- Reductive Alkylation of Amines with Carboxylic Ortho Esters
-
We have demonstrated for the first time that carboxylic ortho esters could be used as an alkylating agent in the reductive alkylation of amines. A variety of amines, including amino acid esters, were alkylated affording mono-alkylated products with high selectivity in practical to high yields using standard heterogeneous catalysts. By applying acyclic ortho esters alkylation was completed at room temperature. (Figure presented.).
- Kadyrov, Renat,Moebus, Konrad
-
supporting information
p. 3352 - 3357
(2020/07/04)
-
- Palladium-Catalyzed Synthesis of N, N-Dimethylanilines via Buchwald-Hartwig Amination of (Hetero)aryl Triflates
-
This work delineates the synthesis of N,N-dimethylaniline derivatives from dimethylamines and aryl triflates. The palladium-catalyzed C-N bond formation proceeds in excellent yields, using an unsophisticated catalytic system, a mild base, and triflates as electrophiles, which are readily available from inexpensive phenols. N,N-Dimethylanilines are multifunctional reaction partners and represent useful but underutilized building blocks in organic synthesis.
- Pospech, Jola,Taeufer, Tobias
-
p. 7097 - 7111
(2020/06/27)
-
- N-Methylation and Trideuteromethylation of Amines via Magnesium-Catalyzed Reduction of Cyclic and Linear Carbamates
-
A new reduction of carbamates to N-methyl amines is presented. The magnesium-catalyzed reduction reaction allows the conversion of cyclic and linear carbamates, including N-Boc protected amines, into the corresponding N-methyl amines and amino alcohols which are of significant interest due to their presence in many biologically active molecules. Furthermore, the reduction can be extended to the formation of N-trideuteromethyl labeled amines.
- Magre, Marc,Szewczyk, Marcin,Rueping, Magnus
-
supporting information
p. 3209 - 3214
(2020/04/10)
-
- Extremely Active Ethylene Tetramerization Catalyst Avoiding the Use of Methylaluminoxane: [iPrN{P(C6H4-p-SiR3)2}2CrCl2]+[B(C6F5)4]?
-
Sasol's original ethylene tetramerization catalyst requires the use of expensive MMAO, a low working temperature (~60 °C), and generates polyethylene (PE) as a side product. In this study, we developed an upgraded catalytic system that successfully avoids the need for MMAO. [(PNP)CrCl2]+[B(C6F5)4]?-type species was obtained from the reaction of CrCl3(THF)3, [PhN(H)Me2]+[B(C6F5)4]?, and iPrN[P(C6H4-p-Si(nBu)3)2]2 (2) as well as from simply reacting 2 with [CrCl2(NCCH3)4]+[B(C6F5)4]?. The bulky (nBu)3Si-substituents play the crucial role of preventing the formation of the inactive [(PNP)2CrCl2]+[B(C6F5)4]?. The prepared [2-CrCl2]+[B(C6F5)4]? combined with iBu3Al was extremely active ('4000 kg/g-Cr/h), performed well at a high temperature of up to 90 °C, and generated a negligible amount of PE (0.03 wt%). Screening the performance with a series of iPrN[P(C6H4-p-SiR3)2]2 further supported that bulky R3Si-substituents are crucial not only to achieve extremely high activities but also to minimize the generation of PE. Structure of a [(PNP)CrCl2]+[B(C6F5)4]? species was elucidated by X-ray crystallography.
- Park, Hee Soo,Kim, Tae Hee,Baek, Jun Won,Lee, Hyun Ju,Kim, Tae Jin,Ryu, Ji Yeon,Lee, Junseong,Lee, Bun Yeoul
-
p. 4351 - 4359
(2019/08/01)
-
- N -Monomethylation of amines using paraformaldehyde and H2
-
The selective N-monomethylation of amines is an important topic in fine chemical synthesis. Herein, for the first time, we described a selective N-monomethylation reaction of amines with paraformaldehyde and H2 in the presence of a CuAlOx catalyst. A variety of amines, including primary aromatic amines, benzylamine and cyclohexylamine, as well as secondary amines, have been shown to be compatible with this reaction.
- Wang, Hongli,Huang, Yongji,Dai, Xingchao,Shi, Feng
-
supporting information
p. 5542 - 5545
(2017/07/06)
-
- An experimental and theoretical study on the preparation of 4,4′-methylene-bis(N,N-dimethylaniline) in ionic liquid
-
The reaction of N,N-dimethylaniline with tetrachloromethane in ionic liquid was found to give 4,4′-methylene-bis (N,N-dimethylaniline) in considerable yield. The ionic liquid was prepared from N,N-dimethylaniline which is also the one of raw materials for the preparation of 4,4′-methylene-bis (N,N-dimethylaniline), and acts as both solvent and catalyst in the reaction. Mild reaction conditions, enhanced rates, improved yields, and reagents' reactivity which is different from that in conventional organic solvents are the remarkable features observed in ionic liquids. In addition, the results of calculations are in good accordance with the experimental outcomes.
- Wang, Yun
-
p. 276 - 280
(2016/05/24)
-
- Selective monomethylation of primary amines with simple electrophiles
-
Direct monomethylation of primary amines with methyl triflate was achieved with high selectivity (up to 96%). The key point of this single methyl transfer stems from the use of HFIP as the solvent that interferes with amines and avoids overmethylation.
- Lebleu, Thomas,Ma, Xiaolu,Maddaluno, Jacques,Legros, Julien
-
supporting information
p. 1836 - 1838
(2014/02/14)
-