cas 611-21-2, N-METHYL-O-TOLUIDINE | Articles data

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Synthesis of N-Alkyl Anilines from Arenes via Iron-Promoted Aromatic C-H Amination
We report both an intermolecular C-H amination of arenes to access N-methylanilines and an intramolecular variant for the synthesis of tetrahydroquinolines. A newly developed, highly electrophilic aminating reagent was key for the direct synthesis of unprotected N-methylanilines from simple arenes. The reactions display a broad functional group tolerance and employ catalytic amounts of a benign iron salt under mild reaction conditions.
Falk, Eric,Gasser, Valentina C. M.,Morandi, Bill
supporting information
p. 1422 - 1426
(2021/03/08)

CO2-tuned highly selective reduction of formamides to the corresponding methylamines
We herein describe an efficient, CO2-tuned and highly selective C-O bond cleavage of N-methylated formanilides. With easy-to-handle and commercially available NaBH4 as the reductant, a variety of formanilides could be turned into the desired tertiary amines in moderate to excellent yields. The role of CO2 has been investigated in detail, and the mechanism is proposed on the basis of experiments.
Chao, Jianbin,Guo, Zhiqiang,Pang, Tengfei,Wei, Xuehong,Xi, Chanjuan,Yan, Leilei
supporting information
p. 7534 - 7538
(2021/10/12)

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.
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Paragraph 0048-0057

(2021/03/13)

Effect of the ancillary ligand in N-heterocyclic carbene iridium(III) catalyzed N-alkylation of amines with alcohols
A series of air-stable N-heterocyclic carbene (NHC) Ir(III) complexes (Ir1-6), bearing various combinations of chlorine, pyridine and NHC ligands, were assayed for the N-alkylation of amines with alcohols. It was found that Ir3, with two monodentate 1,3-bis-methyl-imidazolylidene (IMe) ligands, emerged as the most active complex. A large variety of amines and primary alcohols were efficiently converted into mono-N-alkylated amines in 53–96% yields. As a special highlight, for the challenging MeOH, selective N-monomethylation could be achieved using KOH as a base under an air atmosphere. Moreover, this catalytic system was successfully applied to the gram-scale synthesis of some valuable compounds.
Feng, Xinshu,Huang, Ming
(2021/06/21)

Efficient methylation of anilines with methanol catalysed by cyclometalated ruthenium complexes
Cyclometalated ruthenium complexes4-10allow the effective methylation of anilines with methanol to selectively giveN-methylanilines. This hydrogen autotransfer procedure proceeds under mild conditions (60 °C) in a practical manner (NaOH as base). Mechanistic investigations suggest an active homogenous ruthenium complex and β-hydride elimination of methanol as the rate determining step.
Piehl, Patrick,Amuso, Roberta,Spannenberg, Anke,Gabriele, Bartolo,Neumann, Helfried,Beller, Matthias
p. 2512 - 2517
(2021/04/22)

Selective Pd-catalyzed monoarylation of small primary alkyl amines through backbone-modification in ylide-functionalized phosphines (YPhos)
Ylide-substituted phosphines have been shown to be excellent ligands for C-N coupling reactions under mild reaction conditions. Here we report studies on the impact of the steric demand of the substituent in the ylide-backbone on the catalytic activity. Two new YPhos ligands with bulky ortho-tolyl (pinkYPhos) and mesityl (mesYPhos) substituents were synthesized, which are slightly more sterically demanding than their phenyl analogue but considerably less flexible. This change in the ligand design leads to higher selectivities and yields in the arylation of small primary amines compared to previously reported YPhos ligands. Even MeNH2 and EtNH2 could be coupled at room temperature with a series of aryl chlorides in high yields.
Rodstein, Ilja,Prendes, Daniel Sowa,Wickert, Leon,Paa?en, Maurice,Gessner, Viktoria H.
p. 14674 - 14683
(2020/12/29)

P(III)/P(V)-Catalyzed Methylamination of Arylboronic Acids and Esters: Reductive C-N Coupling with Nitromethane as a Methylamine Surrogate
The direct reductive N-arylation of nitromethane by organophosphorus-catalyzed reductive C-N coupling with arylboronic acid derivatives is reported. This method operates by the action of a small ring organophosphorus-based catalyst (1,2,2,3,4,4-hexamethylphosphetane P-oxide) together with a mild terminal reductant hydrosilane to drive the selective installation of the methylamino group to (hetero)aromatic boronic acids and esters. This method also provides for a unified synthetic approach to isotopically labeled N-methylanilines from various stable isotopologues of nitromethane (i.e., CD3NO2, CH315NO2, and 13CH3NO2), revealing this easy-to-handle compound as a versatile precursor for the direct installation of the methylamino group.
Li, Gen,Qin, Ziyang,Radosevich, Alexander T.
supporting information
p. 16205 - 16210
(2020/10/26)

