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.
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.
Bioinspired Catalytic Conjugate Additions of Thiophenols to α,β-Enones by a Disubstituted Benzoate-Bridged Nickel Mimic for the Active Site of Urease
作者:Way-Zen Lee、Huan-Sheng Tseng、Tzu-Li Wang、Hui-Lien Tsai、Ting-Shen Kuo
DOI:10.1021/om100103u
日期:2010.7.12
te (HL), was prepared to synthesize nickel mimics for the active site of urease. Reaction of the deprotonated L− with Ni(ClO4)2·6H2O afforded a dinickelcomplex, [LNi2(CH3CN)(THF)](ClO4)3 (1), characterized by UV/vis spectroscopy and X-ray crystallography. Addition of urea to an acetonitrile solution of 1 afforded a dinickel urea adduct, [LNi2(urea)2](ClO4)3·2CH3CN (2), which was structurally and spectroscopically
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.