Effect of high pressure on the composition of stereoisomers of the Diels-Alder reaction between furan and maleic anhydride

Zhulin, V. M.; Bogdanov, V. S.; Kel'tseva, M. V.; Kabotyanskaya, E. B.; Koreshkov, Yu. D.

doi:10.1007/bf01168074

Cited by 7 publications

(3 citation statements)

References 3 publications

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“…The former reaction ( 1 + 2 ) was studied both experimentally − and theoretically. ,, Nevertheless, recent NMR measurements, , supported by correlated quantum chemical calculations, sharply disagree with the earlier results of Lee and Herndon . The new results suggest that the predominant formation of 5 is caused by its higher thermodynamic stability, and only a very small kinetic preference for isomer 4 (the activation barrier is about 0.8 kJ mol -1 higher 22 for isomer 5 ) was determined.…”

Section: Introductionmentioning

confidence: 83%

An Experimental and Theoretical Study of Stereoselectivity of Furan−Maleic Anhydride and Furan−Maleimide Diels−Alder Reactions

et al. 2005

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The stereoselectivity of the reaction of furan (1) with maleic anhydride (2) and maleimide (3) was studied experimentally and theoretically. Although the two reactions are highly similar with regard to their preference for endo and exo steroisomers, notable differences were experimentally observed and explained on the basis of calculated reaction-free energies and transition-state barriers. The experimental values of rate constants (k(1+2endo) = (1.75 +/- 0.48) x 10(-5); mol(-1) l s(-1); k(1+2exo) = (3.10 +/- 0.55) x 10(-5); mol(-1) l s(-1); k(1+3endo) = (1.93 +/- 0.082) x 10(-5); mol(-1) l s(-1), k(1+3exo) = (1.38 +/- 0.055) x 10(-5); mol(-1) l s(-1) all at 300 K) and the observed reaction course clearly confirm that neither of these reactions are prototypical examples of Diels-Alder [4 + 2] cycloadditions, whose dominant preference is for endo isomers. However, only by comparing their energetics-calculated at the CCSD(T) level of theory-with the analogous reactions involving cyclopentadiene (8) as a diene can these observations be understood. The low thermodynamic stability of furan [4 + 2] adducts opens retro-Diels-Alder reaction channels and overrules the very small kinetic preference (calculated and measured here) of initial formation for endo stereoisomers. On a macroscopic scale "an irregular"-thermodynamically more stable-exo stereoisomer was consequently observed as a dominant species.

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Section: Introductionmentioning

confidence: 83%

An Experimental and Theoretical Study of Stereoselectivity of Furan−Maleic Anhydride and Furan−Maleimide Diels−Alder Reactions

et al. 2005

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“…18 However, the reinvestigation into the stereochemical course of this reaction has turned this picture on its head. On one hand, experimental studies have shown that the previously described endo preference was in error, 51,52 with the endo transition state being only slightly favored in comparison with the analogous exo state (0.2 kcal mol -1 ). 26 On the other hand, MP2/6-31G* calculations have indicated that secondary charge transfer between the reactants does not take place.…”

Section: The Furan + Maleic Anhydride Cycloadditionmentioning

confidence: 91%

Do Secondary Orbital Interactions Really Exist?

2000

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A revision of the most typical examples used to illustrate the existence of secondary orbital interactions (SOI) has been achieved. However, our analysis indicates that no conclusive evidence can be obtained from these cases. All five examples proposed by Woodward and Hoffmann in The Conservation of Orbital Symmetry have been revisited. A combination of well-known mechanisms (such as solvent effects, steric interactions, hydrogen bonds, electrostatic forces, and others) can be invoked instead to justify the endo/exo selectivity of Diels-Alder reactions.

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“…In fact, there are very few experimental , and theoretical studies of DA adducts of furan aside from 1 . Compound 1 is the most extensively characterized derivative of 7-oxabicyclo[2.2.1]hept-2-ene, with X-ray structural data and theoretical as well as kinetic and thermodynamic studies at atmospheric , and elevated , pressures reported.…”

Section: Introductionmentioning

confidence: 99%

Retro Diels−Alder Reactions of 5,6-Disubstituted-7-oxabicyclo[2.2.1]hept-2-enes: Experimental and Density Functional Theory Studies

et al. 2000

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Several 5,6-disubstituted-7-oxabicyclo[2.2.1]hept-2-enes (1-4) were synthesized on > or = 0.1 mol scale. The heat-induced retro Diels-Alder (rDA) decomposition of these derivatives was studied by thermal analysis, and the kinetics of the rDA were measured for 4. First-order rate constants (k = 1.91-14.2 x 10(-5) s(-1)), measured at four temperatures between 124 and 150 degrees C, were used to calculate Arrhenius activation parameters Ea (34.5 +/- 0.5 kcal/mol) and ln A (1.77 +/- 0.03 x 10(4)). The observed activation energy was significantly larger (by 9.5 kcal/mol) than that previously measured for the maleic anhydride adduct 1, and this was attributed to the difference in LUMO energies for the two dienophiles. Modeling of the activation parameters found for 4 with density functional theory (DFT) calculations for similar compounds 5 and 6 gave close quantitative correlations for deltaH double dagger, deltaG double dagger, deltaS double dagger. The rDA reactions studied were found to be entropy-driven.

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Effect of high pressure on the composition of stereoisomers of the Diels-Alder reaction between furan and maleic anhydride

Cited by 7 publications

References 3 publications

An Experimental and Theoretical Study of Stereoselectivity of Furan−Maleic Anhydride and Furan−Maleimide Diels−Alder Reactions

An Experimental and Theoretical Study of Stereoselectivity of Furan−Maleic Anhydride and Furan−Maleimide Diels−Alder Reactions

Do Secondary Orbital Interactions Really Exist?

Retro Diels−Alder Reactions of 5,6-Disubstituted-7-oxabicyclo[2.2.1]hept-2-enes: Experimental and Density Functional Theory Studies

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