Catalyst-Free Conjugated Addition of Thiols to α,β-Unsaturated Carbonyl Compounds in Water
作者:Gopal L. Khatik、Raj Kumar、Asit K. Chakraborti
DOI:10.1021/ol060846t
日期:2006.5.1
[reaction: see text] Catalyst-free conjugateaddition of thiols to alpha,beta-unsaturated carbonylcompounds in water is reported. beta-Sulfido carbonylcompounds were formed at room temperature, in short times and with excellent chemoselectivity. Competitive dithiane/dithiolane formation, transesterification, and ester cleavage were not observed. Water played a dual role in simultaneously activating
Acidic-functionalized ionic liquid as an efficient, green and reusable catalyst for hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones
作者:Feng Han、Lei Yang、Zhen Li、Chungu Xia
DOI:10.1039/c1ob06346d
日期:——
A series of acidic-functionalized ionic liquids were synthesized and applied to the hetero-Michael addition of nitrogen, sulfur and oxygen nucleophiles to α,β-unsaturated ketones under solvent-free conditions. Notably, 1-methylimidazoliump-toluenesulfonic ([Hmim]OTs) was found to be the most efficient catalyst and could realize âhomogeneous catalysis, two-phase separationâ. Additionally, the catalytic system has wide substrate scope and good to excellent yields (up to 99%) could be obtained at room temperature.
Synthesis and application of modified silica sulfuric acid as a solid acid heterogeneous catalyst in Michael addition reactions
作者:Mohammad Ali Zolfigol、Hojat Veisi、Farajollah Mohanazadeh、Alireza Sedrpoushan
DOI:10.1002/jhet.659
日期:2011.7
Modified silicasulfuricacid (MSSA) as a new type of silicasulfuricacid was prepared and effectively used in the conjugate addition of indole, pyrrole, and thiols with Michael acceptors under mild conditions at room temperature. Also, MSSA was used as a catalyst for the synthesis of 1,1,3‐tri‐indolyl compounds in good to excellent yield at room temperature. J. Heterocyclic Chem., (2011).
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.
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