Selective N -monomethylation of primary anilines with the controllable installation of N -CH2D, N -CHD2, and N -CD3units
The selective N-monomethylation of primary anilines was realized by the use of the Me3N-BH3/N,N-dimethylformamide (DMF) system as the methyl source. This method also allows for the controllable introduction of N-CH2D, N-CHD2, and N-CD3 units with high lev
Meng, Jing,Wang, Yi-Feng,Wang, Zhijuan,Xia, Hui-Min,Xu, Ai-Qing,Zhang, Feng-Lian
supporting information
p. 4922 - 4926
(2020/07/30)

EffectiveN-methylation of nitroarenes with methanol catalyzed by a functionalized NHC-based iridium catalyst: a green approach toN-methyl amines
Compound [IrBr(CO)2(κC-tBuImCH2PyCH2OMe)] featuring a flexible pyridine/OMe functionalized NHC ligand κ1C coordinated efficiently catalyzes the selectiveN-monomethylation of nitroarenes using methanol as both the reducing agent and the C1 source. A range of functionalized nitroarenes including heterocyclic or sterically hindered derivatives have been efficiently converted to the correspondingN-monomethyl amines in good yields at low catalyst loadings using sub-stoichiometric amounts of Cs2CO3as a base. Mechanistic investigations support a borrowing-hydrogen mechanism in which methanol acts as the hydrogen source and methylating agent. Further, the hydrogen transfer reduction of nitrobenzene to aniline under optimized reaction conditions should proceed through a direct mechanism involving nitrosobenzene andN-phenylhydroxylamine intermediates.
González-Lainez, Miguel,Jiménez, M. Victoria,Passarelli, Vincenzo,Pérez-Torrente, Jesús J.
p. 3458 - 3467
(2020/06/17)

Selective mono-N-methylation of nitroarenes with methanol catalyzed by atomically dispersed NHC-Ir solid assemblies
A series of N-heterocyclic carbene-iridium (NHC-Ir) coordination assemblies based on bis-pyrenoimidazolium salts are prepared, and shown to function as efficient solid molecular catalysts in selective mono-N-methylation of nitroarenes with methanol under mild conditions. The atomically dispersed active Ir(I) centers and the large π-conjugation rings endow the solid catalysts with an exceptionally high activity and selectivity for a broad substrate scope. Such solid NHC-Ir coordination assemblies are robust, which can be easily recovered and reused more than 10 runs without significant loss of their catalytic activity and selectivity. When combined with a subsequent formylation using the same solid catalysts under ambient conditions, this novel protocol can afford diverse formamides in excellent yields, further highlighting the applicability of the present solid catalysts for an efficient diversification of nitroarenes to a broad number of functional amines.
Chen, Jiangbo,Chen, Zhe-Ning,Tu, Tao,Wang, Jiaquan,Wen, Daheng,Wu, Jiajie,Xu, Xin,Zheng, Qingshu
p. 337 - 344
(2020/07/03)

Methoxycarbonylation of Alkyl-, Cycloalkyl-, and Arylamines with Dimethyl Carbonate in the Presence of Binder-Free Zeolite
Abstract: Methyl N-alkyl-, N-cycloalkyl-, and N-arylcarbamates were synthesized by reaction of the correspondingamines with dimethyl carbonate in the presence of binder-free FeHY zeolite. Theoptimal conditions (reactant ratio, amount of the catalyst, temperature,reaction time) were found to afford the target products with high yields.
Khazipova, A. N.,Khusnutdinov, R. I.,Mayakova, Yu. Yu.,Shchadneva, N. A.
p. 1228 - 1235
(2020/10/02)

Photon-initiated heterogeneous redox couples for methylation of anilines under mild conditions
Methylation of anilines has drawn a lot of attention due to their valuable applications and directly using methanol as a methylation reagent is of great advantage. Photon-initiated heterogeneous catalysis of this methylation process meets the requirements of green chemistry. Herein we show that balanced redox zones within carbon nitride supported Pd nanoparticles boost the selectivity of methylation of anilines under mild conditions.
Zhang, Bing,Gao, Hua,Wang, Wei
p. 4433 - 4437
(2020/08/10)

Iron-Catalyzed Regioselective α-C-H Alkylation of N-Methylanilines: Cross-Dehydrogenative Coupling between Unactivated C(sp3)-H and C(sp3)-H Bonds via a Radical Process
The iron-catalyzed α-C-H alkylation of N-methylanilines without any directing group by cross-dehydrogenative coupling between unactivated C(sp3)-H and C(sp3)-H bonds has been established for the first time, which provides a good complement to C(sp3)-H activation reactions and expands the field of Fe-catalyzed C-H functionalizations. Many different C(sp3)-H bonds in cyclic alkanes, cyclic ethers, and toluene derivatives can be used as coupling partners. Mechanistic investigations including the radical reaction process, the main role of various reagents, and the kinetic isotope effect experiment were also described.
Li, Ze-Lin,Sun, Kang-Kang,Wu, Peng-Yu,Cai, Chun
p. 6830 - 6839
(2019/06/14)

