64353-78-2Relevant academic research and scientific papers
Tungsten-Catalyzed Transamidation of Tertiary Alkyl Amides
Feng, Fang-Fang,Liu, Xuan-Yu,Cheung, Chi Wai,Ma, Jun-An
, p. 7070 - 7079 (2021/06/30)
Transamidation has recently emerged as a straightforward and convenient means to diversify amides. However, the kinetically and thermodynamically demanding transamidation of notoriously robust, fully alkyl-substituted tertiary amides still remains a longstanding challenge. Here, we describe a method for the activation of tertiary alkyl amides to streamline transamidation using simple tungsten(VI) chloride as a catalyst and chlorotrimethylsilane as an additive. The highly electrophilic and oxophilic tungsten catalyst enables the selective scission of a C-N bond of tertiary alkyl amides to effect transamidation of a myriad of structurally and electronically diverse tertiary alkyl amides and amines. Mechanistic study implies that the synergistic effect of the catalyst and the additive could pronouncedly induce the nucleophilic acyl substitution of tertiary alkyl amide with amine to realize transamidation.
Mechanism of the reaction of carbodiimides with carboxylic acids
Schotman, A. H. M.
, p. 319 - 324 (2007/10/02)
The kinetic parameters of the reaction of diphenylcarbodiimide with various carboxylic acids have been determined at a temperature interval of 20-160 deg C.The classical scheme for the reaction of carbodiimides with carboxylic acids is extended.It has been found that, at high temperatures, amides and isocyanates are the end products of the reactions.N-Acylureas, initially formed from aromatic carbodiimides and carboxylic acids, dissociate into isocyanates and amides at temperatures above 60 deg C.N-Acylureas formed by the reaction of carboxylic acids with aliphatic carbodiimides prove to be more stable: their dissociation temperature is about 50 deg C higher.Both the formation and dissociation of N-acylureas are much faster when the parent acid is stronger.
