7432-60-2Relevant academic research and scientific papers
Syntheses, structures and catalytic activities of low-coordinated rare-earth metal complexes containing 2,2′-pyridylpyrrolides
Du, Jun,Zhou, Shuangliu,Zhang, Xiuli,Zhang, Lijun,Cui, Peng,Huang, Zeming,Wei, Yun,Zhu, Xiancui,Wang, Shaowu
, (2019/11/20)
Reactions of the ligand precursors 2-(2′-pyridyl)-3,5-Me2-pyrrole (L1H) and 2-(2-pyridyl)-3,4,5-Me3-pyrrole (L2H) with [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 in toluene afforded a series of low-coordinated rare-earth metal bis-amido complexes L1RE[N(SiMe3)2]2 [RE = Y (1a), Dy (1b), Er (1c), Yb (1d)] and L2RE[N(SiMe3)2]2 [RE = Y (2a), Dy (2b), Er (2c), Yb (2d)]. With the ionic radius of rare-earth metal increasing, the reaction of L1H and [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 gave dinuclear complexes (L1)2RE(μ-Cl)(μ-η5:η1:η1-L1)RE(L1)[N(SiMe3)2]2 [RE = Sm (1e), Pr (1f)]; however, the reaction of L2H and [(Me3Si)2N]3Sm(μ-Cl)Li(THF)3 afforded (L2)2Sm[N(SiMe3)2]2 (2e). Results indicated that the ionic radius of rare-earth metal and subtle change in the ligands have substantial effects on the structure and bonding mode of complexes. The complexes showed a high catalytic activity for the ring-opening reaction of cyclohexene oxide with amines to afford various β-aminoalcohols under mild solvent-free conditions.
M-Type SrFe12O19Ferrite: An Efficient Catalyst for the Synthesis of Amino Alcohols under Solvent-Free Conditions
Laayati, Mouhsine,Hasnaoui, Ali,Abdallah, Nayad,Oubaassine, Saadia,Fkhar, Lahcen,Mounkachi, Omar,El Houssame, Soufiane,Ait Ali, Mustapha,El Firdoussi, Larbi
, (2020/08/05)
Magnetically separable strontium hexaferrite SrFe12O19 was prepared using the chemical coprecipitation method, and the nanostructured material was characterized by X-ray diffraction, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and BET analysis. The SEM images showed the homogeneity of the chemical composition of SrFe12O19 and uniform distribution of size and morphology. The pore size of the nanomaterial and its specific area were determined by BET measurements. Strontium hexaferrite SrFe12O19 exhibited a strong magnetic field, which is highly suitable in the heterogeneous catalysis as it can be efficiently separated from the reaction. The magnetic nanocatalyst showed high activity and environmentally benign heterogeneous catalysts for the epoxide ring-opening with amines affording β-amino alcohols under solvent-free conditions. When unsymmetrical epoxides were treated in the presence of aromatics amines, the regioselectivity was influenced by the electronic and steric factors. Total regioselectivity was observed for the reactions performed with aliphatic amines. The magnetically SrFe12O19 nanocatalyst showed excellent recyclability with continuously good catalytic activities after four cycles.
Tetragonal versus hexagonal: Structure-dependent catalytic activity of Co/Zn bimetallic metal-organic frameworks
Pariyar, Anand,Asl, Hooman Yaghoobnejad,Choudhury, Amitava
, p. 9250 - 9257 (2016/09/28)
Tetragonal and hexagonal phases of monometallic Zn and bimetallic Co/Zn metal-organic frameworks (MOFs), with secondary building units (SBUs) containing a M3O (M = metal) cluster, were synthesized from identical constituents using a benzenetricarboxylate (BTC3-) linker that forms decorated 3,6- and 3,5-connected networks, respectively. There exist subtle differences between the SBUs; one of the metal atoms in the M3O cluster in the tetragonal phase has one dissociable DMF solvent molecule while that in the hexagonal phase has three. Connectivities between the SBUs form one-dimensional channels in both MOFs. These MOFs catalyze the chemoselective addition of amines to epoxides, giving exclusively β-hydroxyamine under heterogeneous conditions. A ring-opening reaction of a symmetrical epoxide showed that the hexagonal phase diastereoselectively yields trans-alcohol, exhibiting an exquisite model for structure-dependent activity.