Efficient monomethylation synthesis method of aromatic primary amine
The invention relates to the field of organic synthesis, in particular to an efficient monomethylation synthesis method of aromatic primary amine. The method comprises the steps as follows: aromatic primary amine is used as a material to react with formaldehyde or paraformaldehyde, and a corresponding hexahydro-1,3,5-triaryl-1,3,5-triazine compound is obtained; the compound is subjected to catalytic hydrogenation under the action of a Pd/C catalyst, and a monomethylate of aromatic primary amine is obtained. The method has the greatest characteristics that the operation is simple, the conditionis mild, the raw material is cheap and easy to obtain, and the monomethylate of aromatic primary amine with high yield and high selectivity can be obtained. Posttreatment is simple, the production efficiency is improved, industrial mass production can be realized easily, and no equipment corrosion or environmental pollution can be caused.
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Paragraph 0026; 0029; 0030

(2019/05/15)

Catalytic Hydrogenation of Carboxamides with a Bifunctional Cp Ru Catalyst Bearing an Imidazol-2-ylidene with a Protic Aminoethyl Side Chain
Synthesis of a Cp Ru complex bearing an NH 2 -functionalized N -heterocyclic carbene (C-N H) was achieved by treatment of CpRuBr(isoprene) with an equimolar amount of a silver complex, which was generated from Ag 2 O and 1-(2-aminoethyl)-3-methylimidazolium bromide, in CH 3 CN at room temperature. The new CpRuBr(C-N H) complex showed a higher catalytic performance than the related CpRuCl(P-N H) and CpRuCl(N-N H) complexes. In the reaction of N -arylcarboxamides, the amine products were obtained in satisfactory yields under mild temperature conditions.
Ikariya, Takao,Kawano, Teruhiro,Kayaki, Yoshihito,Watari, Ryo
p. 2542 - 2547
(2019/06/08)

Sodium Triethylborohydride-Catalyzed Controlled Reduction of Unactivated Amides to Secondary or Tertiary Amines
The first transition-metal-free catalytic protocol for controlled reduction of amide functions using cheap and bench-stable hydrosilanes as reducing agents has been established. By altering the hydrosilane and solvent, the new method enables the selective cleavage of unactivated C-O bonds in amides and allows the C-N bonds to selectively break via the deacylated cleavage. Overall, this novel process may offer a versatile alternative to current methodologies employing stoichiometric metal systems for the controlled reduction of carboxamides.
Yao, Wubing,He, Lili,Han, Deman,Zhong, Aiguo
p. 14627 - 14635
(2019/12/02)

Highly selective hydrogenation of amides catalysed by a molybdenum pincer complex: Scope and mechanism
A series of molybdenum pincer complexes has been shown for the first time to be active in the catalytic hydrogenation of amides. Among the tested catalysts, Mo-1a proved to be particularly well suited for the selective C-N hydrogenolysis of N-methylated formanilides. Notably, high chemoselectivity was observed in the presence of certain reducible groups including even other amides. The general catalytic performance as well as selectivity issues could be rationalized taking an anionic Mo(0) as the active species. The interplay between the amide CO reduction and the catalyst poisoning by primary amides accounts for the selective hydrogenation of N-methylated formanilides. The catalyst resting state was found to be a Mo-alkoxo complex formed by reaction with the alcohol product. This species plays two opposed roles-it facilitates the protolytic cleavage of the C-N bond but it encumbers the activation of hydrogen.
Leischner, Thomas,Artús Suarez, Lluis,Spannenberg, Anke,Junge, Kathrin,Nova, Ainara,Beller, Matthias
p. 10566 - 10576
(2019/12/02)

Zr-MOF-808@MCM-41 catalyzed phosgene-free synthesis of polyurethane precursors
In this work, a catalytic method is presented for the synthesis of aromatic carbamates from aromatic amines using dimethyl carbonate instead of phosgene as a green and safe reaction process. Microcrystalline Zr-MOF-808 is reported as an active and efficient heterogeneous catalyst for the selective carbamoylation of anilines and industrially relevant aromatic diamines, under mild reaction conditions with near quantitative yields. We have accomplished the selective growth of well-dispersed Zr-MOF-808 nanocrystals within the mesoporous material MCM-41. A superior catalytic performance of the Zr-MOF-808@MCM-41 is demonstrated that together with increased stability stands out as an advantageous heterogeneous catalyst for polyurethane production. In situ FTIR studies have allowed a better understanding of the reaction pathway at the molecular level when the active MOF catalyst is present.
Rojas-Buzo, Sergio,García-García, Pilar,Corma, Avelino
p. 146 - 156
(2019/01/10)

