- Additive-free selective methylation of secondary amines with formic acid over a Pd/In2O3 catalyst
-
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
-
-
- Utilization of renewable formic acid from lignocellulosic biomass for the selective hydrogenation and/or N-methylation
-
Lignocellulosic biomass is one of the most abundant renewable sources in nature. Herein, we have developed the utilization of renewable formic acid from lignocellulosic biomass as a hydrogen source and a carbon source for the selective hydrogenation and further N-methylation of various quinolines and the derivatives, various indoles under mild conditions in high efficiencies. N-methylation of various anilines is also developed. Mechanistic studies indicate that the hydrogenation occurs via a transfer hydrogenation pathway.
- Zhou, Chao-Zheng,Zhao, Yu-Rou,Tan, Fang-Fang,Guo, Yan-Jun,Li, Yang
-
p. 4724 - 4728
(2021/09/06)
-
- Trialkylammonium salt degradation: Implications for methylation and cross-coupling
-
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
- 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)
-
- Method for realizing N-alkylation by using alcohols as carbon source under photocatalysis
-
The invention discloses a method for realizing N-alkylation by using alcohols as a carbon source under photocatalysis, and belongs to the technical field of catalytic synthesis. Alcohol, a substrate raw material and a catalyst are placed in a reaction device, ultraviolet and/or visible light irradiation is carried out in an inert atmosphere, after the irradiation is finished, solid-liquid separation is carried out to remove the catalyst, and an N-alkylation product can be obtained through extraction, distillation and purification, wherein the substrate raw material comprises any one of an amine compound, an aromatic nitro compound or an aromatic nitrile compound, the alcohol comprises any one or more of soluble primary alcohols, and the catalyst is metal oxide/titanium dioxide or metal sulfide/titanium dioxide. The method is simple and easy to operate, can be used for efficient photocatalysis one-pot multi-step hydrogenation N-alkylation reaction, and is mild in reaction condition, high in chemical selectivity of N-alkylamine, good in catalyst stability and easy to recycle.
- -
-
Paragraph 0048-0056; 0058
(2021/03/13)
-
- Photocatalytic Water-Splitting Coupled with Alkanol Oxidation for Selective N-alkylation Reactions over Carbon Nitride
-
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.
- Xu, Yangsen,Zhang, Zhaofei,Qiu, Chuntian,Chen, Shaoqin,Ling, Xiang,Su, Chenliang
-
p. 582 - 589
(2020/12/09)
-
- Preparation method of N-alkylated derivative of primary amine compound
-
The invention relates to a preparation method of an N-alkylated derivative of a primary amine compound. The method comprises the following steps: uniformly mixing a primary amine compound, an alcohol compound and a catalyst in a reactor, and heating to react for a period of time to generate an N-alkylated substituted tertiary amine compound; wherein the catalyst is a copper-cobalt bimetallic catalyst, and the carrier of the catalyst is Al2O3. According to the method, alcohol is adopted as an alkylating reagent and is low in price and easy to obtain, a byproduct is water, no pollution is caused to the environment, and the overall reaction atom economy is high; the catalyst is simple in preparation method, low in cost, high in reaction activity and good in structural stability; meanwhile, by using the copper-cobalt bimetallic catalyst, the use of strong base additives can be avoided, and the requirement on reaction equipment is low; and the reaction post-treatment is convenient, and the catalyst can be recycled and is environment-friendly.
- -
-
Paragraph 0021; 0045
(2021/07/09)
-
- Additive-freeN-methylation of amines with methanol over supported iridium catalyst
-
An efficient and versatile zinc oxide-supported iridium (Ir/ZnO) catalyst was developed to catalyze the additive-freeN-methylation of amines with methanol. Mechanistic studies suggested that the high catalytic reactivity is rooted in the small sizes (1.4 nm) of Ir nanoparticles and the high ratio (93%) of oxidized iridium species (IrOx, Ir3+and Ir4+) on the catalyst. Moreover, the delicate cooperation between the IrOxand ZnO support also promoted its high reactivity. The selectivity of this catalyticN-methylation was controllable between dimethylation and monomethylation by carefully tuning the catalyst loading and reaction solvent. Specifically, neat methanol with high catalyst loading (2 mol% Ir) favored the formation ofN,N-dimethylated amine, while the mesitylene/methanol mixture with low catalyst loading (0.5 mol% Ir) was prone to producing mono-N-methylated amines. An environmentally benign continuous flow system with a recycled mode was also developed for the efficient production ofN-methylated amines. With optimal flow rates and amine concentrations, a variety ofN-methylamines were produced with good to excellent yields in this Ir/ZnO-based flow system, providing a starting point for the clean and efficient production ofN-methylamines with this cost-effective chemical process.
