- 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)
-
- Selective utilization of methoxy groups in lignin for: N -methylation reaction of anilines
-
The utilization of lignin as a feedstock to produce valuable chemicals is of great importance. However, it is a great challenge to produce pure chemicals because of the complex structure of lignin. The selective utilization of specific groups on lignin molecules offers the possibility of preparing chemicals with high selectivity, but this strategy has not attracted attention. In this work, we propose a protocol to produce methyl-substituted amines by the selective reaction of the methoxy groups of lignin and aniline compounds. It was found that LiI in the ionic liquid 1-hexyl-3-methylimidazolium tetrafluoroborate could catalyze the reaction efficiently and the selectivity to the N-methylation product could be as high as 98%. Moreover, the lignin was not depolymerized in the reaction. As it was rich in hydroxyl groups, the residual material left over after the reaction was used as an efficient co-catalyst for the cycloaddition of epoxy propane with CO2, using KI as the catalyst.
- Mei, Qingqing,Shen, Xiaojun,Liu, Huizhen,Liu, Hangyu,Xiang, Junfeng,Han, Buxing
-
p. 1082 - 1088
(2019/02/03)
-
- Method for preparing important chemicals by using lignin as methyl sources
-
The invention relates to preparation of important chemical products by using methoxyl groups in lignin. According to a method, methyl provided by the lignin reacts with carbon monoxide and water underthe catalysis effects of catalysts to obtain acetic acid; reaction is performed with aminated compounds to obtain N-methylation products. The methoxyl groups in the lignin are used for preparing important chemical products for the first time; an important and continuous production path is provided for the preparation of various important chemical products.
- -
-
Paragraph 0097; 0098; 0120-0124
(2019/06/12)
-
- 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)
-
- METHOD FOR THE METHYLATION OF NITROGEN-CONTAINING ORGANIC COMPOUNDS
-
A method for the methylation of amines, amides and imines comprises the step of reacting these compounds with CO2 and H2 in the presence of a Ruthenium-phosphine complex.
- -
-
Page/Page column 9
(2015/01/16)
-
- Method for the methylation of nitrogen-containing Organic Compounds
-
A method for the methylation of amines, amides and imines comprises the step of reacting these compounds with CO2 and H2 in the presence of a Ruthenium-phosphine complex.
- -
-
Paragraph 0039; 0042
(2015/01/18)
-
- Electrophilic fluorination of N,N-dimethylaniline, N,N-dimethylnaphthalen- 1-amine and 1,8-bis(dimethylamino)naphthalene with N-F reagents
-
Reaction of N,N-dimethylaniline, N,N-dimethylnaphthalen-1-amine and 1,8-bis(dimethylamino)- naphthalene (proton sponge) with 1-chloromethyl-4- fluorodiazonia-bicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor) and N-fluorobenzenesulfonimide (NFSI) h
- Sorokin, Vladimir I.,Pozharskii, Alexander F.,Ozeryanskii, Valery A.
-
-
- Ruthenium-catalyzed direct methylation of primary and secondary aromatic amines using carbon dioxide and molecular hydrogen
-
The effective catalytic N-methylation of anilines using CO2 as C1 source and molecular hydrogen as reducing agent was demonstrated using the well-defined [Ru(triphos)(tmm)] catalyst. Secondary and primary (shown) aromatic amines were mono- or dialkylated, respectively, in high yields. N-methylation of amides coupled with the amide hydrogenation offers an efficient approach to unsymmetrical tertiary methyl/alkyl/aromatic amines. Copyright
- Beydoun, Kassem,Vom Stein, Thorsten,Klankermayer, Juergen,Leitner, Walter
-
supporting information
p. 9554 - 9557
(2013/09/23)
-
- Large-scale preparation of aromatic fluorides via electrophilic fluorination with functionalized aryl- or heteroarylmagnesium reagents
-
Functionalized aryl- or heteroarylmagnesium reagents, prepared from the corresponding bromides or iodides using halogen-magnesium exchange or direct magnesium insertion in the presence of lithium chloride, reacted smoothly with N-fluorobenzenesulfonimide, (PhSO2)2NF, in the mixed solvent (4:1 CH2Cl2-perfluorodecalin) to give the corresponding aromatic fluorides in moderate to good yields. Georg Thieme Verlag Stuttgart · New York.
- Yamada, Shigeyuki,Knochel, Paul
-
experimental part
p. 2490 - 2494
(2010/09/04)
-
- Convenient electrophilic fluorination of functionalized aryl and heteroaryl magnesium reagents
-
"Chemical Equation Presented" Cive me an "F": Electrophilic fluorination of various aromatic and heteroaromatic Grignard reagents is smoothly performed with (PhSO2)2NF as fluorinating agent in a 4:1 mixture of CH2Cl2/ perfluorodecalin (see scheme). This solvent system allows minimization of most side reactions.
- Yamada, Shigeyuki,Gavryushin, Andrei,Knochel, Paul
-
supporting information; experimental part
p. 2215 - 2218
(2010/06/19)
-