Palladium-Catalyzed Methylation of Nitroarenes with Methanol
A procedure for the synthesis of N-methyl-arylamines directly from nitroarenes using methanol as green methylating agent was developed. The key to success is the use of a specific catalyst system consisting of palladium acetate and the ligand 1-[2,6-bis(isopropyl)phenyl]-2-[tert-butyl(2-pyridinyl)phosphino]-1H-Imidazole (L1). The generality of this protocol is demonstrated in the synthesis of more than 20 N-methyl-arylamines under comparably mild conditions. Combining this novel methodology with subsequent coupling processes using the same catalyst allows for efficient diversification of aromatic nitro compounds to a broad variety of amines including drug molecules.
Wang, Lin,Neumann, Helfried,Beller, Matthias
supporting information
p. 5417 - 5421
(2019/04/04)

Ru-Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
A ruthenium(II)-catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2-methylallyl)2(COD)], 1,1,1-tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding amines in high yields with excellent selectivities, and exhibits high tolerance toward functional groups including those that are reduction-sensitive. The choice of hydrogen source and acid co-catalyst is critical for catalysis. Mechanistic studies suggest that the reductive amination of the in situ generated alcohol and amine via borrowing hydrogen is the dominant pathway. (Figure presented.).
Pan, Yixiao,Luo, Zhenli,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
supporting information
p. 3800 - 3806
(2019/07/12)

Sodium Triethylborohydride-Catalyzed Controlled Reduction of Unactivated Amides to Secondary or Tertiary Amines
The first transition-metal-free catalytic protocol for controlled reduction of amide functions using cheap and bench-stable hydrosilanes as reducing agents has been established. By altering the hydrosilane and solvent, the new method enables the selective cleavage of unactivated C-O bonds in amides and allows the C-N bonds to selectively break via the deacylated cleavage. Overall, this novel process may offer a versatile alternative to current methodologies employing stoichiometric metal systems for the controlled reduction of carboxamides.
Yao, Wubing,He, Lili,Han, Deman,Zhong, Aiguo
(2019/11/14)

Binuclear rhodium complex containing ortho-carborane structure and preparation and application thereof
The invention relates to a binuclear rhodium complex containing an ortho-carborane structure and preparation and application thereof. The preparation method of the rhodium complex comprises the following steps: 1) adding an n-BuLi solution into an ortho-carborane solution, and then reacting for 30-60 min at room temperature; 2) adding selenium and reacting for 1-2h at room temperature; 3) adding [Cp*RhCl2]2, reacting at room temperature for 3-6h, and performing post-treating to obtain the rhodium complex; and the rhodium complex is used to catalyze arylamine N-methylation reaction to prepare arylamine N-methylated derivatives. Compared with the prior art, the preparation method of the binuclear semi-sandwich rhodium complex containing the ortho-carborane structure is simple and green, has excellent selectivity and higher yield, and the prepared rhodium complex has higher catalytic activity at room temperature, can be used for catalyzing aromatic amine N-methylation reaction to prepare the aromatic amine N-methylation derivatives, has high catalytic reaction yield, and has wide industrial application prospect.
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Paragraph 0043-0046

(2019/10/01)

Palladacycle-Phosphine Catalyzed Methylation of Amines and Ketones Using Methanol
Methylation of amines and ketones with palladacycle precatalyst has been performed using methanol as an environmentally benign reagent. Various ketones and amines undergo methylation reaction to yield monomethylated amines or ketones in moderate to good isolated yields. Moreover, this protocol was tested for the chemoselective methylation of 4-aminobenzenesulfonamide. The scope of the reaction was further extended to the deuteromethylation of ketones.
Mamidala, Ramesh,Biswal, Priyabrata,Subramani, M. Siva,Samser, Shaikh,Venkatasubbaiah, Krishnan
p. 10472 - 10480
(2019/08/20)

N -Methylation of ortho -substituted aromatic amines with methanol catalyzed by 2-arylbenzo [d] oxazole NHC-Ir(iii) complexes
Seven new chelated cyclometalated Ir complexes of ABON,P, ABON,O, and ABON,C(carbene) based on a rigid and tunable 2-arylbenzo[d]oxazole backbone have been prepared for the N-methylation of amines. Among these three coordinated modes, ABON,C(carbene)-chelated iridium-based catalysts exhibited good performance in the monomethylation of aromatic amines with methanol (MeOH) as the green methylation reagent. The steric-modified synthesis of ABON,C(carbene) complexes was described. The most active ABON,C(carbene) complex with marginal steric hindrance as a catalyst was obtained from the benzoxazole ring without a substituent and methyl group of the benzimidazole ring on the N-heterocyclic carbene (NHC) ligand. A variety of amines including para- and meta-substituted aromatic amines, as well as heterocyclic amines, were formulated as suitable substrates. Importantly, this catalyst considerably promoted the yield of the N-methylation of ortho-substituted aromatic amines. Controlled kinetic experiments and deuterium-labeling reactions of these ortho-substituted amines were conducted under optimized conditions. On the basis of the experimental results, a plausible mechanism was proposed.
Huang, Shuang,Hong, Xi,Cui, He-Zhen,Zhou, Quan,Lin, Yue-Jian,Hou, Xiu-Feng
p. 5072 - 5082
(2019/04/17)

