1499-53-2Relevant articles and documents
Highly efficient and recyclable copper based ionic liquid catalysts for amide synthesis
Rani, Poonam,Srivastava, Rajendra
, p. 7162 - 7170 (2016)
A series of Cu based ionic liquids was synthesized by the reaction of 1-butyl-3-methylimidazolium salts and copper(ii) salts. These ionic liquids were investigated as catalysts in the synthesis of amides (primary, secondary and tertiary amides). For easy separation and recycling, the Cu based ionic liquids were decorated on nanocrystalline silicalite. The materials were characterized using powder X-ray diffraction, nitrogen adsorption, scanning and transmission electron microscopy, thermogravimetric analysis, and nuclear magnetic resonance, Fourier transform infrared and UV-visible spectroscopy. The Cu based ionic liquids decorated on nanocrystalline silicalite were found to be efficient and recyclable catalysts for the amide synthesis. The catalysts were found to be stable and show negligible loss of the activity even after five cycles.
Preparation of α-amino acids: via Ni-catalyzed reductive vinylation and arylation of α-pivaloyloxy glycine
Chen, Yanchi,Gong, Hegui,Guo, Jiandong,Tao, Xianghua,Wang, Xiaotai
, p. 220 - 226 (2021/01/14)
This work emphasizes easy access to α-vinyl and aryl amino acids via Ni-catalyzed cross-electrophile coupling of bench-stable N-carbonyl-protected α-pivaloyloxy glycine with vinyl/aryl halides and triflates. The protocol permits the synthesis of α-amino acids bearing hindered branched vinyl groups, which remains a challenge using the current methods. On the basis of experimental and DFT studies, simultaneous addition of glycine α-carbon (Gly) radicals to Ni(0) and Ar-Ni(ii) may occur, with the former being more favored where oxidative addition of a C(sp2) electrophile to the resultant Gly-Ni(i) intermediate gives a key Gly-Ni(iii)-Ar intermediate. The auxiliary chelation of the N-carbonyl oxygen to the Ni center appears to be crucial to stabilize the Gly-Ni(i) intermediate.
3,6-Di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) catalysed metal-free amide bond formation from thioacids and amines at room temperature
Samanta, Suvendu,Ray, Shounak,Bhaduri, Samanka Narayan,Samanta, Partha Kumar,Biswas, Papu
supporting information, (2020/08/10)
A 3,6-di(pyridin-2-yl)-1,2,4,5-tetrazine (pytz) catalysed efficient, mild and metal-free method has been developed for direct amide bond synthesis from simple thioacids and amines as starting materials. This methodology is useful for aromatic, aliphatic, and heteroaromatic thioacids as well as primary, secondary, heterocyclic, and even functionalized amines. A wide substrates scope, operationally mild conditions, and acylation of amines without affecting other functional groups such as alcohols, esters, carbodithioates, among others make this strategy very attractive and practical.