742-97-2Relevant academic research and scientific papers
Ionic liquid as catalyst and solvent: the remarkable effect of a basic ionic liquid, [bmIm]OH on Michael addition and alkylation of active methylene compounds
Ranu, Brindaban C.,Banerjee, Subhash,Jana, Ranjan
, p. 776 - 782 (2007/10/03)
A basic ionic liquid, 1-methyl-3-butylimidazolium hydroxide, [bmIm]OH, catalyzes the Michael addition of active methylene compounds to conjugated ketones, carboxylic esters and nitriles. It further catalyzes the addition of thiols to α,β-acetylenic ketones and alkylation of 1,3-dicarbonyl and -dicyano compounds. The Michael addition to α,β-unsaturated ketones proceeds in the usual way, giving the monoaddition products, whereas addition to α,β-unsaturated esters and nitriles leads exclusively to the bis-addition products. The α,β-acetylenic ketones undergo double conjugate addition with thiols producing β-keto 1,3-dithio-derivatives. In the alkylation reaction the acyclic 1,3-diketones are monoalkylated, whereas cyclic ketones undergo dialkylation under identical conditions. All these reactions were carried out without any organic solvent. The ionic liquid can also be recycled.
CHEMIOSELECTIVITY IN THE PRESENCE OF SURFACTANTS. I. C- vs. O-ALKYLATION IN β-DICARBONYL COMPOUNDS
Bassetti, Mauro,Cerichelli, Giorgio,Floris, Barbara
, p. 583 - 586 (2007/10/02)
A number of β-dicarbonyl compounds (2,4-pentanedione, 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclopentanedione, ethyl 3-oxobutanoate, and diethyl propanedioate) reacted with benzyl bromide in basic aqueous solutions of hexadecyltrimethylammonium bromide at room temperature.The presence of the cationic surfactant directed the reaction toward the carbon nucleophilic site, with high chemioselectivity.C-Dialkylated species were generally predominant, due to the increased lipophilicity of the monoalkylated species, with respect to the reagent.No hydrolysis of benzyl bromide was observed in the presence of the surfactant.