Expedient stereospecific Co-catalyzed tandem C-N and C-O bond formation of: N -methylanilines with styrene oxides
Cobalt(ii)-catalyzed stereospecific coupling of N-methylanilines with styrene oxides is developed via tandem C-N and C-O bond formation using tert-butyl hydroperoxide (TBHP) as an oxidant. Optically active epoxide can be reacted with high optical purity.
Satheesh, Vanaparthi,Vivek Kumar, Sundaravel,Punniyamurthy, Tharmalingam
p. 11813 - 11816
(2018/12/01)

Method for selectively preparing N-monomethylamine compounds by using nitro compound as raw material
The invention discloses a method for selectively preparing N-monomethylamine compounds by using a nitro compound as a raw material. The method uses the nitro compound as the reaction raw material, formaldehyde as a methylating agent and a hydrogen gas as a reducing agent, in the presence of a supported type catalyst, a reaction is performed for 2-48 h at temperature of 10-180 DEG C in a reaction medium, and therefore the N-monomethylamine compounds are obtained, wherein the catalyst is at least one catalyst supported by palladium, platinum, ruthenium or rhodium. The method disclosed by the invention is simple, and can obtain the target product in a low-cost high-yield and high-selectivity manner; the method simplifies reaction steps, improves reaction efficiency, reduces reaction costs, and avoids separation of an intermediate product primary amine with high toxicity, easy deterioration and difficult storage; the method adopts the H2 as the reducing agent, thereby being clean, inexpensive and environmentally friendly; and the reaction conditions of the method are mild, and the catalyst is non-corrosive and easy to separate and reuse.
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Paragraph 0035; 0036

(2018/11/03)

The design, synthesis and evaluation of selenium-containing 4-anilinoquinazoline hybrids as anticancer agents and a study of their mechanism
Inhibition of tubulin polymerization is one of the significant strategies in the treatment of cancer. Inspired by the excellent antitumor activity of EP128495 and the beneficial biological activities of selenium compounds, a series of new selenium-containing 4-anilinoquinazoline hybrids were synthesized and evaluated as tubulin polymerization inhibitors. An anti-proliferative activity assay showed that most of the compounds inhibited human sensitive cancer cells at low nanomolar concentrations. A mechanism study revealed that the optimal compound 5a disrupted microtubule dynamics, decreased the mitochondrial membrane potential and arrested HeLa cells in the G2/M phase, finally resulting in cellular apoptosis.
An, Baijiao,Zhang, Shun,Hu, Jinhui,Pan, Tingting,Huang, Ling,Tang, Johnny Cheuk-On,Li, Xingshu,Chan, Albert S. C.
p. 4701 - 4714
(2018/07/03)

Highly Selective N-Monomethylanilines Synthesis from Nitroarene and Formaldehyde via Kinetically Excluding of the Thermodynamically Favorable N,N-Dimethylation Reaction
The synthesis of N-monomethylamine remains a challenging topic because the N,N-dimethylation reaction is thermodynamically favorable. In this work, the kinetically controlled N-monomethylamine synthesis from nitroarene and paraformaldehyde/H2 is reported to have superhigh N-monomethylamine selectivity in the presence of a Pd/TiO2 catalyst. The superior selectivity should be attributed to the preferential adsorption of the primary amine over N-monomethylamine on the Pd/TiO2 surface, as elucidated by NH3/Me2NH-TPD, while the excellent catalytic activity could be associated with the good H2 activation ability and high amine adsorbing capacity of the catalyst, as elucidated by NH3-TPD and H2-TPR tests. Good results were obtained with a variety of nitroarenes containing methyl, methoxyl, hydroxyl, fluoride, trifluoromethyl, ester, and amide substituents as starting materials, and the potential synthetic utility of this protocol in pharmaceutical is illustrated by N-monomethylation of drug molecules, such as clinidipine, nimesulide, procaine, and methyl aminosalicylate.
Wang, Hongli,Yuan, Hangkong,Yang, Benqun,Dai, Xingchao,Xu, Shan,Shi, Feng
p. 3943 - 3949
(2018/05/23)

Iron-Catalyzed Methylation Using the Borrowing Hydrogen Approach
A general iron-catalyzed methylation has been developed using methanol as a C1 building block. This borrowing hydrogen approach employs a Kn?lker-type (cyclopentadienone)iron carbonyl complex as catalyst (2 mol %) and exhibits a broad reaction scope. A variety of ketones, indoles, oxindoles, amines, and sulfonamides undergo mono- or dimethylation in excellent isolated yields (>60 examples, 79% average yield).
Polidano, Kurt,Allen, Benjamin D. W.,Williams, Jonathan M. J.,Morrill, Louis C.
p. 6440 - 6445
(2018/07/25)

