Diastereomers of a cofacial ternaphthalene and two azaternaphthalenes. Syntheses and barriers to isomerization

Zoltewicz, John A.; Maier, Norbert M.; Lavieri, Sophie; Ghiviriga, Ion; Abboud, Khalil A.; Fabian, Walter M. F.

doi:10.1016/s0040-4020(97)00232-9

Cited by 30 publications

(48 citation statements)

References 24 publications

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“…Finally, we succeeded in the determination of the anti/syn ratio for compound 14, bearing two cofacial 1-naphthyl units (entry 6). As previously described, [15] in comparison with compound 4 the presence of bulky naphthyl rings did not significantly affect the anti/syn ratio (entry 6). The 82:18 anti/syn ratio calculated from the 1 H NMR spectra may result from a compromise between an overall increase in the bulk of the cofacial rings and a decrease in the hybridization order from an sp 3 -C (methyl in 4) to an sp 2 -C (aromatic in 14).…”

Section: Structures In Solutionsupporting

confidence: 69%

Synthesis and Molecular Structure of Symmetrical 1,8‐Diarylnaphthalenes

Pieters¹,

Terrasson²,

Gaucher³

et al. 2010

Eur J Org Chem

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The synthesis of substituted 1,8‐diarylnaphthalenes is reported. A bis‐Suzuki coupling strategy starting from 1,8‐dibromonaphthalene provides a useful and general route to the 1,8‐diarylnaphthalene scaffold. In this context, N‐heterocyclic benzhydrylamine ligands, in combination with PdCl2, were found to form especially efficient catalytic systems. The syn/anti ratios were determined in solution from their 1H NMR spectra. Analysis of the molecular structure in the solid state for six new targets focused on deformation of the naphthalene core. The observed lack of planarity occurs as a result of several parameters, such as the nature and number of substituents, the substitution pattern as well as steric congestion and π‐stacking between cofacial rings.

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Section: Structures In Solutionsupporting

confidence: 69%

Synthesis and Molecular Structure of Symmetrical 1,8‐Diarylnaphthalenes

Pieters¹,

Terrasson²,

Gaucher³

et al. 2010

Eur J Org Chem

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“…Isoquinoline‐5‐carboxaldehyde and the precursor for monoradical 10 , 5‐nitroisoquinoline, were purchased from Sigma–Aldrich and used without further purification. The precursor for monoradical 9 , 4‐iodoisoquinoline, was synthesized by a known method 20. The precursor for biradical 8 , 4‐iodo‐5‐nitroisoquinoline, was synthesized for the first time by using the reaction conditions described by Grubbs et al 21.…”

Section: Methodsmentioning

confidence: 99%

“…The precursor for monoradical 9, 4-iodoisoquinoline, was synthesized by a known method. [20] The precursor for biradical 8, 4-iodo-5-nitroisoquinoline, was synthesized for the first time by using the reaction conditions described by Grubbs et al [21] for 4-iodoisoquinoline. The structure was verified by x-ray crystallography.…”

Section: Methodsmentioning

confidence: 99%

Reactivity of the 4,5‐Didehydroisoquinolinium Cation

Vinueza¹,

Archibold²,

Jankiewicz³

et al. 2012

Chemistry A European J

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The chemical properties of a 1,8-didehydronaphthalene derivative, the 4,5-didehydroisoquinolinium cation, were examined in the gas phase in a dual-cell Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. This is an interesting biradical because it has two radical sites in close proximity, yet their coupling is very weak. In fact, the biradical is calculated to have approximately degenerate singlet and triplet states. This biradical was found to exclusively undergo radical reactions, as opposed to other related biradicals with nearby radical sites. The first bond formation occurs at the radical site in the 4-position, followed by that in the 5-position. The proximity of the radical sites leads to reactions that have not been observed for related mono- or biradicals. Interestingly, some ortho-benzynes have been found to yield similar products. Since ortho-benzynes do not react via radical mechanisms, these products must be especially favorable thermodynamically.

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“…The precursor for monoradical 1,4 -iodoisoquinoline, was synthesized according to ap rocedure reported in the literature. [30] The precursor for monoradical 2,5 -nitroisoquinoline, was obtained from Sigma-Aldrich and used as received. The precursor for monoradical 3,8 -iodoisoquinoline, was synthesized by dissolving 8-aminoisoquinoline (0.5 g, 3.36 mmol;C arbocore) in ac old solution (ice-salt bath) of concentrated HCl (3 mL) and H 2 O( 3mL), and then slowly adding as olution of NaNO 2 (0.28 g, 4.03 mmol) in H 2 O (2 mL).…”

Section: Methodsmentioning

confidence: 99%

Reactivity Controlling Factors for an Aromatic Carbon‐Centered σ,σ,σ‐Triradical: The 4,5,8‐Tridehydroisoquinolinium Ion

Vinueza

Jankiewicz

Gallardo

et al. 2015

Chemistry A European J

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The chemical properties of the 4,5,8-tridehydroisoquinolinium ion (doublet ground state) and related mono- and biradicals were examined in the gas phase in a dual-cell Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometer. The triradical abstracted three hydrogen atoms in a consecutive manner from tetrahydrofuran (THF) and cyclohexane molecules; this demonstrates the presence of three reactive radical sites in this molecule. The high (calculated) electron affinity (EA=6.06 eV) at the radical sites makes the triradical more reactive than two related monoradicals, the 5- and 8-dehydroisoquinolinium ions (EA=4.87 and 5.06 eV, respectively), the reactivity of which is controlled predominantly by polar effects. Calculated triradical stabilization energies predict that the most reactive radical site in the triradical is not position C4, as expected based on the high EA of this radical site, but instead position C5. The latter radical site actually destabilizes the 4,8-biradical moiety, which is singlet coupled. Indeed, experimental reactivity studies show that the radical site at C5 reacts first. This explains why the triradical is not more reactive than the 4-dehydroisoquinolinium ion because the C5 site is the intrinsically least reactive of the three radical sites due to its low EA. Although both EA and spin-spin coupling play major roles in controlling the overall reactivity of the triradical, spin-spin coupling determines the relative reactivity of the three radical sites.

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Diastereomers of a cofacial ternaphthalene and two azaternaphthalenes. Syntheses and barriers to isomerization

Cited by 30 publications

References 24 publications

Synthesis and Molecular Structure of Symmetrical 1,8‐Diarylnaphthalenes

Synthesis and Molecular Structure of Symmetrical 1,8‐Diarylnaphthalenes

Reactivity of the 4,5‐Didehydroisoquinolinium Cation

Reactivity Controlling Factors for an Aromatic Carbon‐Centered σ,σ,σ‐Triradical: The 4,5,8‐Tridehydroisoquinolinium Ion

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