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.
Synthesis of β-sulfanyl ketones via a tandem rearrangement-conjugate addition reaction catalyzed by a Re(V)-oxo complex
作者:Alyson E. Garst、Alexandra D. Badiceanu、Kristine A. Nolin
DOI:10.1016/j.tetlet.2012.11.047
日期:2013.2
A method for synthesizing β-sulfanyl ketones via a tandem rearrangement and conjugate addition reaction has been developed. This methodology provides access to a range of β-sulfanyl ketones through the rearrangement of propargyl alcohols to the corresponding enones followed by the conjugate addition of unactivated thiols. The one-pot, tandem transformation is catalyzed by ReOCl3(OPPh3)(S(CH3)2) affording
JandaJel as a polymeric support to improve the catalytic efficiency of immobilized-1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) under solvent-free conditions
JandaJel, with its greater spacing between the linear polymeric chains compared to that of polystyrene matrices, is a very efficient support for improving the catalytic efficiency of TBD under SolFC.
Conjugate addition of unactivated thiols to α,β-unsaturated ketones catalyzed by a bifunctional rhenium(V)–oxo complex
作者:Allan Peng、Ross Rosenblatt、Kristine Nolin
DOI:10.1016/j.tetlet.2012.03.075
日期:2012.5
found to be an efficient bifunctional catalyst for the 1,4-addition of thiols to α,β-unsaturatedketones. The addition of thiophenol derivatives and alkyl thiols proceeds under mild reaction conditions without pre-activation of the thiol or exogenous base. Reactions of aryl, alkyl, and cyclic enones produce the corresponding β-sulfanyl ketones in good to excellent yield.
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