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Norbornadiene
About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.
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TL;DR: In this paper, the authors presented the first density functional theory benchmark study of a NBD/QC derivative in vacuum with respect to novel gas-phase experiments, and they found that the M06-2X/def2-TZVP and M06 -2x/6-311+G(d) level of theories produced the most accurate results in terms of maximum absorption wavelength and energy density.
4 citations
TL;DR: In this article, the enthalpies of formation of norbornadiene and other alkenes were calculated using semi-empirical programs MNDO, AM1, and PM3 and the empirical force field method MMP2.
Abstract: The enthalpies of formation of norbornadiene, norbornene, norbornane, nortricyclane, and quadricyclane, which are experimentally known, have been calculated using the semiempirical programs MNDO, AM1, and PM3 and the empirical force-field method MMP2. MMP2 agrees most closely with experimental results. Of the semiempirical methods, PM3 agrees most closely with experimental results and is very good for the alkenes. Enthalpies of hydrogenation, calculable fromΔH
f, are inconclusive on the question of ground-state homoaromatic stabilization of norbornadiene.
4 citations
4 citations
TL;DR: In this article, the site-, regio-, and stereo selectivities of the title reactions have been studied using density functional theory at the M06/6-311G(d,p) level of theory.
Abstract: The site-, regio-, and stereo-selectivities of the title reactions have been studied using density functional theory (DFT) at the M06/6-311G(d,p) level of theory. The effects of substituents on both the three-atom component (TAC) and norbornadiene derivatives have been investigated with a focus on the site-selectivity. The reaction of benzylazide with (1S,4R)-2-tosyl-7-oxabicyclo[2.2.1]hepta-2,5-diene and (1R,4S)-2-bromo-3-tosyl-7-oxabicyclo[2.2.1]hepta-2,5-diene proceeds via addition across the substituted olefinic bond of the two norbornadiene derivatives. Substituents on the TAC do not affect the selectivity of the reaction while substituents on the norbornadiene significantly affect the selectivity of the reaction. Benzylazide preferentially adds across the substituted olefinic bond of the norbornadiene derivative when strong electron-withdrawing group (EWGs) and electron-releasing group (ERGs) substituents are on the norbornadiene while weak ERGs and EWGs on the norbornadiene significantly decreases the site-selectivity such that addition across either double is no longer favored over the other. The formation of exo-cycloadducts is generally favored over the endo-cycloadducts. The reaction of benzylazide and norbornadiene derivatives is a highly irreversible exergonic reaction. The direction of electron density flux is dependent on the nature of the substituent on the reactants. Global reactivity indices and Parr function calculations are in good agreement with the activation barriers and the selectivity of the reactions.
4 citations