Scope and limitations of HClO4–SiO2 as an extremely efficient, inexpensive, and reusable catalyst for chemoselective carbon–sulfur bond formation
作者:Gopal L. Khatik、Gaurav Sharma、Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tet.2006.11.050
日期:2007.1
cyclic and acyclic α,β-unsaturatedketones afforded excellent yields of the corresponding β-sulfidocarbonyls after 2 min to 2 h. In the case of dithiols, the bis-thia-Michael adducts were formed. The rate of the reaction was found to be dependent on the electronic and steric factors of the α,β-unsaturatedketones and the thiols. A substituent at the β-carbon of the α,β-unsaturatedketone offered steric
Natural Phosphate Modified with Lithium Nitrate: A New Efficient Catalyst for the Construction of Carbon–Carbon, Carbon–Sulfur, and Carbon–Nitrogen Bonds
of small amounts of lithium nitrate to natural phosphate followed by calcination gives a new catalyst Li/NP (weight ratio LiNO3/NP = 1/15). This material showed catalytic activity in the Michael addition of amines, mercaptans, and activemethylenecompounds to chalcone derivatives with high yields under mild reaction conditions. Li/NP is used as the catalyst for a facile synthesis of β-amino acids,
Animal Bone Meal (ABM): A Novel Natural Catalyst for Thia-Michael Addition
作者:Yassine Riadi、Rachid Mamouni、Younes Abrouki、Mohammadine El Haddad、Nabil Saffaj、Said El Antri、Sylvain Routier、Gerald Guillaumet、Said Lazar
DOI:10.2174/157017810791112397
日期:2010.4.1
The preparation and use of Animal Bone Meal (ABM) as natural catalyst is described for C-S bond formation by thia-Michael addition. This new natural heterogeneous method led to β-sulfinyl adducts in very high yields after only a few minutes. Influence of the thiol derivatives and substitution on chalcones is discussed.
The objective was to obtain new scaffold of compounds possessing anti-urease activity. For this new and simple method for the synthesis of β-aryl-β-mercapto ketone derivatives based on Michael addition of thiophenol to chalcones in an ionic liquid as a solvent was improved. The products were obtained in good to moderate yields with high purity and characterized by spectral and elemental analyses. The activities of synthesized compounds were investigated as new inhibitors of jack bean urease. Among 22 synthesized compounds, all of them have shown inhibitory effect in micromolar range, and the most potent one has IC50 = 6 μM compared to hydroxyurea IC50 = 100 μM as a reference inhibitor. A docking study was performed using Autodock 4.2 in parallel to in vitro experiments to illustrate the corresponded binding affinities as well as binding site, and involved residues in interaction. These computational results complimented the experimental inhibition activity and enabled us to report a potent urease inhibitors based on β-aryl-β-mercapto ketone scaffold.
Fluorapatite: efficient catalyst for the Michael addition
作者:Mohamed Zahouily、Younes Abrouki、Ahmed Rayadh、Saı̈d Sebti、Hamid Dhimane、Marc David
DOI:10.1016/s0040-4039(03)00323-x
日期:2003.3
A Michael addition assisted by fluorapatite in heterogeneous media is described. Reaction between mercaptans and chalcone derivatives was studied at room temperature in methanol as solvent. By-products of usual undesirable reactions in Michael addition such as 1,2-addition, bis-addition and polymerisation are not observed. The yields obtained are good to excellent. (C) 2003 Elsevier Science Ltd. All rights reserved.