Method for selectively preparing N-monomethylamine compound
The invention discloses a method for selectively preparing an N-monomethylamine compound. The method takes an amine compound, formaldehyde and H2 as reaction raw materials; the raw materials react in a reaction medium in the presence of a compound catalyst at 30 DEG C-180 DEG C for 2h-48h, so as to obtain the N-monomethylamine compound; and the compound catalyst is composed of oxides of at least two of the following metal or oxides of least one of the following metal and at least one metal simple substance: aluminum, copper, nickel, cobalt and iron. According to the method for preparing the N-monomethylamine compound, the conversion ratio and the selectivity of N-monomethylamine are relatively high; the H2 is used as a reducing agent and is clean, cheap and environment-friendly; the catalyst utilized by the method is cheap, simple to prepare and high in catalysis efficiency; and the method has mild preparation and reaction conditions and the catalyst has no corrosiveness, is easy to separate and can be repeatedly used.
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Paragraph 0027; 0032-0033

(2017/08/29)

Tandem Transformation of Nitro Compounds into N-Methylated Amines: Greener Strategy for the Utilization of Methanol as a Methylating Agent
A simple air- and moisture-stable, highly efficient ruthenium NNN pincer complex is reported for the first time to catalyze the tandem transformation of various aromatic and aliphatic nitro compounds into the corresponding N-methylated amines in up to 98 % yield by using methanol as a green methylating agent. Gram-scale reactions of challenging nitro substrates demonstrated the practical application aspects of this catalytic system. Importantly, the N-methylamine moiety could be smoothly introduced to various complex molecular structures without using any expensive palladium/phosphine/amine-based cross-coupling reactions.
Paul, Bhaskar,Shee, Sujan,Chakrabarti, Kaushik,Kundu, Sabuj
p. 2370 - 2374
(2017/06/13)

Novel nonmetal catalytic bidirectional selective reduction method of tertiary aromatic amide
The invention relates to a novel effective bidirectional selective environment-friendly method for hydrosilation reduction of tertiary aromatic amide and an organic silicon reagent. The method comprises the following steps: selecting a nonmetal catalytic system, and selectively preparing a secondary or tertiary organic amine compound by successively catalyzing tertiary aromatic amide and cheap PHMS or triethoxysilane under a mild condition. By adopting the method, the bidirectional selective reduction of the tertiary aromatic amide is realized by innovatively utilizing an electronic effect and steric hindrance difference of an organic silicon reagent at first time, so that a brand new strategy is provided for the reduction of amide and derivative of the amide, the defects of the traditional method that the substrate functional group is poor in compatibility, the production cost is high and the like can be overcome, and the application prospect of the amine compound prepared in industrial production or laboratory is promising.
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Paragraph 0054; 0055; 0056; 0057

(2017/10/22)

Efficient Cobalt-Catalyzed Methylation of Amines Using Methanol
The methylation of amines using methanol is a promising route to synthesize N-methylamines, and the development of cheap and efficient catalytic system for this reaction is of great significance. Herein, we reported a cobalt (Co)-based catalytic system, which was in situ formed from commercially available Co precursor and a tetradentate phosphine ligand P(CH2CH2PPh2)3 combined with K3PO4. This catalystic system was very effective for the selective production of dimethylated products from aliphatic amines and monomethylated ones from aromatic amines. The reaction mechanism was further investigated by control and isotope labelling experiments. (Figure presented.).
Liu, Zhenghui,Yang, Zhenzhen,Yu, Xiaoxiao,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Liu, Zhimin
supporting information
p. 4278 - 4283
(2017/10/23)

Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into γ-amino- N -Boc-enamines
Diaza [1,4] Wittig-type rearrangement of N-allylic-N-Boc-hydrazines into γ-amino-N-Boc-enamines was demonstrated. The scope and limitation, experimental mechanistic studies, and a proposed reaction mechanism were also described.
Tayama, Eiji,Kobayashi, Yoshiaki,Toma, Yuka
p. 10570 - 10573
(2016/09/02)

Methylation of aniline and its derivatives with dimethyl carbonate in the presence of binder-free micro-, meso-, and macroporous zeolites KNaX, NaY, and HY
Aniline and its derivatives undergo methylation when treated with dimethyl carbonate in the presence of binder-free micro-, meso-, and macroporous zeolites KNaX, NaY, and HY leading to the formation of N-methyl- and N,N-dimethylanilines.
Khusnutdinov,Shchadneva,Mayakova, Yu. Yu.,Ardieva,Khazipova,Kutepov
p. 1565 - 1570
(2017/01/28)

Iron-catalysed sequential reaction towards α-aminonitriles from secondary amines, primary alcohols and trimethylsilyl cyanide
We have developed a one-pot iron-catalysed sequential reaction of secondary amines with primary alcohols, trimethylsilyl cyanide and TBHP under mild reaction conditions to give the corresponding α-aminonitriles.
Shen, Hang,Hu, Liangzhen,Liu, Qing,Hussain, Muhammad Ijaz,Pan, Jing,Huang, Mingming,Xiong, Yan
supporting information
p. 2776 - 2779
(2016/02/19)

