17373-29-4Relevant academic research and scientific papers
N-Methylation of amines and nitroarenes with methanol using heterogeneous platinum catalysts
Jamil, Md.A.R.,Touchy, Abeda S.,Rashed, Md. Nurnobi,Ting, Kah Wei,Siddiki, S.M.A. Hakim,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-ichi
, p. 47 - 56 (2019/02/07)
We report herein the selective N-methylation of amines and nitroarenes with methanol under basic conditions using carbon-supported Pt nanoparticles (Pt/C) as a heterogeneous catalyst. This method is widely applicable to four types of N-methylation reactions: (1) N,N-dimethylation of aliphatic amines under N2, (2) N-monomethylation of aliphatic amines under 40 bar H2, (3) N-monomethylation of aromatic amines under N2, and (4) tandem synthesis of N-methyl anilines from nitroarenes and methanol under 2 bar H2. All these reactions under the same catalytic system showed high yields of the corresponding methylamines for a wide range of substrates, high turnover number (TON), and good catalyst reusability. Mechanistic studies suggested that the reaction proceeded via a borrowing hydrogen methodology. Kinetic results combined with density functional theory (DFT) calculations revealed that the high performance of Pt/C was ascribed to the moderate metal–hydrogen bond strength of Pt.
Recycling of homogeneous catalysts in reactive ionic liquid-solvent-free aminofunctionalizations of alkenes
Fa?bach, Thiemo A.,Kirchmann, Robin,Behr, Arno,Vorholt, Andreas J.
supporting information, p. 5243 - 5249 (2017/11/09)
The catalyst in homogeneously catalyzed aminofunctionalizations is often difficult to recycle, making these reactions expensive on an industrial scale. The use of dimethylammonium dimethylcarbamate (dimcarb) as a reactive ionic liquid provides an elegant solution to this challenge, as it is a substrate and polar phase at the same time. In this work, homogeneously transition-metal catalyzed reactions-specifically hydroamination, telomerization and hydroaminomethylation-are carried out in neat substrates without additional solvents. The ionic character of dimcarb enables the immobilization of the active catalysts in the reactive ionic liquid, using sulfonated ligands. Investigations regarding the hydroamination of 1,3-dienes led to a total turnover number (TTON) of more than 8700 with β-farnesene in 12 repetitive recycling experiments. The telomerization of 1,3-butadiene was carried out over 30 consecutive runs without any loss of activity, resulting in a TTON of more than 90 000.
PROCESS FOR MAKING LONG CHAIN INTERNAL FATTY TERTIARY AMINES
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Page/Page column 17; 18, (2010/11/30)
The invention relates to a process for preparing long chain internal fatty amines, quaternized amines and amine oxides and selected amine oxides having a symmetric alkyl portion.
Competing Hydride Transfer and Ene Reactions in the Aminoalkylation of 1-Alkenes with N,N-Dimethylmethyleniminium Ions. A Literature Correction
Cohen, Theodore,Onopchenko, Anatoli
, p. 4531 - 4537 (2007/10/02)
A literature report that N,N-dimethylmethyleniminium ion (2) reacts with propylene and styrene to form unsaturated tertiary amines is shown to be incorrect.The major products are the secondary amines 1-(methylamino)butane and 1-(methylamino)-3-phenylpropane in which N-demethylation has occurred along with the saturation of the alkene.Analogous major products are formed with 1-butene, 1-hexene, 1-octene, 1-dodecene, 1-tetradecene, p-methylstyrene, and m-nitrostyrene as substrates.When the substrates are isobutylene, 2-ethyl-1-hexene, α-methylstyrene, and p-methoxystyrene, the major products are tertiary amines, but the secondary amines are also formed in smaller yields.The small yields of tertiary amines obtained in the cases of styrene and p-methylstyrene were increased by going from solvent acetic acid to acetonitrile and by increasing the branching of the alkyl groups on nitrogen.The internal olefins 5-decene and cyclohexene were far less reactive, giving only 3-4percent of amine products that were mainly tertiary in the former case and secondary in the latter.It is concluded that tertiary amine products are favored by an alkene structure and a solvent that favors the formation of a stable carbenium ion intermediate or a transition state with substantial carbenium ion character upon electrophilic attack of the iminium ion on the alkene.The secondary amine products are favored when a carbenium ion is of low stability and when the β-carbon atom of the olefin and/or the alkyl group attached to nitrogen is sterically unhindered; such hindrance decreases the rate of hydride ion transfer that is believed to occur in the production of secondary amines.
