94-68-8Relevant academic research and scientific papers
Production process of alkaline red intermediate 3-ethylamino-p-methylphenol
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Paragraph 0060-0062, (2021/03/31)
The invention relates to a production process of an alkaline red intermediate 3-ethylamino p-methylphenol. The production process specifically comprises the following steps: step 1, an alkylation reaction: carrying out alkylation reaction on o-toluidine and absolute ethyl alcohol under the action of a catalyst magnetic solid acid to generate an alkylate mixture; and then rectifying the alkylate mixture to obtain the N-ethyl o-toluidine; wherein the reaction temperature of the alkylation reaction is 60-120 DEG C; wherein the addition amount of the magnetic solid acid is 4-6% of the mass ratio of the feed liquid; step 2, a sulfonation reaction: carrying out sulfonation reaction on the N-ethyl o-toluidine and fuming sulfuric acid to generate 3ethylamino-p-toluenesulfonic acid; step 3, a hydroxylation reaction: carrying out hydroxylation reaction on 3ethylamino p-toluenesulfonic acid and potassium hydroxide to generate 3-ethylamino p-methylphenol potassium salt; and step 4, acid precipitation: reacting the 3-ethylamino p-methylphenol potassium salt with hydrochloric acid to prepare the 3-ethylamino p-methylphenol. The production process is high in yield and short in reaction time.
Selective Pd-catalyzed monoarylation of small primary alkyl amines through backbone-modification in ylide-functionalized phosphines (YPhos)
Rodstein, Ilja,Prendes, Daniel Sowa,Wickert, Leon,Paa?en, Maurice,Gessner, Viktoria H.
, p. 14674 - 14683 (2020/12/29)
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.
Homogeneous cobalt-catalyzed deoxygenative hydrogenation of amides to amines
Papa, Veronica,Cabrero-Antonino, Jose R.,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
, p. 6116 - 6128 (2020/11/03)
The first general and efficient cobalt-catalyzed deoxygenative hydrogenation of amides to amines is presented. The optimal catalytic system based on a combination of [Co(NTf2)2] and (p-anisyl)triphos (L3) in the presence of [Me3SiOTf] as acidic co-catalyst facilitates the direct hydrogenation of a broad range of amides to the corresponding amines under mild conditions. A set of control experiments indicate that, after the initial reduction of the amide carboxylic group to the well-known hemiaminal intermediate, the reaction mainly proceeds through C-O bond cleavage though other pathways might be also involved to a minor extent. This journal is
Hydrogenation and: N-Alkylation of anilines and imines via transfer hydrogenation with homogeneous nickel compounds
Benitez-Medina, G. Eliad,García, Juventino J.
supporting information, p. 17579 - 17587 (2019/12/23)
The nickel-catalyzed N-Alkylation of a variety of arylamines via transfer hydrogenation in the absence of pressurized hydrogen and basic or acidic additives was achieved in a tandem reaction. This process was further extended to the CN bond reduction and N-Alkylation of a variety of imines with ethanol, the latter acting as a hydrogen and acetaldehyde source, which allowed for the reduction and subsequent condensation to yield the corresponding N-Alkylated products.
Alkylation of Aromatic Amines with Trialkyl Amines Catalyzed by a Defined Iridium Complex with a 2-Hydroxypyridylmethylene Fragment
Deng, Danfeng,Hu, Bowen,Zhang, Ziyu,Mo, Shengkai,Yang, Min,Chen, Dafa
, p. 2218 - 2226 (2019/05/21)
Six Cp?Ir complexes containing NN-bitentate chelate ligands [Cp?IrCl(C5H4CH2C5H3OH)][Cl] (1), [Cp?IrCl(C5H4CH2C5H3O)] (2), [Cp?IrCl(C5H4C5H3OH)] [Cl] (3), [Cp?IrCl(C5H4CH2C5H4)][Cl] (4), [Cp?IrCl(CH3OC5H3CH2C5H3OCH3)][Cl] (5), and [Cp?IrCl(CH3OC5H3CH2C5H3OH)][Cl] (6) were synthesized and characterized. Complex 1 could be transformed to 2 when reacted with NaOtBu or NEt3 via -OH deprotonation. These six complexes were tested as catalysts for mono-N-alkylation of amines with trialkyl amines, and complex 1 exhibited highest activity. The coupling reactions proceed under air condition, with 1 mol % catalyst loading without extra base in methanol at 120 °C and can be further accelerated by adding NR3·HCl.
Ru-Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
Pan, Yixiao,Luo, Zhenli,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
supporting information, p. 3800 - 3806 (2019/07/12)
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.).
Tailored Cobalt-Catalysts for Reductive Alkylation of Anilines with Carboxylic Acids under Mild Conditions
Liu, Weiping,Sahoo, Basudev,Spannenberg, Anke,Junge, Kathrin,Beller, Matthias
supporting information, p. 11673 - 11677 (2018/09/10)
The first cobalt-catalyzed hydrogenative N-methylation and alkylation of amines with readily available carboxylic acid feedstocks as alkylating agents and H2 as ideal reductant is described. Combination of tailor-made triphos ligands with cobalt(II) tetrafluoroborate significantly improved the efficiency, thus promoting the reaction under milder conditions. This novel protocol allows for a broad substrate scope with good functional group tolerance, even in the presence of reducible alkenes, esters, and amides.
Towards a general ruthenium-catalyzed hydrogenation of secondary and tertiary amides to amines
Cabrero-Antonino, Jose R.,Alberico, Elisabetta,Junge, Kathrin,Junge, Henrik,Beller, Matthias
, p. 3432 - 3442 (2016/05/19)
A broad range of secondary and tertiary amides has been hydrogenated to the corresponding amines under mild conditions using an in situ catalyst generated by combining [Ru(acac)3], 1,1,1-tris(diphenylphosphinomethyl)ethane (Triphos) and Yb(OTf)3. The presence of the metal triflate allows to mitigate reaction conditions compared to previous reports thus improving yields and selectivities in the desired amines. The excellent isolated yields of two scale-up experiments corroborate the feasibility of the reaction protocol. Control experiments indicate that, after the initial reduction of the amide carbonyl group, the reaction proceeds through the reductive amination of the alcohol with the amine arising from collapse of the intermediate hemiaminal.
Boron Lewis Acid Promoted Ruthenium-Catalyzed Hydrogenation of Amides: An Efficient Approach to Secondary Amines
Yuan, Ming-Lei,Xie, Jian-Hua,Zhou, Qi-Lin
, p. 3036 - 3040 (2016/10/11)
The hydrogenation of amides to amines has been developed by using the catalyst [Ru(H)2(CO)(Triphos)] (Triphos=1,1,1-tri(diphenylphosphinomethyl)ethane) and catalytic boron Lewis acids such as B(C6F5)3 or BF3?Et2O as additives. The reaction provides an efficient method for the preparation of secondary amines from amides in good yields with high selectivity.
Deoxygenative Hydrogenation of Amides Catalyzed by a Well-Defined Iridium Pincer Complex
Yuan, Ming-Lei,Xie, Jian-Hua,Zhu, Shou-Fei,Zhou, Qi-Lin
, p. 3665 - 3669 (2016/07/06)
The iridium-catalyzed highly chemoselective hydrogenation of amides to amines has been developed. Using a well-defined iridium catalyst bearing a P(O)C(O)P pincer ligand combined with B(C6F5)3, the C-O cleavage products are formed under mild reaction conditions. The reaction provides a new method for the preparation of amines from amides in good yield with high selectivity.
