Indium(I) iodide promoted cleavage of dialkyl disulfides — Application of the Michael addition of thiolate anions to conjugated carbonyl compounds and regioselective ring opening of epoxides

2006 ◽  
Vol 84 (5) ◽  
pp. 762-770 ◽  
Author(s):  
Brindaban C Ranu ◽  
Tanmay Mandal
Keyword(s):  
Michael Addition ◽  
Ring Opening ◽  
Unsaturated Ketones ◽  
Ring Opening Of Epoxides ◽  
Dialkyl Disulfides ◽  
Carboxylic Esters ◽  
Thiolate Anions ◽  
Neutral Conditions ◽  
Nucleophilic Ring Opening ◽  
The Michael Addition

Indium(I) iodide promotes cleavage of dialkyl disulfides generating thiolate anions that then undergo facile addition to α,β-unsaturated ketones, aldehydes, carboxylic esters, and nitriles under neutral conditions producing corresponding β-ketosulfides or β-cyanosulfides. This strategy has also been used for the regioselective nucleophilic ring opening of epoxides by thiolate anions in presence of indium(III) chloride producing corresponding β-hydroxyphenyl sulfides. The reactions are in general, very clean, high yielding, and reasonably fast. Thus, simple and convenient procedures for the synthesis of β-ketosulfides or β-cyanosulfides and β-hydroxyalkyl sulfides have been developed using this cleavage reaction.Key words: indium(I) iodide, Michael addition, β-ketosulfide, β-cyanosulfide, epoxide, β-hydroxy sulfide.

Solid lithium perchlorate as a powerful catalyst for the synthesis of β-aminoalcohols under solvent-free conditions

2005 ◽  
Vol 83 (5) ◽  
pp. 505-507 ◽  
Author(s):  
Najmodin Azizi ◽  
Mohammad R Saidi
Keyword(s):  
Ring Opening ◽  
Room Temperature ◽  
Lithium Perchlorate ◽  
Solvent Free ◽  
Solvent Free Conditions ◽  
Reaction Proceeds ◽  
Ring Opening Of Epoxides ◽  
Neutral Conditions ◽  
Hindered Amines ◽  
Short Times

Lithium perchlorate catalyzed the ring opening of epoxides with amines to provide the corresponding β-aminoalcohols in excellent yields with high regioselectivity. The reaction proceeds rapidly under mild and neutral conditions and worked well with primary, secondary, aliphatic, aromatic, and hindered amines in short times at room temperature, in the absence of solvent.Key words: epoxide, lithium perchlorate, β-aminoalcohols, solvent-free.

CARCINOGENICITY OF LACTONES: I. THE REACTION OF 4-METHYLBUTENO- AND 4-METHYLBUTANO-γ-LACTONES WITH PRIMARY AMINES

1966 ◽  
Vol 44 (9) ◽  
pp. 1059-1068 ◽  
Author(s):  
J. Bryan Jones ◽  
John M. Young
Keyword(s):  
Magnetic Resonance ◽  
Michael Addition ◽  
Ring Opening ◽  
Proton Magnetic Resonance ◽  
Mechanisms Of Action ◽  
Reaction Pathways ◽  
Nucleophilic Attack ◽  
Primary Amines ◽  
Acid Lactone ◽  
The Michael Addition

As the first stage in the investigations of the mechanisms of action of carcinogenic lactones, the reactions of 4-hydroxypent-2-enoic acid lactone (II, R = CH3), which is a carcinogen, and of the non-carcinogenic 4-hydroxypent-3-enoic (III, R = CH3) and 4-hydroxypentanoic (IV, R = CH3) acid lactones with methylamine and benzylamine have been studied. As expected, the carcinogenic lactone reacts to give the Michael addition products, whereas both inactive lactones undergo ring opening by nucleophilic attack at the carbonyl group. From the relative rates of reaction of the amines with the lactones it is concluded that the induction of tumors by II (R = CH3) does not involve alkylation of biological primary alkylamino groups. The proton magnetic resonance spectra of the products enable the different reaction pathways to be distinguished readily, and may provide the basis for rapid physicochemical screening of alkylation agents that are potential carcinogens.

On the Stereoselectivity of the (-)-Dimenthyl Malonate Addition to α,β-Unsaturated Ketones

1996 ◽  
Vol 61 (12) ◽  
pp. 1805-1814 ◽  
Author(s):  
Ľubomír Šebo ◽  
Juraj Alföldi ◽  
Grety Rihs ◽  
Štefan Toma
Keyword(s):  
Michael Addition ◽  
Pure State ◽  
Nmr Spectra ◽  
Reaction Products ◽  
X Ray ◽  
Unsaturated Ketones ◽  
H Nmr ◽  
The Michael Addition

The Michael addition of (-)-dimenthyl malonate to eight α,β-unsaturated ketones has been studied. The ratio of diastereomers was calculated on the basis of the 1H NMR spectra of the crude reaction products. The diastereomer excess varied from 10 to 50%, depending on the structure of the starting enone. The pure diastereomer produced by addition of (-)-dimenthyl malonate to 2-benzylidene-1,4-indandione was isolated by repeated crystallization. X-ray analysis has shown that the isomer is (-)-dimenthyl (R)-2-[1-(1,3-dioxoindan-2-yl)-1-phenylmethyl]malonate (5a). The predominating diastereomers of (-)-dimenthyl(3-ferrocenyl-3-oxophenylpropyl)malonate (1a) and (-)-dimenthyl-2-(1-(1,3-dioxo[3]ferrocenophan-2-yl)-1-phenyl malonate (6a) were also isolated in pure state by careful crystallization.

Ionic-liquid-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene — An efficient and recyclable organocatalyst for Michael addition to α,β-unsaturated ketones

2012 ◽  
Vol 90 (3) ◽  
pp. 290-297 ◽  
Author(s):  
Manoj Kumar Muthyala ◽  
Bhupender S Chhikara ◽  
Keykavous Parang ◽  
Anil Kumar
Keyword(s):  
Ionic Liquid ◽  
Michael Addition ◽  
Room Temperature ◽  
Significant Loss ◽  
Unsaturated Ketones ◽  
Ability To Act ◽  
Solvent Free Conditions ◽  
Active Methylene Compounds ◽  
Active Methylene ◽  
The Michael Addition

A novel ionic-liquid-supported 1,5,7-triazabicyclo[4.4.0]dec-5-ene (IL–TBD) was synthesized and investigated for its ability to act as an active organocatalyst in the Michael addition of active methylene compounds and thiophenols to chalcones under solvent-free conditions. The IL–TBD afforded Michael addition products in excellent yields (82%–94%) at room temperature, and it was simply recycled and reused at least five times without significant loss of catalytic activity.

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