39895-56-2Relevant articles and documents
Complexation of 5-aminovaleric acid zwitterions in aqueous/methanol solution by heterotopic tri-cationic receptors
Cichowicz, Grzegorz,Pi?tek, Piotr,Walczak, Wojciech,Zakrzewski, Maciej
, p. 694 - 699 (2020)
Heterotopic tri-cationic receptors based on 4,10,16-triaza-18-crown-6 are capable of efficient and selective binding of the zwitterionic form of 5-aminovaleric acid (5-AVA) in aqueous/methanol solution. The cooperative participation of both cation and ani
Chiral molecular recognition in a tripeptide benzylviologen cyclophane host
Gavin, Julia A.,Garcia, Maurie E.,Benesi, Alan J.,Mallouk, Thomas E.
, p. 7663 - 7669 (1998)
A cationic chiral cyclophane was synthesized and studied as a host for chiral and racemic π-donor molecules. The cyclophane host has a rigid binding cavity flanked by (S)-(valine-leucine-alanine) and N,N'-dibenzyl- 4,4'-bipyridinium subunits, which allow for hydrogen-bonding and π-stacking interactions with included aromatic guest molecules. 1H NMR binding titrations were performed with several different pharmaceutically interesting guest molecules including β-blockers, NSAIDs, and amino acids and amino acid derivatives. The host-guest complexation constants were generally small for neutral and cationic guests (0-39 M-1 at 20 °C in water/acetone mixtures. However, a (R)/(S) enantioselectivity ratio of 13 ± 5 was found for DOPA, a strongly π-donating cationic guest. Two-dimensional NOESY 1H NMR spectra confirm that (R)-DOPA binds inside the cavity of the host and that there is no measurable interaction of the cavity with (S)-DOPA under the same conditions.
Green and convenient protocols for the efficient reduction of nitriles and nitro compounds to corresponding amines with NaBH4 in water catalyzed by magnetically retrievable CuFe2O4 nanoparticles
Zeynizadeh, Behzad,Mohammad Aminzadeh, Farkhondeh,Mousavi, Hossein
, (2019/03/23)
Abstract: In this study, firstly, CuFe2O4 nanoparticles were prepared by a simple operation. The structure of the mentioned nanoparticles was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, inductively coupled plasma-optical emission spectrometry, vibrating sample magnetometer and also Brunauer–Emmett–Teller and Barrett–Joyner–Halenda analyses. The prepared magnetically copper ferrite nanocomposite was successfully applied as a simple, cost-effective, practicable, and recoverable catalyst on the green, highly efficient, fast, base-free, and ligand-free reduction of nitriles and also on the affordable and eco-friendly reduction of nitro compounds with the broad substrate scope to the corresponding amines with NaBH4 in water at reflux in high to excellent yields. Graphical abstract: [Figure not available: see fulltext.].
A ppm level Rh-based composite as an ecofriendly catalyst for transfer hydrogenation of nitriles: Triple guarantee of selectivity for primary amines
Liu, Lei,Li, Jifan,Ai, Yongjian,Liu, Yuhong,Xiong, Jialiang,Wang, Hongdong,Qiao, Yijun,Liu, Wenrui,Tan, Shanchao,Feng, Shaofei,Wang, Kunpeng,Sun, Hongbin,Liang, Qionglin
, p. 1390 - 1395 (2019/03/26)
Hydrogenation of nitriles to afford amines under mild conditions is a challenging task with an inexpensive heterogeneous catalyst, and it is even more difficult to obtain primary amines selectively because of the accompanying self-coupling side reactions. An efficient catalytic system was designed as Fe3O4@nSiO2-NH2-RhCu@mSiO2 to prepare primary amines through the transfer hydrogenation of nitrile compounds with economical HCOOH as the hydrogen donor. The loading of rhodium in the catalyst could be at the ppm level, and the TOF reaches 6803 h-1 for Rh. This catalytic system has a wide substrate range including some nitriles that could not proceed in the previous literature. The experimental results demonstrate that the excellent selectivity for primary amines is guaranteed by three tactics, which are the strong active site, the inhibition of side products by the hydrogen source and the special pore structure of the catalyst. In addition, the catalyst could be reused ten times without activity loss through convenient magnetic recovery.
