alkylamines by Reductive Amination using Reusable Cobalt Oxide Nanoparticles
Senthamarai, Thirusangumurugan,Murugesan, Kathiravan,Natte, Kishore,Kalevaru, Narayana V.,Neumann, Helfried,Kamer, Paul C. J.,Jagadeesh, Rajenahally V.
, p. 1235 - 1240 (2018/02/09)
N-Methyl- and N-alkylamines represent important fine and bulk chemicals that are extensively used in both academic research and industrial production. Notably, these structural motifs are found in a large number of life-science molecules and play vital roles in regulating their activities. Therefore, the development of convenient and cost-effective methods for the synthesis and functionalization of amines by using earth-abundant metal-based catalysts is of scientific interest. In this regard, herein we report an expedient reductive amination process for the selective synthesis of N-methylated and N-alkylated amines by using nitrogen-doped, graphene-activated nanoscale Co3O4-based catalysts. Starting from inexpensive and easily accessible nitroarenes or amines and aqueous formaldehyde or aldehydes in the presence of formic acid, this cost-efficient reductive amination protocol allows the synthesis of various N-methyl- and N-alkylamines, amino acid derivatives, and existing drug molecules.
Efficient and Selective N-Methylation of Nitroarenes under Mild Reaction Conditions
Pedrajas, Elena,Sorribes, Iván,Guillamón, Eva,Junge, Kathrin,Beller, Matthias,Llusar, Rosa
, p. 13205 - 13212 (2017/09/12)
Herein, we report a straightforward protocol for the preparation of N,N-dimethylated amines from readily available nitro starting materials using formic acid as a renewable C1 source and silanes as reducing agents. This tandem process is efficiently accomplished in the presence of a cubane-type Mo3PtS4 catalyst. For the preparation of the novel [Mo3Pt(PPh3)S4Cl3(dmen)3]+ (3+) (dmen: N,N′-dimethylethylenediamine) compound we have followed a [3+1] building block strategy starting from the trinuclear [Mo3S4Cl3(dmen)3]+ (1+) and Pt(PPh3)4 (2) complexes. The heterobimetallic 3+ cation preserves the main structural features of its 1+ cluster precursor. Interestingly, this catalytic protocol operates at room temperature with high chemoselectivity when the 3+ catalyst co-exists with its trinuclear 1+ precursor. N-heterocyclic arenes, double bonds, ketones, cyanides and ester functional groups are well retained after N-methylation of the corresponding functionalized nitroarenes. In addition, benzylic-type as well as aliphatic nitro compounds can also be methylated following this protocol.
Palladium-Catalyzed ipso-Borylation of Aryl Sulfides with Diborons
Bhanuchandra,Baralle, Alexandre,Otsuka, Shinya,Nogi, Keisuke,Yorimitsu, Hideki,Osuka, Atsuhiro
supporting information, p. 2966 - 2969 (2016/07/06)
A catalytic Miyaura-type ipso-borylation of aryl sulfides with diboron reagents has been achieved, providing arylboronate esters of synthetic use. The key conditions to transform inherently reluctant C-S bonds into C-B bonds include a palladium-NHC (N-heterocyclic carbene) precatalyst, bis(pinacolato)diboron, and lithium hexamethyldisilazide. This protocol is applicable to a reasonable range of aryl alkyl sulfides. Twofold borylation was observed in the reaction of diphenyl sulfide.
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.
General catalytic methylation of amines with formic acid under mild reaction conditions
Sorribes, Ivan,Junge, Kathrin,Beller, Matthias
supporting information, p. 7879 - 7883 (2014/07/07)
A general catalytic protocol for the methylation of amines has been developed applying, for the first time, formic acid as the C1 building block and silanes as reducing agents. A broad range of aromatic and aliphatic, both primary and secondary, amines has been converted to the corresponding tertiary amines including [N-13C]-labelled drugs in good to excellent yields under mild conditions. Methylation made easy: A general catalytic protocol for the methylation of amines has been developed applying, for the first time, formic acid as the C1 building block and silanes as reducing agents. A broad range of aromatic and aliphatic, both primary and secondary, amines has been converted to the corresponding tertiary amines, including [N-13C]-labelled drugs, in good to excellent yields at mild conditions (see scheme; dppp=(1,3-bis(diphenylphosphino)propane)).
A general method for N-methylation of amines and nitro compounds with dimethylsulfoxide
Jiang, Xue,Wang, Chao,Wei, Yawen,Xue, Dong,Liu, Zhaotie,Xiao, Jianliang
supporting information, p. 58 - 63 (2014/01/17)
DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for amine methylation. The protocol also allows the one-pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst. Not just a solvent: DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for amine methylation. The protocol also allows the one-pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst. Copyright