- Liu, Xiang,Loh, Teck-Peng,Qiang, Wenwen,Wang, Jing,Ye, Sen,Zhu, Longfei
-
p. 3364 - 3375
(2021/06/06)
-
- Air-tolerant direct reductive N-methylation of amines using formic acid via simple inorganic base catalysis
-
The construction of N-methyl amine moieties is an important reaction that has found numerous applications. Development of new methylation agents that are more environmentally benign than classical agents, such as iodomethane and methyl sulfate, is still highly desirable. Herein, we report a convenient protocol for direct reductive N-methylation of amines using formic acid as the methylation agent via simple inorganic base catalysis. The present protocol operates under transition-metal-free and air-tolerant conditions. Both the catalyst, K2HPO4, and the reductant, polymethylhydrosiloxane (PMHS), are cheap and easily separable from the crude reaction product mixture. Mechanistic investigations suggest that the reaction occur through the formation of an acetal intermediate followed by the C–N bond formation.
- Huang, Yan,Deng, Wei,Lin, Bo-Lin
-
supporting information
(2019/05/29)
-
- Three-Component Aminoselenation of Arynes
-
The three-component coupling of tertiary amines, arynes, and aryl selenium bromide or diaryl diselenide as an electrophilic selenium source allowing the synthesis of 2-selanyl aniline derivatives is reported. This aminoselenation reaction of arynes installs a C-N and C-Se bond under mild conditions, and the products are formed in moderate to good yields. This reaction is compatible with various functional groups, and the preliminary studies on the mechanism of the reaction is also provided.
- Gaykar, Rahul N.,Guin, Avishek,Bhattacharjee, Subrata,Biju, Akkattu T.
-
supporting information
p. 9613 - 9617
(2019/11/28)
-
- Synergistic catalysis of Cu+/Cu0 for efficient and selective N-methylation of nitroarenes with para-formaldehyde
-
In this paper, an inexpensive heterogeneous copper nanoparticles catalyst derived from CuAl-layered double hydroxide via an in situ topotactic transformation process was developed. Cu nanoparticles with uniform size were homogeneously dispersed on amorphous Al2O3 with strong metal-support interaction. Characterization results reveals that the Cu0 and Cu+ were simultaneously formed with Cu+ species as the dominant sites on the surface during the reduction process. The resultant catalyst Cu/Al2O3 demonstrates high catalytic activity, selectivity and durability for the reductive N-methylation of easily available nitroarenes in a cost-efficient, environmentally friendly and cascade manner. A broad spectrum of nitroarenes could be efficiently N-methylated to their corresponding N,N-dimethyl amines with good compatibility of various functional groups. The protocol is also applicable for the late-stage functionalization of biologically and pharmaceutically active nitro molecules. A structure-function relationship discloses that Cu0 and Cu+ sites on the surface pronouncedly boosts the reaction efficiency in a synergistic manner, in which Cu0 could facilitate H2 production and N-methylation of anilines, while Cu+ is considerably more active and participates in the overall process of the selective N-methylation of nitroarenes. Moreover, the catalyst also showed a strong stability and could be easily separated for successive reuses without an appreciable loss in activity and selectivity.
- Dong, Xiaosu,Wang, Zhaozhan,Yuan, Youzhu,Yang, Yong
-
p. 304 - 313
(2019/07/02)
-
- Method for N-methylation reaction of nitro-compound
-
The invention discloses a method for direct N-methylation reaction by taking a nitro-compound as a raw material. The method adopts a Cu-based catalyst and polyformaldehyde and can realize the direct N-methylation reaction of the nitro-compound under mild conditions.
