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Synthesis of the Potential Mannosidase Inhibitor via 1,3-Dipolar Cycloaddition Involving Cyclic Nitrone and Unsaturated Chiral gamma-Lactone

Stecko S., Paśniczek , K., Jurczak M., Solecka J., Chmielewski M.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 2

237-243

EN

The 1,3-dipolar cycloaddition of cyclic nitrone derived from tartaric acid with (S)-5-hydroxymethyl-2(5H)-furanone leads to a single adduct which was transformed into 1,2,6,7-tetrahydroxy-2-hydroxymethyl-indolizidine via reaction sequence involving protection of the hydroxymethyl group, reduction of the lactone moiety, protection of the resulting diol, and the N-O hydrogenolysis followed by the intramolecular alkylation of the nitrogen atom.

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Synthesis and Properties of Azoles and Their Derivatives. Part LXII. Secondary Deuterium Kinetic Isotope Effects in [2+3] Cycloaddition of (E)-2-Phenylnitroethene to (Z)-C,N-Diphenylnitrone

Barański A., Lyubimtsev A., Jasiński R., Kwiatkowska M.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 5

1037-1042

EN

SKIE analysis of [2+3] cycloaddition of (E)-2-phenylnitroethene to (Z)-C,N-diphenyl - nitrone suggests that for both stereoisomeric reaction paths (Scheme 1), the O1-C5 bond of the adduct forms faster than the corresponding C3-C4 bond. Never the less, both stereo isomers are formed by an one-step mechanism. According to Hammond's terminology, the transition states in volved in the reaction mechanism can be classified as asynchronous early states.

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Synthesis and Properties of Azoles and Their Derivatives. Part LXIV. [2+3] Cycloaddition of trans-1-Nitropropene-1 to C,C,N-Triphenylnitrone in the Light of AM1/COSMO Calculations

Jasiński R., Barański A.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 5

1043-1049

EN

Quantum-chemical simulations of [2+3] cycloaddition of trans-1-nitropropene with triphenylnitrone in nitromethane and formamide have been carried out using AM1/COSMO algorithm. The results suggest that the reaction leading to 2,3,3- tri - phenyl-4-methyl-5-nitroisoxazolidine occurs by a concerted mechanism, while the alternative reaction leading to regioisomeric 2,3,3-triphenyl-4-ni tro-5- methyl isoxazolidine occurs by anionic mechanism.

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Synthesis and Properties of Azoles and Their Derivatives. Part LXV*. Kinetic Study on the [2+3] Cycloaddition of Triphenylnitrone to trans-1-Nitroprop-1-ene

Jasiński R., Barański A.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 11

2125-2131

EN

The [2+3] cycloaddition of triphenylnitrone to trans-1-nitroprop-1-ene proceeds according to concerted mechanism, in spite of pi-deficient character of dipolarophile and strongly shielded one of the reaction centers in molecule of 1,3-dipole. This mechanism is indicated by the obtained values of activation parameters and weak kinetic solvent effect.

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Synthesis and Properties of Azoles and Their Derivatives. Part LVIII. DFT Study on [2+3] Cycloaddition of trans-Nitroethenes to Z-C,N-Diphenylnitrone

Jasiński R., Barański A.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 8

1441-1447

EN

DFT calculations indicate that the transition states of [2+3] cycloaddition of trans-2- phenylnitroethene to Z-C,N-diphenylnitrone led to 3,4-cis and 3,4-trans 4-nitroisoxazolidines are almost perfectly symmetrical. Asymmetry of the transition states appears for the reaction with more -deficient trans-2-(trichloromethyl)-nitroethene. Nevertheless, in both cases the formation of azolidine rings occurs in one step. The calculational results correlate well with experimental data.

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Synthesis and Properties of Azoles and Their Derivatives. Part LVI. Mechanistic Aspects on the [2+3] Cycloaddition of Z-C,N-Diphenylnitrone with trans-1-Nitropropene-1 and trans-3,3,3-Trichloro-1-nitropropene-1

Jasiński R., Barański A.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 9

1493-1502

EN

The [2+3] cycloaddition reactions of diphenylnitrone with trans-1-nitropropene-1 and trans-3,3,3-trichloro-1-nitropropene-1 occur via a concerted mechanism despite high -deficient character of dipolarophiles. This mechanism is indicated by cis-stereospecificity of the cycloaddition, the obtained values of activation parameters and weak solvent effect on the reaction kinetics.

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Synthesis and Properties of Azoles and Their Derivatives. Part LV*. Mechanism of c,C,N-Triphenylnitrone [2+3]-Cycloaddition with (E)-3,3,3-Trichloro-1-nitropropene-1 in the Light of AM1 and AM1/COSMO Calculations

Jasiński R., Brandel E., Barański A.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 1

83-88

EN

AM1 calculations suggest that the [2+3]-cycloaddition of C,C,N-triphenylnitrone (1) to (E)-3,3,3-trichloro-1-nitropropene-1 (2) in gas phase occurs in concerted manner. Kinetic factors favour the formation of cycloadduct with nitrogen group in position C4 of the isoxazolidine ring (path A). Introduction of toluene as a dielectric medium does not alter this preferable. However, the character of the energy profile for path A undergoes a critical change. In this case, two transition states and intermediate with zwitterionic character were localized by means of AM1/COSMO method.