Mn(III)-based oxidative cyclization of N-aryl-3-oxobutanamides. facile synthesis and transformation of substituted oxindoles
The oxidation of 3-oxo-N-phenylbutanamides 1 with manganese(III) acetate in ethanol afforded dimeric 3,3'-biindoline-2,2'-dione derivatives 3-5. A similar reaction of N,2-disubstituted N-aryl-3-oxobutanamides 6 in acetic acid produced 3-acetylindolin-2-ones 7 bearing various substituents in good to excellent yields. The acetylindolinones 7 were easily deacetylated by treatment using neutral alumina in diethyl ether. Both the acetylindolinones 7 and deacetylated indolinones 8 were transformed by reduction into the substituted 1H-indoles.
Kikue, Nobutaka,Takahashi, Tetsuya,Nishino, Hiroshi
p. 540 - 562
(2015/03/04)

Supercritical methanol as solvent and carbon source in the catalytic conversion of 1,2-diaminobenzenes and 2-nitroanilines to benzimidazoles
Benzimidazoles and N-methylbenzimidazoles were synthesized by simply heating 1,2-diaminobenzenes in supercritical methanol over copper-doped porous metal oxides. These catalysts were derived from synthetic hydrotalcites that only contain earth-abundant starting materials. The carbon equivalents needed for the construction of the benzimidazole core originated from the solvent itself, which is known to undergo reforming to hydrogen and carbon monoxide through the formation of a formaldehyde intermediate. A variety of 1,2-diaminobenzenes were converted to the corresponding mixtures of benzimidazoles and N-methylated analogues in good yields. Interestingly, the more challenging, but readily available 2-nitroanilines, which require an additional reduction step prior to cyclization, could also be successfully converted to benzimidazoles in high selectivity. Furthermore, various other alcohols were applied besides methanol, to obtain 2-alkyl- and 1,2-dialkylbenzimidazoles. Preliminary mechanistic insights into the origins of N-alkylation as well as the reactivity of the nitro derivatives are discussed.
Sun, Zhuohua,Bottari, Giovanni,Barta, Katalin
p. 5172 - 5181
(2015/12/08)

Nickel-catalyzed amination of Aryl chlorides with ammonia or ammonium salts
The nickel-catalyzed amination of aryl chlorides to form primary arylamines occurs with ammonia or ammonium sulfate and a well-defined single-component nickel(0) precatalyst containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts. Simple alternative: The title reaction, which results in primary arylamines, is catalyzed by well-defined single-component nickel(0) precatalysts containing a Josiphos ligand and an η2-bound benzonitrile ligand. This system also catalyzes the coupling of aryl chlorides with gaseous amines in the form of their hydrochloride salts.
Green, Rebecca A.,Hartwig, John F.
supporting information
p. 3768 - 3772
(2015/03/18)

Room-temperature copper-catalyzed arylation of dimethylamine and methylamine in neat water
The first room-temperature copper-catalyzed arylations of dimethylamine and methylamine in neat water have been developed. Using a combination of CuI and 6,7-dihydroquinolin-8(5 H)-one oxime as catalyst, dimethylamine is arylated with various aryl halides to give the corresponding products in good to excellent yields. Further, this catalysis enables the selective arylation of methylamine to afford the high yields of monoarylated methylamines as the sole products.
Wang, Deping,Kuang, Daizhi,Zhang, Fuxing,Yang, Chunlin,Zhu, Xiaoming
supporting information
p. 714 - 718
(2015/03/18)

Efficient ruthenium-catalyzed N-methylation of amines using methanol
An in situ-generated complex from [RuCpCl2]2 and dpePhos ligand is reported as an efficient catalyst in the presence of 5 mol % of LiOtBu for the N-methylation of amines using methanol as the methylating agent at moderate conditions, following hydrogen borrowing strategy. This simple catalyst system provides selective N-monomethylation of substituted primary anilines and sulfonamides as well as N,N dimethylation of primary aliphatic amines in excellent yields at 40-100 °C with good tolerance to reducible functional groups. The catalytic intermediate CpRu(dpePhos)H was isolated and was shown to be active for methylation in the absence of base.
Dang, Tuan Thanh,Ramalingam, Balamurugan,Seayad, Abdul Majeed
p. 4082 - 4088
(2015/11/11)

Methanol dehydrogenation by iridium N-heterocyclic carbene complexes
A series of homogeneous iridium bis(N-heterocyclic carbene) catalysts are active for three transformations involving dehydrogenative methanol activation: acceptorless dehydrogenation, transfer hydrogenation, and amine monoalkylation. The acceptorless dehydrogenation reaction requires base, yielding formate and carbonate, as well as 2-3 equivalents of H2. Of the few homogeneous systems known for this reaction, our catalysts tolerate air and employ simple ligands. Transfer hydrogenation of ketones and imines from methanol is also possible. Finally, N-monomethylation of anilines occurs through a borrowing hydrogen reaction. Notably, this reaction is highly selective for the monomethylated product.
Campos, Jesús,Sharninghausen, Liam S.,Manas, Michael G.,Crabtree, Robert H.
p. 5079 - 5084
(2015/06/16)