- -
-
Paragraph 0050-0054
(2019/01/23)
-
- Para-Selective C-H Olefination of Aniline Derivatives via Pd/S,O-Ligand Catalysis
-
Herein we report a highly para-selective C-H olefination of aniline derivatives by a Pd/S,O-ligand-based catalyst. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, including mono-, di-, and trisubstituted tertiary, secondary, and primary anilines. The S,O-ligand is responsible for the dramatic improvements in substrate scope and the high para-selectivity observed. This methodology is operationally simple, scalable, and can be performed under aerobic conditions.
- Naksomboon, Kananat,Poater, Jordi,Bickelhaupt, F. Matthias,Fernández-Ibá?ez, M. ángeles
-
supporting information
p. 6719 - 6725
(2019/05/06)
-
- Nickel(II) Tetraphenylporphyrin as an Efficient Photocatalyst Featuring Visible Light Promoted Dual Redox Activities
-
Nickel(II) tetraphenylporphyrin (NiTPP) is presented as a robust, cost-effective and efficient visible light induced photoredox catalyst. The ground state electrochemical data (CV) and electronic absorption (UV-Vis) spectra reveal the excited state redox potentials for [NiTPP]*/[NiTPP].? and NiTPP].+/[NiTPP]* couples as +1.17 V and ?1.57 V vs SCE respectively. The potential values represent NiTPP as a more potent photocatalyst compare to the well-explored [Ru(bpy)3]2+. The non-precious photocatalyst exhibits excited state redox reactions in dual fashions, i. e., it is capable of undergoing both oxidative as well as reductive quenching pathways. Such versatility of a photocatalyst based on first-row transition metals is very scarce. This unique phenomenon allows one to perform diverse types of redox reactions by employing a single catalyst. Two different sets of chemical reactions have been performed to represent the synthetic utility. The catalyst showed superior efficiency in both carbon-carbon and carbon-heteroatom bond-forming reactions. Thus, we believe that NiTPP is a valuable addition to the photocatalyst library and this study will lead to more practical synthetic applications of earth-abundant-metal-based photoredox catalysts. (Figure presented.).
- Mandal, Tanumoy,Das, Sanju,De Sarkar, Suman
-
supporting information
p. 3200 - 3209
(2019/05/16)
-
- Expedient Synthesis of N-Methyl- and N-Alkylamines by Reductive Amination using Reusable Cobalt Oxide Nanoparticles
-
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.
- Senthamarai, Thirusangumurugan,Murugesan, Kathiravan,Natte, Kishore,Kalevaru, Narayana V.,Neumann, Helfried,Kamer, Paul C. J.,Jagadeesh, Rajenahally V.
-
p. 1235 - 1240
(2018/02/09)
-
- Efficient and versatile catalytic systems for the n-methylation of primary amines with methanol catalyzed by n-heterocyclic carbene complexes of iridium
-
Efficient and versatile catalytic systems were developed for the N-methylation of both aliphatic and aromatic primary amines using methanol as the methylating agent. Iridium complexes bearing an Nheterocyclic carbene (NHC) ligand exhibited high catalytic performance for this type of transformation. For aliphatic amines, selective N,N-dimethylation was achieved at low temperatures (50-90 °C). For aromatic amines, selective N-monomethylation and selective N,N-dimethylation were accomplished by simply changing the reaction conditions (presence or absence of a base with an appropriate catalyst). These findings can be used to develop methods for synthesizing useful amine compounds having N-methyl or N,N-dimethyl moieties.
- Toyooka, Genki,Tuji, Akiko,Fujita, Ken-Ichi
-
p. 4617 - 4626
(2019/02/01)
-
- N-Alkylation of Aniline and Its Derivatives by Alcohols in the Presence of Copper Compounds
-
N-Alkyl- and N,N-dialkyl-substituted anilines were obtained in the reaction of aniline and its derivatives with primary and secondary alcohols in the presence of catalysts CuCl2·2H2O, CuBr2 and halomethanes as promoters.
