93098-67-0Relevant articles and documents
Co-Polymeric Nanosponges from Cellulose Biomass as Heterogeneous Catalysts for amine-catalyzed Organic Reactions
Riva, Laura,Punta, Carlo,Sacchetti, Alessandro
, p. 6214 - 6222 (2020/10/02)
Heterogeneous catalysts prepared from biomass waste sources are attracting increasing interest. The reasons rely on the possibility of combining the virtuous approach of circular economy with the consolidated advantages of heterogeneous catalysis, namely the recycling of the system and the possibility to drive selectivity towards desired products. Herein we report a highly porous cellulose-based nanosponge (CNS) and its use as a recoverable catalyst for Henry and Knoevenagel reactions, two classical amino-catalyzed transformations. The material is obtained by cross-linking between TEMPO-oxidized cellulose nanofibers (TOCNF) and branched polyethyleneimine 25 kDa (bPEI) in the presence of citric acid. CNS have been developed as sorbent materials for water remediation but their use as heterogeneous catalysts was never investigated. The fully characterized micro- and nano-porous system guarantees a complete penetration of CNS, allowing reagents to diffuse within. Indeed, by modulating reaction conditions (catalyst loading, temperature, solvent, microwave versus conventional heating, relative ratio of reagents) it was possible to drive selectivity towards the desired products, while maintaining high efficiency in terms of conversion. The catalyst could be re-used several times without losing in catalytic efficiency. In most cases the products’ distribution is quite different from homogeneous conditions, this much more emphasizing the importance of this heterogeneous solution.
Solvent-Free FeCl3-Assisted Electrophilic Fluorine-Catalyzed Knoevenagel Condensation to Yield α,β-Unsaturated Dicarbonyl Compounds and Coumarins
Yang, Lu,Zhu, Jiang,Xie, Fukai,Peng, Xiaoshi,Lin, Bin,Liu, Yongxiang,Cheng, Maosheng
, p. 1053 - 1060 (2019/09/06)
A highly environmentally friendly procedure was developed for the Knoevenagel condensation of aromatic aldehydes with diethyl malonate in the presence of FeCl3 and N-fluorobenzenesulfonimide as a source of electrophilic fluorine under solvent-free conditions. The scope of the reaction was explored using commercially available substrates. The reaction with substituted salicylaldehydes afforded the corresponding coumarin derivatives which attract interest due to their potential medicinal importance.
Copper-catalysed domino reaction of 2-bromobenzylidenemalonates and 1,3-dicarbonyls for the synthesis of chromenes
Saebang, Yotsakorn,Rukachaisirikul, Vatcharin,Kaeobamrung, Juthanat
supporting information, p. 168 - 171 (2016/12/26)
4H-Chromenes were synthesized from 2-bromobenzylidenemalonates and 1,3-dicarbonyls under mild and simple reaction conditions via copper-catalysed domino reactions involving Michael addition and intramolecular Ullmann-type C(aryl)–O bond formation. Althoug
Diastereoselective construction of spirocyclic pyrrolidines bearing two quaternary centers via CuII-P, N-Ligand catalyzed 1,3-dipolar cycloaddition
Tang, Li-Wei,Li, Chuan,Zhao, Bao-Jing,Lan, Li,Zhang, Man,Zhou, Zhi-Ming
supporting information, p. 923 - 930 (2017/01/28)
Here, we report a convenient access to diastereoselective synthesis of polysubstituted pyrrolidines bearing a unique spiro quaternary center at the C-2 position and another quaternary center at C-4. The synthesis system, CuII/P, N-Ligand-cataly
Asymmetric michael addition of N-tert-butanesulfinyl imidate with α,β-unsaturated diesters: Scope and application to the synthesis of indanone derivatives
Wang, Jinfang,Zhou, Yu,Zhang, Lei,Li, Zeng,Chen, Xianjie,Liu, Hong
supporting information, p. 1508 - 1511 (2013/06/27)
An additive-free and highly diastereoselective Michael addition reaction of an N-tert-butanesulfinyl imidate to α,β-unsaturated diesters has been developed using LDA as a base with good to excellent yields. The utility of this chemistry is further demonstrated by the asymmetric synthesis of 3-substituted indanone derivatives 8a, 8d, 8e, and 8i with high enantiomeric excess, which are potential building blocks for preparing biologically active lead compounds.
Ortho-substituted benzofused macrocyclic lactams as zinc metalloprotease inhibitors
Ksander, Gary M.,De Jesus, Reynalda,Yuan, Andrew,Ghai,Trapani,McMartin, Colin,Bohacek, Regine
, p. 495 - 505 (2007/10/03)
The design and preparation of ortho-substituted benzofused macrocyclic lactams are described. The benzofused macrocyclic lactams were designed as neutral endopeptidase 24.11 (NEP) inhibitors. Docking studies were carried out in a model of thermolysin (TLN) using the MACROMODEL and QXP modeling programs to select suitable ring sizes. These studies predicted that the 11- , 12-, and 13-membered ring macrocyclic lactams would be active in both enzymes TLN and NEP. Good predictability of experimental results, within this series, of binding to thermolysin and to a lesser extent to NEP was observed. A visual comparison, docked at the active site of TLN, is presented for thiorphan, a 10-membered ring macrocycle and an 11-membered ring benzofused macrocyclic lactam. Potent inhibition of both NEP and thermolysin was obtained. The 11-membered ring macrocycle 25a is the most potent inhibitor from this series of compounds (TLN IC50 = 68 nM; NEP IC50 = 0.9 nM). The effects of prodrug 44b administered at 10 mg/kg po on plasma atrial natriuretic peptide (ANP) levels in conscious rats was greater than 200% over a 4 h period.
Arachidonic acid analogues, processes for their preparation and their use in medicine
-
, (2008/06/13)
A compound of formula (I): STR1 or a salt thereof, in which Y is a group--O(CH2)m CH2)m CH1 and R2, which may be the same or different, represents hydrogen or C1-6 alkyl, X represents a double or triple bond, and each of A and B represents hydrogen when X is a double bond, or both A and B are absent when X is a triple bond, is useful in treating allergic diseases.
