Squaric acid as an impressive organocatalyst for Michael addition in water
作者:Najmadin Azizi、Elham Saki、Mahtab Edrisi
DOI:10.1016/j.crci.2011.07.003
日期:2011.11
Résumé A simple, green, and environmentally benign protocol for squaric acid (5 mg) catalyst conjugate addition of aromatic amines and thiols to unsaturated carbonyl compounds in water in good to excellent yields is developed. The advantages of low sensitivity toward moisture and oxygen, high tolerance of different functional groups, green reaction media and efficient recyclability make this organocatalyst suitable for both laboratory and industrial scale synthesis of β-substituted carbonyls under very mild conditions.
Fluoroboric acid adsorbed on silica-gel (HBF4–SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds
作者:Gaurav Sharma、Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tetlet.2008.04.144
日期:2008.6
found to be a new and highly efficient heterogeneouscatalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of 1,3-diaryl-2-propenones, the reactions are best carried out in MeOH. The rate of thia-Michael addition was dependent on the steric hindrance at the β-carbon of the α,β-unsaturated carbonyl substrate as well as surrounding the thiol
Synthesis of Biphenyl-Based Ligand: Application in Copper-Mediated Chemoselective Michael Reaction
作者:M. Shyam Sundar、Ashutosh V. Bedekar
DOI:10.1080/00397911.2014.946996
日期:2014.12.17
Abstract A biphenyl-based ligand attached was synthesized and screened in copper-mediated Michael reaction. The catalyst system works well with carbon or sulfur nucleophiles as Michael donors and cyclohexenone or chalcones as the acceptors under mild and neutral reaction conditions in a chemoselective manner. GRAPHICAL ABSTRACT