- Bayguzina,Musina, Ch. F.,Khusnutdinov
-
p. 1652 - 1659
(2019/02/12)
-
- Synthesis of Halogenated Anilines by Treatment of N, N-Dialkylaniline N-Oxides with Thionyl Halides
-
The special reactivity of N,N-dialkylaniline N-oxides allows practical and convenient access to electron-rich aryl halides. A complementary pair of reaction protocols allow for the selective para-bromination or ortho-chlorination of N,N-dialkylanilines in up to 69% isolated yield. The generation of a diverse array of halogenated anilines is made possible by a temporary oxidation level increase of N,N-dialkylanilines to the corresponding N,N-dialkylaniline N-oxides and the excision of the resultant weak N-O bond via treatment with thionyl bromide or thionyl chloride at low temperature.
- Reed, Hayley,Paul, Tyler R.,Chain, William J.
-
p. 11359 - 11368
(2018/08/06)
-
- N-Mannich Bases of Aromatic Heterocyclic Amides: Synthesis via Copper-Catalyzed Aerobic Cross-Dehydrogenative Coupling under Ambient Conditions
-
An efficient and facile method to synthesize N-Mannich bases has been developed using an inexpensive copper(I) bromide/air catalyst system at ambient temperature. A cross-dehydrogenative coupling of N,N-dimethylarylamines occurs efficiently with aromatic heterocyclic amides (oxindoles, isatins), cyclic amides (lactams), simple amides (benzamide), as well as imides (succinimide, phthalimide) to furnish the corresponding amidated/imidated derivatives in good to excellent yields. Preliminary mechanistic and isotope-labeling studies suggest the reaction follows a radical pathway and involves an iminium ion intermediate.
- Singh, Shailendra K.,Chandna, Nisha,Jain, Nidhi
-
supporting information
p. 1322 - 1325
(2017/03/23)
-
- Preparation method by using amine and imine nitrogen methylation and application thereof
-
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.
- -
-
Paragraph 0125; 0126; 0127; 0128; 0129; 0130
(2017/08/10)
-
- N, N -Dimethylation of nitrobenzenes with CO2 and water by electrocatalysis
-
We have proposed a strategy for the synthesis of N,N-dimethylanilines from nitrobenzene and its derivatives, CO2, and water via an electrochemical reaction under ambient conditions. H+ generated from H2O was used as the hydrogen source. Pd/Co-N/carbon, in which the Pd nanoparticles were supported on Co-N/carbon, was designed and used as the electrocatalyst. It was found that the electrocatalyst was very efficient for the reaction in MeCN solution with 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Bmim]Tf2N) as the supporting electrolyte and 1-amino-methylphosphonic acid (AMPA) as the thermal co-catalyst. A series of control experiments showed that Pd/Co-N/carbon and AMPA cooperated very well in accelerating the reaction. This synthetic route has some obvious advantages, such as using CO2 and water as the reactants, ambient reaction conditions, and high yields of the desired products. This opens up a way to synthesize chemicals by the combination of an electrocatalyst and a thermal catalyst with organic compounds, CO2, and water as the reactants.
- Sun, Xiaofu,Zhu, Qinggong,Hu, Jiayin,Kang, Xinchen,Ma, Jun,Liu, Huizhen,Han, Buxing
-
p. 5669 - 5674
(2017/08/01)
-
- Efficient and Selective N-Methylation of Nitroarenes under Mild Reaction Conditions
-
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.
- Pedrajas, Elena,Sorribes, Iván,Guillamón, Eva,Junge, Kathrin,Beller, Matthias,Llusar, Rosa
-
p. 13205 - 13212
(2017/09/12)
-
- Deoxygenation of tertiary amine N-oxides under metal free condition using phenylboronic acid
-
A simple and efficient method for the deoxygenation of amine N-oxides to corresponding amines is reported using the green and economical reagent phenylboronic acid. Deoxygenation of N,N-dialkylaniline N-oxides, trialkylamine N-oxides and pyridine N-oxides were achieved in good to excellent yields. The reduction susceptible functional groups such as ketone, amide, ester and nitro groups are well tolerated with phenylboronic acid during the deoxygenation process even at high temperature. In addition, an indirect method for identification and quantification of tert-amine N-oxide is demonstrated using UV–Vis spectrometry which may be useful for drug metabolism studies.
