Nitration of bridged hydronaphthalenes. Fused -effect

Tanida, Hiroshi; Muneyuki, Ryonosuke

doi:10.1016/s0040-4039(00)71731-x

Cited by 11 publications

(11 citation statements)

References 5 publications

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“…The positions of the introduced nitro groups were clearly assigned by 2D NMR experiments (see Figures S13–S15 in the Supporting Information). This substitution pattern is in line with the fused ortho ‐effect that is often observed in triptycene chemistry . Amide cage 4 can also be brominated with NBS in DMF at the same position as where the nitration took place.…”

Section: Figuresupporting

confidence: 80%

Transformation of a [4+6] Salicylbisimine Cage to Chemically Robust Amide Cages

et al. 2019

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In recent years, interest in shape‐persistent organic cage compounds has steadily increased, not least because dynamic covalent bond formation enables such structures to be made in high to excellent yields. One often used type of dynamic bond formation is the generation of an imine bond from an aldehyde and an amine. Although the reversibility of the imine bond formation is advantageous for high yields, it is disadvantageous for the chemical stability of the compounds. Amide bonds are, in contrast to imine bonds much more robust. Shape‐persistent amide cages have so far been made by irreversible amide bond formations in multiple steps, very often accompanied by low yields. Here, we present an approach to shape‐persistent amide cages by exploiting a high‐yielding reversible cage formation in the first step, and a Pinnick oxidation as a key step to access the amide cages in just three steps. These chemically robust amide cages can be further transformed by bromination or nitration to allow post‐functionalization in high yields. The impact of the substituents on the gas sorption behavior was also investigated.

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Section: Figuresupporting

confidence: 80%

Transformation of a [4+6] Salicylbisimine Cage to Chemically Robust Amide Cages

et al. 2019

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“…The values derived from the spectra in Table II follow: ortho, 60.5; meta, 75.1; and para, 71.5. Differences in thermochemical stability are evidenced by the heats of com-bustion7-ortho, -703.2; meta, -694.7; para, -692.0 kcal/mol-and by relative decomposition rates as neat (6) For parallel effects in the mass spectra of stereoisomers, see S. Meyerson and A, W. Weitkamp, Org. Mass Spectrom., 1, 659 (1968); 2, 603 (1969).…”

Section: Results áNd Discussionmentioning

confidence: 99%

“…The reaction steps postulated here all have known close analogs in the pyrolysis of nitrobenzene.lb The symbol Ph is used to denote a benzene ring or Conditions: 0.01 mol of dinitrobenzene, 0.1 mol of benzene-d6; isotopic composition of benzene, 3.6% d5; 96.4% d6; contact time, for m-dinitrobenzene, 8.5 sec, and, for o-and p-dinitrobenzenes, 5 sec; Ns at 10 cc/min. 6 Estimated from low-volt age (7.5 ionizing V nominal) mass spectrum. c Relative intensity of molecular ions summed for each chemical species in the low-voltage spectrum, normalized to total 100%.…”

Section: Results áNd Discussionmentioning

confidence: 99%

Mass spectral and thermal reactions of dinitrobenzenes

Fields¹,

Meyerson²

1972

J. Org. Chem.

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Thermal reactions of dinitrobenzenes can be explained in terms of initial decomposition to NO, and nitrophenyl radicals, paralleling primary loss of NO, in the mass spectrum. To some extent the nitrophenyl radicals in turn lose NO, and give products formally derived from phenylene diradicals. o-Dinitrobenzene gives naphthalene derivatives with benzene-d6 and hexafluorobenzene, suggesting some concerted loss of NO, groups to yield benzyne. Formation of benzofurazan both in the mass spectrum and among thermal reaction products of o-dinitrobenzene points to interaction between the nitro groups in this isomer.Nitrobenzene at 600°d ecomposes to phenyl radical and NO2.1 Similar fragmentation of dinitrobenzenes C6H5NO, -C6H5• + NO,• should give products formally derived from phenylene diradicals. In particular, concerted decomposition of o-dinitrobenzene should yield benzyne, perhaps as a diradical, a species for which little evidence thus far has been found in either liquid or gas phase.

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“…For example, nitration of the parent triptycene (HNO 3 /AcOH in Ac 2 O, 27–29 °C) yields products with the α to β substitution ratio of 1 to 40 [ 100 ]. This feature is a manifestation of the so-called “fused ortho effect” [ 101 ], according to which the reactivity toward electrophiles is largely diminished at the positions of the aryl ring that are ortho in respect to a fused strained ring [ 102 ]. In other words, a strained ring, such as triptycene’s bicyclo [2.2.2]octatriene, acts as a deactivating, meta / para directing group when fused with an arene.…”

Section: Progress In Triptycene Synthesis and Derivatizationmentioning

confidence: 99%

Triptycene Derivatives: From Their Synthesis to Their Unique Properties

2021

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Since the first preparation of triptycene, great progress has been made with respect to its synthesis and the understanding of its properties. Interest in triptycene-based systems is intense; in recent years, advances in the synthetic methodology and properties of new triptycenes have been reported by researchers from various fields of science. Here, an account of these new developments is given and placed in reference to earlier pivotal works that underpin the field. First, we discuss new approaches to the synthesis of new triptycenes. Progress in the regioselective synthesis of sterically demanding systems is discussed. The application of triptycenes in catalysis is also presented. Next, progress in the understanding of the relations between triptycene structures and their properties is discussed. The unique properties of triptycenes in the liquid and solid states are elaborated. Unique interactions, which involve triptycene molecular scaffolds, are presented. Molecular interactions within a triptycene unit, as well as between triptycenes or triptycenes and other molecules, are also evaluated. In particular, the summary of the synthesis and useful features will be helpful to researchers who are using triptycenes as building blocks in the chemical and materials sciences.

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Nitration of bridged hydronaphthalenes. Fused -effect

Cited by 11 publications

References 5 publications

Transformation of a [4+6] Salicylbisimine Cage to Chemically Robust Amide Cages

Transformation of a [4+6] Salicylbisimine Cage to Chemically Robust Amide Cages

Mass spectral and thermal reactions of dinitrobenzenes

Triptycene Derivatives: From Their Synthesis to Their Unique Properties

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