0000000000349750
AUTHOR
Aicha Derdour
A combined experimental and theoretical study of the polar [3+2] cycloaddition of electrophilically activated carbonyl ylides with aldehydes and imines
International audience; Numerous 2,5-diaryl-1,3-dioxolane-4,4-dicarbonitriles and 2,4-diphenyl-1,3-oxazolidine-5,5- dicarbonitriles have been synthesized by [3+2] cycloaddition reactions between carbonyl ylides generated from epoxides, and aldehydes or imines. In contrast to the use of aldehydes (3,4,5- trimethoxybenzaldehyde, piperonal, 1-naphthaldehyde, indole-3-carboxaldehyde, furan-2- carboxaldehyde and thiophene-2-carboxaldehyde), the reactions performed with imines (N- (phenylmethylene)methanamine, N-(1,3-benzodioxol-5-ylmethylene)propylamine, N-(1,3-benzodioxol- 5-ylmethylene)butylamine and N-(1,3-benzodioxol-5-ylmethylene)benzylamine) proceed diastereoselectively. The effect of micr…
Experimental and theoretical study of the [3+2] cycloaddition of carbonyl ylides with alkynes
[EN] The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and alkynes (phenylacetylene, methyl propiolate, methyl but-2-ynoate and methyl 3-phenylpropiolate) to give substituted 2,5-dihydrofurans was investigated. The effect of indium(III) chloride on the outcome of the reaction was studied in the case of phenylacetylene and methyl propiolate. The thermal reaction between the carbonyl ylide coming from 2,2-dicyano-3-phenyloxirane and both methyl propiolate and methyl but-2-ynoate was theoretically investigated using DFT methods in order to explain the reactivity and regioselectivity observed.
Polar [3 + 2] cycloaddition of ketones with electrophilically activated carbonyl ylides. Synthesis of spirocyclic dioxolane indolinones
International audience; The [3 + 2] cycloaddition reaction between carbonyl ylides generated from epoxides and ketones (ethyl pyruvate, ethyl phenylglyoxylate, isatin, N-methylisatin and 5-chloroisatin) to give substituted dioxolanes and spirocyclic dioxolane indolinones was investigated. The effect of microwave irradiation on the outcome of the reaction was studied. The thermal reaction between 2,2-dicyano-3-phenyloxirane and N-methylisatin was theoretically studied using DFT methods. This reaction is a domino process that comprises two steps. The first is the thermal ring opening of the epoxide to yield a carbonyl ylide intermediate, whereas the second step is a polar [3 + 2] cycloadditio…
A combined experimental and theoretical study of the thermal cycloaddition of aryl azides with activated alkenes.
International audience; Reactions were performed from aryl azides on the one hand, and activated alkenes coming from β-dicarbonyl compounds or malonodinitrile on the other hand, either with recourse to conventional heating or to microwave activation, to afford 1-aryl-1H-1,2,3-triazoles. The mechanism and the regioselectivity of the reactions involving β-dicarbonyl compounds have been theoretically studied using DFT methods at the B3LYP/6-31G* level: they are domino processes comprising a tautomeric equilibrium of the β-dicarbonyl compounds with their enol forms, a 1,3-dipolar cycloaddition of the enol forms with the aryl azides (high activation energy), and a dehydration process (lower acti…