- Gupta, Surabhi,Sureshbabu, Popuri,Singh, Adesh Kumar,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
-
supporting information
p. 909 - 913
(2017/02/15)
-
- Methylation of aromatic amines and imines using formic acid over a heterogeneous Pt/C catalyst
-
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.
- Zhu, Lei,Wang, Lian-Sheng,Li, Bojie,Li, Wei,Fu, Boqiao
-
p. 6172 - 6176
(2016/08/19)
-
- Selective formylation and methylation of amines using carbon dioxide and hydrosilane catalyzed by alkali-Metal carbonates
-
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.
- Fang, Chi,Lu, Chunlei,Liu, Muhua,Zhu, Yiling,Fu, Yao,Lin, Bo-Lin
-
p. 7876 - 7881
(2018/05/23)
-
- Boron-Catalyzed N-Alkylation of Amines using Carboxylic Acids
-
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.
- Fu, Ming-Chen,Shang, Rui,Cheng, Wan-Min,Fu, Yao
-
supporting information
p. 9042 - 9046
(2015/08/03)
-
- Convenient Reductive Methylation of Amines with Carbonates at Room Temperature
-
Methylation of amines is a fundamental and commonly used reaction in organic synthesis. Many methods are known including various reductive methylations using formaldehyde, formic acid, or carbon dioxide in the presence of reductants. However, several of these methods suffer from limited substrate scope and chemoselectivity because of the different nucleophilicities of substrates. In this respect, the combination of carbonates and hydrosilanes is a valuable methylation source in the presence of Pt-based catalysts. This highly tunable method allows for methylation of both aromatic and aliphatic amines, and chemoselective methylation of aminoalcohols and diamines. Notably, the in situ-formed catalyst can also be used for the reduction of carbonates to methanol at room temperature. Mechanistic insights on intermediates formed during the reaction pathway were obtained by using ESI mass spectrometry.
- Li, Yuehui,Sorribes, Iván,Vicent, Cristian,Junge, Kathrin,Beller, Matthias
-
p. 16759 - 16763
(2015/11/16)
-
- Azo-functionalized microporous organic polymers: Synthesis and applications in CO2 capture and conversion
-
Azo-functionalized MOPs (Azo-MOPs) were synthesized via oxidative polymerization of aromatic amines catalyzed by t-BuOCl/NaI (25 °C, 1 h, yield: >95%), which displayed an excellent coordinating ability with a Ru complex. The resulting Ru-coordinated Azo-MOPs displayed high CO2 capacity and high performances for catalyzing the methylation of amines with CO2 under low pressure (0.5 MPa).
- Yang, Zhenzhen,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Ma, Zhishuang,Ji, Guipeng,Han, Buxing,Liu, Zhimin
-
supporting information
p. 11576 - 11579
(2015/07/15)
-
- B(C6F5)3-catalyzed methylation of amines using CO2 as a C1 building block
-
B(C6F5)3 was proven to be an efficient metal-free catalyst for the methylation of amines using CO2 as a C1 building block in the presence of hydrosilanes under easy-handling conditions. A broad range of N-alkylanilines, dialkylamines and primary anilines all proceeded well under the catalytic conditions.
- Yang, Zhenzhen,Yu, Bo,Zhang, Hongye,Zhao, Yanfei,Ji, Guipeng,Ma, Zhishuang,Gao, Xiang,Liu, Zhimin
-
supporting information
p. 4189 - 4193
(2015/08/11)
-
- Fluoro-functionalized polymeric N-heterocyclic carbene-zinc complexes: Efficient catalyst for formylation and methylation of amines with CO2 as a C1-building block
-
A fluoro-functionalized polymeric N-heterocyclic carbene (NHC)-Zn complex (F-PNHC-Zn) was designed and synthesized by taking fluorous imidazolium salts as precursors through a two-step alkylation. The resultant F-PNHC-Zn was applied in catalyzing the formylation and methylation of amines using CO2 as a C1 building block in the presence of organosilane, which showed much higher activity than the corresponding non-fluorous PNHC-Zn under identical conditions. N-Methylanilines with both electron-withdrawing and electron-donating groups all could be converted to the corresponding formamides and methylamines in >90% conversion. Quantitative conversion of N-methylaniline was obtained even under very low CO2 pressure (0.05 MPa diluted by N2). Moreover, F-PNHC-Zn was highly stable and easily recyclable for these reactions. This journal is
- Yang, Zhen-Zhen,Yu, Bo,Zhang, Hongye,Zhao, Yanfei,Ji, Guipeng,Liu, Zhimin
-
p. 19613 - 19619
(2015/06/09)
-
- Light-promoted N,N-dimethylation of amine and nitro compound with methanol catalyzed by Pd/TiO2 at room temperature
-
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
-
p. 14514 - 14521
(2015/03/05)
-
- Catalytic methylation of aromatic amines with formic acid as the unique carbon and hydrogen source
-
A novel methodology is presented for the direct methylation of amines, using formic acid as a unique source of carbon and hydrogen. Based on ruthenium(II) catalysts, the formation of the N - CH3group proceeds via an efficient formylation/transfer hydrogenation pathway.
