305849-49-4Relevant articles and documents
Direct amidation of non-activated carboxylic acid and amine derivatives catalyzed by TiCp2Cl2
Wang, Hui,Dong, Wei,Hou, Zhipeng,Cheng, Lidan,Li, Xiufen,Huang, Longjiang
, (2020/02/15)
This paper described a mild and efficient direct amidation of non-activated carboxylic acid and amine derivatives catalyzed by TiCp2Cl2. Arylacetic acid derivatives reacted with different amines to afford the corresponding amides in good to excellent yield except of aniline. Aryl formic acids failed to react with aniline but smoothly reacted with aliphatic amines and benzylamine in moderate to good yield, fatty acids reacting with benzyl and aliphatic amines give amides in good to excellent yield. Chiral amino acids derivatives were transformed into amides without racemization in moderate yield. The possible mechanism of direct amidation catalyzed by TiCp2Cl2 was discussed. This catalytic method is very suitable for the amidation of low sterically hindered arylacetic acid, fatty acids with different low sterically hindered amines except aniline, as well as the amidation of aryl formic acid with benzyl and aliphatic amines.
Latent Bronsted Base Solvent-Assisted Amide Formation from Amines and Acid Chlorides
Otsuka, Rikuto,Maruhashi, Kazuo,Ohwada, Tomohiko
supporting information, p. 2041 - 2057 (2018/05/04)
Weakly basic amines, including even neutral amines such as nitroaniline and aminocarboxylic acids, react with acid chlorides very efficiently in N, N -dimethylacetamide (DMAC), without addition of a base, to give the corresponding amides in high yields. The role of DMAC and related solvents as latent Bronsted bases was studied in these amidation reactions. Less basic amines, such as aromatic amines, reacted with benzoyl chloride faster than more basic aliphatic amines.
Hafnium-catalyzed direct amide formation at room temperature
Lundberg, Helena,Adolfsson, Hans
, p. 3271 - 3277 (2015/06/16)
Herein, the first example of a metal-catalyzed protocol for direct amidation of nonactivated carboxylic acids at ambient temperature (26 °C) is presented. The mild reaction conditions give rise to high yields of a range of amides in reaction times as short as 90 min, employing a commercial hafnium complex, [Hf(Cp)2Cl2], as catalyst. Amino acids are transformed into their corresponding amides without racemization, and the catalyst displays full selectivity for the amidation of carboxylic acids over esters. Electronic properties of the carboxylic acids were found to have a strong influence on the rate of the amidation reaction, and the need for a balanced amount of molecular sieves was observed to be highly important for optimal reaction outcome.