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.
Potassium phosphate or silica sulfuric acid catalyzed conjugate addition of thiols to α,β-unsaturated ketones at room temperature under solvent-free conditions
sulfuric acid have been found to be useful and highly efficient catalysts for conjugateaddition of thiols to α,β-unsaturated ketones undersolvent-freeconditions, at room temperature. Silica sulfuric acid (SSA) was found to be suitable for electron-deficient enones while potassium phosphate was found to effect thia-Michael addition with both, electron-deficient as well as electron-rich conjugated ketones
A Simple, Efficient, and Green Procedure for the 1,4-Addition of Thiols to Conjugated Alkenes and Alkynes Catalyzed by Sodium Acetate in Aqueous Medium
作者:Brindaban C. Ranu、Tanmay Mandal
DOI:10.1071/ch06455
日期:——
A benign and inexpensive salt, sodium acetate, efficiently catalyzes 1,4-addition of thiols to a variety of conjugated alkenes such as α,β-unsaturatedketones, aldehydes, carboxylic esters, nitriles, nitro compounds, and chalcones in aqueous THF. The reactions are clean, fast, and high yielding.
Indium(I) Iodide-Promoted Cleavage of Dialkyl Disulfides and Subsequent Michael Addition of Thiolate Anions to Conjugated Carbonyl Compounds
作者:Brindaban C. Ranu、Tanmay Mandal
DOI:10.1055/s-2004-825583
日期:——
Indium(I) iodide promotes cleavage of dialkyl disulfides generating thiolate anions which then undergo facile addition to α, β -unsaturated ketones, aldehydes, carboxylic esters and nitriles under neutral conditions producing corresponding β-keto or β-cyano sulfides in high yields. There are several examples of dialkyl/diaryl disulfides and activated alkenes participating in this reaction.
E-factor minimized protocols for the polystyryl-BEMP catalyzed conjugate additions of various nucleophiles to α,β-unsaturated carbonyl compounds
作者:Simona Bonollo、Daniela Lanari、Julie M. Longo、Luigi Vaccaro
DOI:10.1039/c1gc16088e
日期:——
Efficient protocols for the addition of carbon-, sulphur- and nitrogen-nucleophiles to α,β-unsaturated carbonylcompounds catalyzed by PS-BEMP have been reported. The adoption of solvent-free conditions (SolFC) was crucial for improving the efficiency of all the processes, while by using an organic reaction medium poor results were obtained. Addition reactions were performed by using equimolar amounts