- Savourey, Solne,Lefvre, Guillaume,Berthet, Jean-Claude,Cantat, Thibault
-
supporting information
p. 14033 - 14036
(2015/02/19)
-
- Carbon Dioxide Reduction to Methylamines under Metal-Free Conditions
-
The first metal-free catalysts are reported for the methylation of amines with carbon dioxide. Proazaphosphatrane superbases prove to be highly active catalysts in the reductive functionalization of CO2, in the presence of hydroboranes. The new methodology enables the methylation of N-H bonds in a wide variety of amines, including secondary amines, with increased chemoselectivity. Organocatalysis: Proazaphosphatrane superbases prove to be highly active catalysts in the reductive functionalization of CO2, in the presence of hydroboranes. The new method makes possible the methylation of N-H bonds in a wide variety of amines, including secondary amines (see picture), with increased chemoselectivity.
- Blondiaux, Enguerrand,Pouessel, Jacky,Cantat, Thibault
-
p. 12186 - 12190
(2016/02/23)
-
- General catalytic methylation of amines with formic acid under mild reaction conditions
-
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)).
- Sorribes, Ivan,Junge, Kathrin,Beller, Matthias
-
supporting information
p. 7879 - 7883
(2014/07/07)
-
- A general method for N-methylation of amines and nitro compounds with dimethylsulfoxide
-
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
- Jiang, Xue,Wang, Chao,Wei, Yawen,Xue, Dong,Liu, Zhaotie,Xiao, Jianliang
-
supporting information
p. 58 - 63
(2014/01/17)
-
- Selective methylation of amines with carbon dioxide and H2
-
Put a label on it: Carbon dioxide with H2 is shown to be an efficient and selective methylation reagent for aromatic and aliphatic amines (see scheme; acac=acetylacetonate, triphos = 1,1,1- tris(diphenylphosphanylmethyl)ethane). A variety of functionalized amines including 13C-labelled drugs were obtained with good yields and functional-group tolerance. Copyright
- Li, Yuehui,Sorribes, Ivan,Yan, Tao,Junge, Kathrin,Beller, Matthias
-
supporting information
p. 12156 - 12160
(2013/12/04)
-
- One-pot synthesis of N,N-dimethylanilines from nitroarenes with skeletal Cu as chemoselective catalyst
-
A range of N,N-dimethylanilines were synthesized with excellent yields in one-pot by the hydrogenation and alkylation of nitroarenes with H2 and HCHO over quenched skeletal Cu catalyst, which provides a facile, economical, and environmentally benign alternative methodology for C-N bonds formation.
- Rong, Zeming,Zhang, Wenjun,Zhang, Peng,Sun, Zhuohua,Lv, Jinkun,Du, Wenqiang,Wang, Yue
-
p. 115 - 118
(2013/09/02)
-
- CO2 as a C1-building block for the catalytic methylation of amines
-
A novel catalytic reaction has been designed to utilize, for the first time, CO2 as a C1 feedstock in the synthesis of N-methylamines. Simple zinc catalysts, based on commercially available zinc salts and ligands, prove highly efficient in promoting both a 6 electron reduction of carbon dioxide and the formation of a C-N bond, using hydrosilanes and amines.
