23896-88-0Relevant academic research and scientific papers
Copper-Catalyzed Cascade N-Dealkylation/N-Methyl Oxidation of Aromatic Amines by Using TEMPO and Oxygen as Oxidants
Li, Dianjun,Wang, Shihaozhi,Yang, Jiale,Yang, Jinhui
supporting information, p. 6768 - 6772 (2021/12/31)
A novel tandem N-dealkylation and N-methyl aerobic oxidation of tertiary aromatic amines to N-arylformamides using copper and TEMPO has been developed. This methodology suggested an alternative synthetic route from N-methylarylamines to N-arylformamides.
Acid-catalyzed chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines
Guo, Luxia,Chen, Zihao,Zhu, Hongmei,Li, Minghao,Gu, Yanlong
supporting information, p. 1419 - 1422 (2020/11/12)
Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a C[sbnd]C bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2,2-dimethoxyacetaldehyde reacted with aniline to form a new C[sbnd]N bond, in the presence of O2, via a C[sbnd]C bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new C[sbnd]O bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
HCl-mediated transamidation of unactivated formamides using aromatic amines in aqueous media
Dhawan, Sanjeev,Girase, Pankaj Sanjay,Kumar, Vishal,Karpoormath, Rajshekhar
, p. 3729 - 3739 (2021/10/14)
We report transamidation protocol to synthesize a range of secondary and tertiary amides from weakly nucleophilic aromatic and hetero-aryl amines with low reactive formamide derivatives, utilizing hydrochloric acid as catalyst. This current acid mediated strategy is beneficial because it eliminates the need for a metal catalyst, promoter or additives in the reaction, simplifies isolation and purification. Notably, this approach conventionally used to synthesize molecules on gram scales with excellent yields and a high tolerance for functional groups.
Palladium-catalyzed secondary benzylic imidoylative reactions
Wang, Chenglong,Wu, Licheng,Xu, Wentao,He, Feng,Qu, Jingping,Chen, Yifeng
supporting information, p. 6954 - 6959 (2020/09/15)
Reported herein is a palladium-catalyzed secondary benzylic imidoylative Negishi reaction leveraging the sterically bulky aromatic isocyanides as the imine source. This method allows the facile access of alkyl-, (hetero)aryl-, and alkynylzinc reagents to afford various α-substituted phenylacetone products under mild acidic hydrolysis, which are ubiquitous motifs in many pharmaceuticals and biologically active compounds. The diastereoselective reduction of imine can be accomplished to provide the expedient conversion of secondary benzylic halide into α-substituted phenethylamine derivatives with high atom economy.
A NHC-silyliumylidene cation for catalytic N?formylation of amines using carbon dioxide
Leong, Bi-Xiang,Teo, Yeow-Chuan,Condamines, Cloe,Yang, Ming-Chung,Su, Ming-Der,So, Cheuk-Wai
, p. 14824 - 14833 (2020/12/21)
This study describes the use of a silicon(II) complex, namely, the NHC-silyliumylidene cation complex [(IMe)2SiH]I (1, IMe =:C{N(Me)C(Me)}2), to catalyze the chemoselective N-formylation of primary and secondary amines using CO2 and PhSiH3 under mild conditions to afford the corresponding formamides as a sole product (average reaction time: 4.5 h; primary amines, average yield: 95%, average TOF: 8 h?1; secondary amines, average yield: 98%, average TOF: 17 h?1). The activity of 1 and product yields outperform the currently available non-transition-metal catalysts used for this catalysis. Mechanistic studies show that the silicon(II) center in complex 1 catalyzes the C?N bond formation via a different pathway in comparison with non-transition-metal catalysts. It sequentially activates CO2, PhSiH3, and amines, which proceeds via a dihydrogen elimination mechanism, to form formamides, siloxanes, and dihydrogen gas.
