545350-99-0Relevant academic research and scientific papers
Near-Ambient-Temperature Dehydrogenative Synthesis of the Amide Bond: Mechanistic Insight and Applications
Kar, Sayan,Xie, Yinjun,Zhou, Quan Quan,Diskin-Posner, Yael,Ben-David, Yehoshoa,Milstein, David
, p. 7383 - 7393 (2021)
The current existing methods for the amide bond synthesis via acceptorless dehydrogenative coupling of amines and alcohols all require high reaction temperatures for effective catalysis, typically involving reflux in toluene, limiting their potential practical applications. Herein, we report a system for this reaction that proceeds under mild conditions (reflux in diethyl ether, boiling point 34.6 °C) using ruthenium PNNH complexes. The low-temperature activity stems from the ability of Ru-PNNH complexes to activate alcohol and hemiaminals at near-ambient temperatures through the assistance of the terminal N-H proton. Mechanistic studies reveal the presence of an unexpected aldehyde-bound ruthenium species during the reaction, which is also the catalytic resting state. We further utilize the low-temperature activity to synthesize several simple amide bond-containing commercially available pharmaceutical drugs from the corresponding amines and alcohols via the dehydrogenative coupling method.
Mesoporous niobium oxide spheres as an effective catalyst for the transamidation of primary amides with amines
Ghosh, Subhash Chandra,Li, Cheng Chao,Zeng, Hua Chun,Ngiam, Joyce S. Y.,Seayad, Abdul M.,Chen, Anqi
, p. 475 - 484 (2014/05/20)
Mesoporous niobium oxide spheres (MNOS), conveniently prepared by a novel antisolvent precipitation approach, have been shown to be an effective catalyst for the transamidation of primary amides with amines. This novel transamidation can be efficiently carried out under solvent-free conditions and is applicable to a wide range of primary amides and amines to provide N-alkyl amides in good to excellent yields. The catalyst is highly stable and reusable. The application of this transamidation reaction has been demonstrated in the synthesis of antidepressant drug moclobemide and other druglike compounds.