- Jacquet, Olivier,Frogneux, Xavier,Das Neves Gomes, Christophe,Cantat, Thibault
-
p. 2127 - 2131
(2013/05/21)
-
- Safe and efficient reductive methylation of primary and secondary amines using N-methylpyrrolidine zinc borohydride
-
An efficient, general procedure for reductive methylation of primary and secondary amines with 37% formaldehyde using N-methylpyrrolidine zinc borohydride (ZBHNMP) as a reducing agent gave the corresponding tertiary amines in excellent yields. The reaction was carried out in tetrahydrofuran under neutral conditions at 0-10°C. Copyright Taylor & Francis Group, LLC.
- Alinezhad, Heshmatollah,Tajbakhsh, Mahmood,Salehian, Fatemeh,Fazli, Kazem
-
scheme or table
p. 2415 - 2420
(2010/09/08)
-
- PHENOTHIAZIN DERIVATIVES FOR ANTIVIRAL TREATMENTS
-
Compounds and methods for preventing and treating viral infections are provided. In some embodiments, novel compounds broad-spectrum antiviral activity are provided. In more specific embodiments, the compounds and methods are effective against viruses such as Venezuelan Equine Encephalitis, West Nile Virus, and Hepatitis C.
- -
-
Page/Page column 18
(2008/12/04)
-
- Dichlorobis(1,4-diazabicyclo[2.2.2]octane)(tetrahydroborato)zirco- nium(IV), [Zr(BH4)2Cl2(dabco)2](ZrBDC), as a new, stable, and versatile bench top reducing agent: Reduction of imines and enamines, reductive amination of aldehydes and ketones and reductive methylation of amines
-
The reducing agent is easily prepared in an almost quantitative yield from commercially available starting materials. This compound is stable under mild aqueous acidic conditions (pH 4-6) and survives in H2O for several days without losing its reducing abilities. ZrBDC has been successfully used for the reduction of imines and enamines, reductive amination of aldehydes and ketones, and reductive methylation of amines.
- Firouzabadi, Habib,Iranpoor, Nasser,Alinezhad, Heshmatollah
-
p. 143 - 151
(2007/10/03)
-
- Activation of the aryl hydrocarbon receptor by methyl yellow and related congeners: structure-activity relationships in halogenated derivatives.
-
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the biological action of many environmental compounds. Methyl yellow (4-dimethylaminoazobenzene; MY) is a principal azo-dye, and structurally related compounds were subjected to analysis of structure-activity relationships as AhR ligands by using a yeast AhR signaling assay. The effects of halogen-substitution among 23 halogenated MYs on the AhR ligand activity can be summarized as follows: enhancement by halogen-substitution at the ortho-position (2'- and 6'-position), and reduction by substitution at the para-position (4'-position). The greatest enhancement of the ligand activity was observed in 2',6'-dichlorinated MY (13.5-fold of MY), and its AhR ligand activity was very close to that of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the present assay system. In the study of compounds structurally related to MY, benzanilide (BA) showed almost the same AhR ligand activity as azobenzene and trans-stilbene. Furthermore, 4'-chlorobenzanilide, in which the length of the molecule is similar to that of MY, enhanced the AhR ligand activity by ortho(2')-chlorine-substitution, and the AhR ligand activity of 2',4'-dichlorobenzanilide was similar to that of 2'-chloro-MY. These results suggest that the amide bond is equivalent to the -N=N- or -CH=CH- double bond for recognition as the ligand by AhR in 1,2-diphenyl-1,2-ene derivatives.
- Kato, Taka-aki,Matsuda, Tomonari,Matsui, Saburo,Mizutani, Takaharu,Saeki, Ken-ichi
-
p. 466 - 471
(2007/10/03)
-
- NUCLEOPHILIC SUBSTITUTION REACTION OF BENZYL BROMIDE WITH N,N-DIMETHYLANILINE: SIGNIFICANCE OF EQUILIBRIUM CROSS-INTERACTION CONSTANT
-
Kinetic studies on the reversible reactions of benzyl bromides with N,N-dimethylanilines were carried out for both the forward (kf) and reverse (kr) directions.The equilibrium constants, K were calculated using the ratio kf//kr and the equilibrium cross-interaction constant, ρeXY was determined.The ρeXY value was shown to represent a maximum intensity of interactions between substituents X and Y through covalent bonds within a molecule.The normalized values of ρX (ρnuc) and ρXY indicate that in the transition state the fractional development or loss of polar and resonance interactions in the benzyl system are imbalanced or non-perfectly synchronized.In the forward reaction the fractional loss of resonance interaction becomes enhanced, whereas in the reverse reaction the fractional development of resonance interaction lags behind the corresponding changes of polar interaction by ca 45percent.