Tetracoordinate borates as catalysts for reductive formylation of amines with carbon dioxide
Du, Chen-Xia,Huang, Zijun,Jiang, Xiaolin,Li, Yuehui,Makha, Mohamed,Wang, Fang,Zhao, Dongmei
supporting information, p. 5317 - 5324 (2020/09/17)
We report sodium trihydroxyaryl borates as the first robust tetracoordinate organoboron catalysts for reductive functionalization of CO2. These catalysts, easily synthesized from condensing boronic acids with metal hydroxides, activate main group element-hydrogen (E-H) bonds efficiently. In contrast to BX3 type boranes, boronic acids and metal-BAr4 salts, under transition metal-free conditions, sodium trihydroxyaryl borates exhibit high reactivity of reductive N-formylation toward a variety of amines (106 examples), including those with functional groups such as ester, olefin, hydroxyl, cyano, nitro, halogen, MeS-, ether groups, etc. The over-performance to catalyze formylation of challenging pyridyl amines affords a promising alternative method to the use of traditional formylation reagents. Mechanistic investigation supports electrostatic interactions as the key for Si/B-H activation, enabling alkali metal borates as versatile catalysts for hydroborylation, hydrosilylation, and reductive formylation/methylation of CO2.
Preparation method of 2-methoxy-4-nitroaniline
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Paragraph 0074; 0075, (2019/06/12)
The invention discloses a preparation method of 2-methoxy-4-nitroaniline. The preparation method comprises the following steps of: carrying out acetylation reaction of o-methoxyaniline and acetic acid, discharging water generated in the acetylation reaction process from a reaction system, dropwisely adding fuming nitric acid into the prepared acetic acid solution of the o-methoxyacetanilide to carry out nitration reaction, adding deionized water after the nitration reaction is finished and then filtering, adding the prepared 2-methoxy-4-nitroaniline into an alkali solution to carry out hydrolysis reaction; after the hydrolysis reaction is finished, cooling the prepared reaction solution, and filtering to obtain 2-methoxy-4-nitroaniline. By adopting the method to synthesize 2-methoxy-4-nitroaniline, the acylation reaction cost is low, the nitration reaction selectivity is high, the discharge of three wastes is reduced, the production cost is reduced, the product purity is high, the yield is high, and the 2-methoxy-4-nitroaniline has a good industrial application value.
Visible-light-induced radical cascade cyclization of oxime esters and aryl isonitriles: Synthesis of cyclopenta[: B] quinoxalines
Yuan, Yao,Dong, Wu-Heng,Gao, Xiao-Shuang,Xie, Xiao-Min,Zhang, Zhao-Guo
supporting information, p. 11900 - 11903 (2019/10/11)
A visible-light-induced radical cascade cyclization of aryl isonitriles and cyclobutanone oxime esters for the synthesis of cyclopenta[b]quinoxalines has been accomplished for the first time. The key to the success of this process was the integration of the in situ-formed nitrile radical followed by the cascade radical isonitrile/nitrile insertion-cyclization. The easy introduction of substituents for both substrates and the high functional group tolerance of the reaction make it an efficient strategy to give various quinoxaline derivatives in moderate to good yields.
An efficient method for the N-formylation of amines under catalyst- and additive-free conditions
Xu, Zhuo-Wei,Xu, Wen-Yi,Pei, Xiao-Jun,Tang, Fei,Feng, Yi-Si
supporting information, p. 1254 - 1258 (2019/04/10)
A simple catalyst- and additive-free method for the N-formylation of amines has been developed. The advantages of this protocol include a wide range of functional group tolerance, high efficiency and a lack of required extra promoters under mild conditions. This convenient strategy will provide a facile synthesis towards N-formamide natural products and pharmaceutical derivatives. A mechanism that involves difluorocarbene is proposed for this reaction.
Mn-Catalyzed Selective Double and Mono-N-Formylation and N-Methylation of Amines by using CO2
Huang, Zijun,Jiang, Xiaolin,Zhou, Shaofang,Yang, Peiju,Du, Chen-Xia,Li, Yuehui
, p. 3054 - 3059 (2019/04/10)
Functionalization of amines by using CO2 is of fundamental importance considering the abundance of amines and CO2. In this context, the catalytic formylation and methylation of amines represent convenient and successful protocols for selective CO2 utilization as a C1 building block. This study represents the first example of selective catalytic double N-formylation of aryl amines by using a dinuclear Mn complex in the presence of phenylsilane. This robust system also allows for selective formylation and methylation of amines under a range of conditions.
