2362-77-8Relevant articles and documents
Catalyst-free dynamic exchange of aromatic Schiff base bonds and its application to self-healing and remolding of crosslinked polymers
Lei, Zhou Qiao,Xie, Pu,Rong, Min Zhi,Zhang, Ming Qiu
, p. 19662 - 19668 (2015)
The present work reveals that catalyst-free dynamic reversible exchange of aromatic Schiff base bonds is enabled at room temperature. Attachment of aryl groups to both nitrogen and carbon atoms of carbon-nitrogen double bonds is a critical structural factor that contributes to the dynamic characteristics and complete reaction between aromatic aldehyde and aromatic amine. The exchange mechanism is studied by model compounds, and free radical intermediates are found to be involved in the non-equilibrium stage of the exchange reaction. By taking advantage of the dynamic equilibrium of aromatic Schiff base bonds, infusible and insoluble crosslinked polyacrylate is self-healed and reprocessed through rearrangement of macromolecular networks. The reprocessed polymer is still self-healable. Either the self-healing or reprocessing is completed in air without heating. Considering that Schiff base polymers have shown diverse properties and stimulus-response behaviors, activation of the dynamic exchange of the inherent Schiff base bonds would result in a series of novel functionalities. More interestingly, traditional crosslinked polymers might thus be provided with a facile way of being smarter.
Stereoselective synthesis of new β-lactams from the main functional group of indomethacin
Amiri, Mojgan,Islami, Mohammad Reza,Mortazavi, Zahra Fahimeh al-Sadat
, (2022/01/31)
New β-lactams were synthesized in moderate yields from indomethacin, which is currently used as a drug to relieve pain such as arthritis, muscle and bone damage. The reaction was carried out by [2 + 2] cycloaddition of the in situ formed indomethacinyl ke
Fe2Mn(μ3-O)(COO)6 Cluster Based Stable MOF for Oxidative Coupling of Amines via Heterometallic Synergy
Wang, Ying-Xia,Wang, Hui-Min,Meng, Pan,Song, Dong-Xia,Qi, Zhikai,Zhang, Xian-Ming
, p. 2983 - 2989 (2021/08/30)
The direct catalytic oxidative coupling of amines is one of the attracting methods for the synthesis of a variety of pharmaceutical or industrial needed imines. Numerous earth-abundant manganese based salts, oxides, and complexes have been applied in this reaction. However, these compounds suffered from difficult separation, large catalyst loading, complicated reactivation or indeterminate activity. Considering the facts that metal-organic frameworks (MOFs) with crystalline structure, precise composition, and enormous surface area have superior performance in heterogeneous catalytic reactions, herein, we introduced Mn into [Fe3(μ3-O)(CH3COO)6], one of the precursors for the preparation of stable MOFs, and got [Fe2Mn(μ3-O)(CH3COO)6] cluster. After ligand replacement with biphenyl-3,4’,5-tricarboxylic acid (BPTC), heterometallic cluster-based [Fe2Mn(μ3-O)(BPTC)2(DMF)2(H2O)] (1) was obtained. As expected, 1 is stable and able to catalyze the homo- or cross-coupling of amines effectively and selectively with 0.9 mol% catalyst loading at room temperature. Control experiments indicated that the catalytic activity of 1 mainly stems from Mn sites and that Fe synergistically contributes to the stability. Additionally, 1 is recyclable and can be reused easily for at least 8 runs without obvious decrease in catalytic ability. To our knowledge, 1 should be the first heterometallic cluster-based MOF with defined structure suitable for the synthesis of diverse imines from oxidative coupling of amines under mild conditions, which may shed light on the easy preparation of effective heterogeneous catalysts for organic synthesis.
Ru(II)-NHC catalysed N-Alkylation of amines with alcohols under solvent-free conditions
Karaca, Emine ?zge,Dehimat, Zieneb Imene,Ya?ar, Sedat,Gürbüz, Nevin,Tebbani, Dahmane,?etinkaya, Bekir,?zdemir, ?smail
, (2021/04/02)
The reaction of [RuCl2(p-cymene)]2 with in situ prepared Ag-N-heterocyclic carbene (NHC) complexes yields a series of [RuCl2(p-cymene)(NHC)] complexes (2). All of the complexes have been characterised by elemental analysis, and 1H NMR and 13C NMR spectroscopies. These complexes have been tested for the N-alkylation of aromatic amines with arylmethyl alcohols under neat conditions in the presence of KOtBu at 120 °C. Compounds (2) are stable and have high catalytic/selective activity for the N-alkylation reactions of primary amines to afford secondary amines.