N-Methylation of amine and nitro compounds with CO2/H2 catalyzed by Pd/CuZrOx under mild reaction conditions
An active Pd/ZrCuOx catalyst was prepared for the reductive amination of CO2. The N-methylation of amines and nitro compounds with CO2/H2 can be realized with up to 97% yield under relatively mild reaction condi
Cui, Xinjiang,Zhang, Yan,Deng, Youquan,Shi, Feng
supporting information
p. 13521 - 13524
(2015/01/09)

A facile and practical copper powder-catalyzed, organic solvent-and ligand-free ullmann amination of aryl halides
A facile and practical method that the copper powder-catalyzed Ullmann amination of aryl halides with aqueous methylamine under organic solvent-and ligand-free condition at 100 °C and in air gave N-arylamines as sole products in good to excellent yields. The presence of a small amount of air is essential. Other aliphatic primary amines show good to very high reactivity. Secondary amines and aniline are not reactive. Sensitive substituents (i.e., CHO, MeCO, CN and Cl) are tolerable in the reaction.
Jiao, Jiao,Zhang, Xi-Ru,Chang, Ning-Hui,Wang, Jie,Wei, Jun-Fa,Shi, Xian-Ying,Chen, Zhan-Guo
supporting information; experimental part
p. 1180 - 1183
(2011/04/24)

A facile protocol for the synthesis of mono-N-methyl anilines via formimidate intermediates
A general procedure for the preparation of mono-N-methyl anilines has been developed with excellent yields. This protocol relies on a NaBH3(OAc) reduction of formimidate intermediates that are quantitatively generated by treatment of primary substituted anilines with triethyl orthoformate under the catalysis of MCM-41-SO3H mesoporous zeolite. The newly developed procedure was facile, efficient, and environmentally benign.
Sun, Nan,Wang, Shuai,Mo, Weimin,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
experimental part
p. 7142 - 7148
(2010/09/14)

Selective monomethylation of anilines by Cu(OAc)2-promoted cross-coupling with MeB(OH)2
N-Methylanilines are readily synthesized in high yields through the copper(ll)-promoted coupling of anilines and methylboronic acid. This method represents a new approach for the selective monomethylation of anilines, and it is the first reported example
Gonzalez, Israel,Mosquera, Jesus,Guerrero, Cesar,Rodriguez, Ramon,Cruces, Jacobo
supporting information; experimental part
p. 1677 - 1680
(2009/09/06)

Highly specific N-monomethylation of primary aromatic amines
A synthetic methodology for the specific conversion of primary aromatic amines into their N-monomethyl derivatives under very mild conditions is presented. Anilines are treated with 4-nitrobenzenesulfonyl (nosyl) chloride to generate the corresponding sulfonamides 2 in high yields. The subsequent N-methylation reaction of the sulfonamides 2 with a solution of diazomethane is rapid and quantitative. Removal of the nosyl protecting group is readily carried out using the reagent system mercaptoacetic acid/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) affording the N-monomethylated aromatic amines 4. The procedure is convenient, efficient, and gives rise to the N-monomethyl-anilines exclusively.
Le Pera, Adolfo,Leggio, Antonella,Liguori, Angelo
p. 6100 - 6106
(2007/10/03)

Synthesis of primary amines and N-methylamines by the electrophilic amination of Grignard reagents with 2-imidazolidinone O-sulfonyloxime
2-Imidazolidinone O-sulfonyloxime reacts with various aryl and alkyl Grignard reagents as an electrophilic amination reagent, giving N-alkylated imines. The resulting imines are transformed to primary amines and N-methyl secondary amines by hydrolysis with CsOH and LiAlH4 reduction, respectively.
Kitamura, Mitsuru,Chiba, Shunsuke,Narasaka, Koichi
p. 1063 - 1070
(2007/10/03)

Desulfurization of thioureas, benzimidazoline-2-thiones and 1,3-dihydro-1,3-diaryl-2-thioxopyrimidine-4,6(2H,5H)-diones with nickel boride at ambient temperature
Nickel boride is reported to bring about desulfurization and reductive cleavage of N,N′-diarylthioureas to give corresponding anilines andN-methylanilines while N,N′-dialkylthioureas have been observed to undergo desulfurization to give formamidines; benzimidazoline-2-thiones are reported to undergo desulfurization to benzimidazoles and 1,3-dihydro-1,3-diaryl-2-thioxopyrimidine-4,6(2H,5H)-diones have been observed to yield corresponding hexahydropyrimidine-4,6-diones in high yields in dry methanol at ambient temperature.
Khurana, Jitender M.,Kukreja, Gagan,Bansal, Geeti
p. 2520 - 2524
(2007/10/03)

Aryltitanium species through the reaction of N,N-dialkylarylamines with TiCl4: Oxidative coupling, N-dealkylation, and reaction with electrophiles
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Periasamy, Mariappan,Jayakumar, K. Natarajan,Bharathi, Pandi
p. 3548 - 3550
(2007/10/03)