- Lee, Ikchoon,Park, Yong Kyun,Huh, Chul,Lee, Hai Whang
-
p. 555 - 560
(2007/10/02)
-
- Rate-Equilibrium Relationships for Reactions of Families of Carbanion Nucleophiles with N-Benzyl-N,N-dimethylanilinium Cations and with Alkyl Chlorides, Bromides, and Iodides
-
Rates of reaction of a family of 9-methylfluorenide anions, 9-MeFl-, with 15 substituted N-benzyl-N,N-dimethylanilinium cations, GC6H4CH2N(Me)2C6H4Y+, were measured in a 0.8 M KNO3 solution of Me2SO at 25 deg C.Substitution in the benzyl moiety produced a U-shaped Hammett plot, with m-CN reacting 9- to 15-fold faster than H and p-MeO reacting 1.5- to 3-fold faster than H, depending on the basicity of the 9-RFl- ion.Broensted ΒNu values obtained by varying nucleophile basicity in the 9-MeFl- ion family were 0.28 for N-(p-methoxybenzyl)-N,N-dimethylanilinium ion, 0.33 for N-benzyl-N,N-dimethylanilinium ion, and 0.39 for N-(m-cyanobenzyl)-N,N-dimethylanilinium ion.These βNu values were unaffected by substitution in the aniline portion of the substrate.Hammett pLg values were obtained by substitution of m-Cl, p-Br, H, p-Me and p-MeO groups (Y) in the dimethylaniline leaving group; pLg values were all near 2.0 and were insensitive to the basicity of the attacking nucleophile and the substituent G in the benzyl group of the substrate. βNu values for families of 9-RFl- ions reacting with ArCH2X, n-BuX, and CNCH2X also remained constant as the leaving group, X, was changed (Cl, Br, and I) for a given substrate and when the donor atom was changed along the series C-, N-, O-, and S-.These results indicate that there is no direct relationship between the size of βNu and the extent of bond making or bond breaking in the transition state for SN2 reactions, as has been generally assumed in theoretical attempts to rationalize the effects of structural variations on rate.It is suggested that SN2 reactions occur in two stages.The size of βNu is determined in the first stage where an ion-dipole complex is formed.The rate is determined largely in the second stage where bonds are formed and cleaved and where molecular and solvent reorganization occurs.
- Bordwell, Frederick G.,Hughes, David L.
-
p. 7300 - 7309
(2007/10/02)
-
- Azo dyes derived from 3-amino pyridine in hair dye compositions
-
A composition for dyeing hair comprises in a cosmetic vehicle at least one dye compound of the formula STR1 wherein B is selected from the group consisting of STR2 and STR3 wherein R is lower alkyl containing 1-4 carbon atoms, R1 is selected from the group consisting of hydrogen, lower alkyl containing 1-4 carbon atoms, lower alkoxy containing 1-4 carbon atoms and chlorine, R2 is selected from the group consisting of hydrogen, methyl and methoxy, R4 is selected from the group consisting of hydrogen, methyl, chlorine, nitro, amino and acetylamino, R3 is hydrogen or together with R4 forms an unsaturated 6 membered ring carrying a hydroxy substituent chelated with one of the nitrogen atoms of the azo link, and STR4 where R5 is selected from the group consisting of hydrogen, -CH3, -C2 H5 and β-hydroxyethyl, and R6 is selected from the group consisting of hydrogen, --CH3, --C2 H5, β-hydroxyethyl, phenyl and -CH2 SO3 Na, With the proviso that when B is STR5 the anion X- associated with the quaternized nitrogen atom is the anion residue of a member selected from the group consisting of organic acid and mineral acid, said composition having a pH ranging from 3 to 11 and said compound being present in an amount ranging from 0.001 to 1 percent by weight of said composition.
- -
-
-