7581-94-4Relevant articles and documents
Synthesis and application of Cu(II) immobilized MCM-41 based solid Lewis acid catalyst for aminolysis reaction under solvent-free condition
Chaudhary, Garima,Gupta, Neha,Singh, Amit Pratap
, (2021/07/22)
In this paper, a Cu(II) immobilized periodic mesoporous organosilica (PMOs) was synthesized and used as a reusable solid Lewis acid catalyst for the aminolysis of epoxides under solvent-free conditions. An amide-based ligand, L-propylsilyl (1) having a specific binding pocket was prepared and fabricated on mesoporous MCM-41 to produce mesoporous organosilica L-propylsilyl@MCM-41 (2). Further, it has been utilized for anchoring Cu(II) ions under controlled reaction conditions to yield solid Lewis acid catalyst Cu(II)-L-propylsilyl@MCM-41 (3). The synthesized catalyst 3 exhibits significantly higher catalytic activity for aminolysis compared to hitherto known solid Lewis acid catalysts. An extensive range of β-amino alcohols with high regio and stereoselectivity were prepared by using catalyst 3. The catalyst was recovered easily and reused eight times without any loss in its catalytic activity. Furthermore, the synthesis of clinically significant propranolol (β-blocker) from α- naphthyl glycidyl ether was attained successfully using catalyst 3 in a very decent yield.
Heterogeneous ring-opening reactions and Knoevenagel condensation reactions with cobalt complexes: Effect of CoII versus CoIII states on catalysis
Kumar, Sushil,Gupta, Rajeev
, p. 843 - 852 (2020/06/26)
This work illustrates comparative catalytic performance of two sets of cobalt complexes within a common macrocyclic ligand environment: CoII complexes 1 and 2 versus CoIII complexes 3 and 4. All four cobalt complexes functioned as the heterogeneous catalysts for the ring-opening reactions of assorted epoxides as well as Knoevenagel condensation reactions of assorted aldehydes. Cobalt(II) complexes were noted to be the superior catalysts over cobalt(III) complexes for both types of organic transformations. The observed difference in the catalytic performance of two sets of cobalt complexes has been related to the kinetic differences between CoII versus CoIII ions. All four cobalt complexes display high catalytic efficiency and excellent reusability without any apparent loss in the catalytic performance.
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.
