Zirconium catalyzed amide formation without water scavenging
作者:Helena Lundberg、Fredrik Tinnis、Hans Adolfsson
DOI:10.1002/aoc.5062
日期:2019.9
A scalable homogeneous metal‐catalyzed protocol for direct amidation of carboxylic acids is presented. The use of 2–10 mol% of the commercially available Zr(Cp)2(OTf)2·THF results in high yields of amides at moderate temperature, using an operationally convenientreaction protocol that circumvents the use of water scavenging techniques.
Efficient and accessible silane-mediated direct amide coupling of carboxylic acids and amines
作者:Melissa C. D'Amaral、Nick Jamkhou、Marc J. Adler
DOI:10.1039/d0gc02833a
日期:——
A straightforward method for the direct synthesis of amides from amines and carboxylicacids without exclusion of air or moisture using diphenylsilane with N-methylpyrrolidine has been developed. Various amides are made efficiently, and broad functional group compatibility is shown through a Glorius robustness study. A gram-scale synthesis demonstrates the scalability of this method.
carboxylic acid and aminederivatives 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
Direct Amide Coupling of Non-activated Carboxylic Acids and Amines Catalysed by Zirconium(IV) Chloride
作者:Helena Lundberg、Fredrik Tinnis、Hans Adolfsson
DOI:10.1002/chem.201104055
日期:2012.3.26
Amidst the green: A green, mild and effective protocol for the direct formation of secondary and tertiary amides from non‐activated carboxylicacids and amines in good to excellent yields by employing ZrCl4 as the catalyst is presented (see scheme). The amidecoupling protocol proved to be suitable for scaled up syntheses, and the mild reaction conditions conserve the enantiopurity of chiral starting
from nitroalkanes and amines. In contrast to traditional oxidative catalysis, this catalytic system involves reversing the polarities of two catalytic components (umpolung) by means of a hypervalentiodinereagent. A variety of functional groups were tolerated in the reaction, suggesting that they have the potential for use in other types of oxidative catalytic reactions.