Amino alcohols in organocatalysed acylation and deacylation: The effect of dialkylamino substituents on the rate
Wessjohann, Ludger A.,Zhu, Mingzhao
supporting information; experimental part, p. 107 - 112 (2009/04/08)
In alcohols and esters, a neighbouring dialkylamino group can enhance the reactivity towards acylation and deacylation, respectively, that is, such amino alcohols can act as transacylation catalysts like DMAP. This effect is dependent on the number of (carbon) spacer atoms, flexibility of the molecule and the presence and position of further heteroatoms. Based on this effect, the site selective acylation and deacylation of desmycosin, a macrocycle antibiotic possessing an amino sugar moiety, is described.
Highly chemoselective addition of amines to epoxides in water
Azizi, Najmodin,Saidi, Mohammad R.
, p. 3649 - 3651 (2007/10/03)
(Chemical Equation Presented) Aminolysis of a variety of epoxides by aliphatic and aromatic amines in water, in the absence of any catalyst with high yields, is reported. β-Amino alcohols were formed under mild conditions with high selectivity and in excellent yields.
Solid lithium perchlorate as a powerful catalyst for the synthesis of β-aminoalcohols under solvent-free conditions
Azizi, Najmodin,Saidi, Mohammad R.
, p. 505 - 507 (2007/10/03)
Lithium perchlorate catalyzed the ring opening of epoxides with amines to provide the corresponding β-aminoalcohols in excellent yields with high regioselectivity. The reaction proceeds rapidly under mild and neutral conditions and worked well with primary, secondary, aliphatic, aromatic, and hindered amines in short times at room temperature, in the absence of solvent.
Regioselective ring opening of epoxides by nucleophiles mediated by lithium bistrifluoromethanesulfonimide
Cossy, Janine,Bellosta, Véronique,Hamoir, Claire,Desmurs, Jean-Roger
, p. 7083 - 7086 (2007/10/03)
In the presence of LiNTf2, epoxides undergo ring opening with high regioselectivity and in good yield when they are treated with nucleophiles such as amines, hydrazines and thiophenol.
Dibasic benzo[b]thiophene derivatives as a novel class of active site directed thrombin inhibitors: 4. SAR studies on the conformationally restricted C3-side chain of hydroxybenzo[b]thiophenes
Takeuchi, Kumiko,Kohn, Todd J.,Sall, Daniel J.,Denney, Michael L.,McCowan, Jefferson R.,Smith, Gerry F.,Gifford-Moore, Donetta S.
, p. 759 - 764 (2007/10/03)
A novel series of benzo[b]thiophene diamine thrombin inhibitors with a conformationally restricted C3-side chain 3 was investigated. The constrained C3-side chain by a cyclohexyl ring contributed to not only an additive but also a synergistic effect on the thrombin inhibitory activity. The SAR studies resulted in the discovery of a potent thrombin inhibitor 27 that was over 750-fold more potent than the initial lead compound 1.
Lanthanide(III) trifluoromethanesulfonates as extraordinarily effective new catalysts for the aminolysis of 1,2-epoxides
Chini, Marco,Crotti, Paolo,Favero, Lucilla,Macchia, Franco,Pineschi, Mauro
, p. 433 - 436 (2007/10/02)
Lanthanide(III) trifluoromethanesulfonates (triflates), such as Yb(OTf)3, Nd(OTf)3 and Gd(OTf)3, catalyze in a extraordinarily efficient way the aminolysis of 1,2-epoxides, affording the corresponding β-amino alcohols, at
Regio- and Stereo-selective Ring Opening of Epoxides with Amide Cuprate Reagents
Yamamoto, Yoshinori,Asao, Naoki,Meguro, Masaki,Tsukada, Naofumi,Nemoto, Hisao,et al.
, p. 1201 - 1203 (2007/10/02)
Amide cuprate reagents attack the less hindered carbon atom of epoxides to give 1,2-amino alcohols in good yields; this procedure is applied to the synthesis of an aziridine alcohol bearing a carborane framework which is a potentially useful 10B carrier for boron neutron capture therapy.
