Untersuchungen in der Cyclobutanreihe, XI. Über die stereoisomeren Cyclooctatetraen‐dichloride und das <i>cis</i>‐3.4‐Dichlor‐cyclobuten

Avram, Margarete; Dinulescu, I. G.; Elian, M.; Farcasiu, M.; Marica, Elise; Mateescu, Georg; Nenitzescu, Costin D.

doi:10.1002/cber.19640970209

Cited by 38 publications

(14 citation statements)

References 15 publications

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“…Although the parent cycloheptenyl cation 3a was successfully generated from the allylic alcohol 4 (R = H) in FSOgH-SbFs diluted with S02C1F at -78°, in SbF6-S02CIF solution, a considerable amount of uncharacterized materials were formed. We also treated 1 -acetoxy-2-cycloheptene (6), l-bromo-2-cycloheptene (7), 1,3-cycloheptadiene (8), and cycloheptene (9) with either FS03H-SbF5 or SbF5 in SO.C1F at' -78°( or lower temperatures). Only compounds 6 and 7 give ion 3c (~30% in the latter case, and polymeric materials).…”

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“…TsObicyclo 6,12 In the light of these results, we have attempted to ionize 9,9r/ 'Ts acetolysis ^^x0Ac dihalobicyclo[6.l.Ojnonane (22, X = Cl or Br) in both X X 23 FS03H-SbF5-S02ClF and SbF5-S02ClF solutions at -78°. When 9,l.Ojnonane (22, X = Br) was carefully added to the superacid solutions at -78°, a dark solution was formed immediately and the nmr spectrum showed only uncharacterized materials.…”

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confidence: 99%

“…In case of cyclopentenyl cations, a decrease of 10.2 Journal of the American Chemical Society / 94:18 / September 6,1972 " Carbon-13 shifts are in parts per million from CS2 (external). For simplicity, only the carbon shifts of the allylic part are shown.…”

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“…For simplicity, only the carbon shifts of the allylic part are shown. 6 Only the carbon shift(s) of the methyl carbon indicated by an asterisk is shown. ppm is observed for the central allylic carbon chemical shift, where increases of 6-8 and 10 ppm are observed in case of cyclohexenyl and cycloheptenyl cations, respectively.…”

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Stable carbocations. CXXXVII. Cycloheptenyl, cyclooctenyl, and cyclononenyl cations

Oláh¹,

Liang²

1972

J. Am. Chem. Soc.

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and 13C nuclear magnetic resonance spectral studies of cycloheptenyl, cyclooctenyl, and cyclononenyl cations and some of their derivatives are reported and compared with those of cyclopentenyl and cyclohexenyl cations. All the cycloallylic cations were studied in two different superacid solvents, FS03H-SbF5 and SbFj diluted with S02C1F (S02) at low temperature. The parent cycloheptenyl cation was observed, while the parent cyclooctenyl and cyclononenyl cations were found to be unstable even in superacid media, although a series of substituted derivatives were obtained. The stabilities of cycloalkenyl cations decrease as the ring size increases. The equilibration of the stereoisomers of protonated 2-cyclohepten-l-one and the protonated 2-cycloocten-l-one in FS03H-SbF5-S02ClF solution are also discussed. Variousgroups have investigated the generation of cycloallylic carbocations either in concentrated sulfuric acid or in much stronger superacid solvents.2The characteristic proton magnetic resonance band positions for cycloalkenyl cations have been very well demonstrated by Deno and others.3 Cyclization of linear allylic cations into either cyclopentenyl or cyclohexenyl cations and the equilibrium between the latter two allylic cations have also been paid much attention.4 However, among the reported cycloalkenyl cations only substituted cyclobutenyl,5-6 cyclopentenyl, and cyclohexenyl cations have been directly observed: no unsubstituted derivatives and larger cycloalkenyl cations such as cycloheptenyl,7 cyclooctenyl, and cyclononenyl cations have been observed.

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Stable carbocations. CXXXVII. Cycloheptenyl, cyclooctenyl, and cyclononenyl cations

Oláh¹,

Liang²

1972

J. Am. Chem. Soc.

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“…Our target anti- [3]-ladderdiene 10 had previously been prepared by Nenitzescu and coworkers by the dimerization of dichlorocyclobutene (23). However, that synthesis yielded an inseparable mixture of ladderene diastereomers and hydrocarbon byproducts, used chlorine gas, and required a 200-fold excess of lithium-mercury amalgam (Fig.…”

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Mechanochemical Synthesis of Elusive Fluorinated Polyacetylene

Boswell¹,

Mansson²,

Cox³

et al. 2019

Preprint

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<p>Polymer mechanochemistry has traditionally been employed to study the effects of mechanical force on one or two chemical bonds within a polymer. It is underexploited for the scalable synthesis of wholly new materials by activating bonds along the entire polymer, especially products inaccessible by other means. Herein we utilize polymer mechanochemistry to synthesize fluorinated polyacetylene, a long-sought-after air-stable polyacetylene that has eluded synthesis by conventional means. Our synthetic approach proceeds via ultrasonication of a force-responsive precursor polymer that was synthesized in five steps on gram scale. The synthesis is highlighted by rapid incorporation of fluorine in an exotic photochemical cascade whose mechanism and exquisite diastereoselectivity were elucidated by computation. </p>

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cis ‐3,4‐Dichlorocyclobutene

Pettit

Henery

2003

Organic Syntheses

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Untersuchungen in der Cyclobutanreihe, XI. Über die stereoisomeren Cyclooctatetraen‐dichloride und das cis‐3.4‐Dichlor‐cyclobuten

Abstract: Wir fanden, d a B bei der Diensynthese des rohen Dichlorids mit Acetylendicarbonsaure-dimethylester n e b n dem tekant1ten2~4) Addukt mit Schmp. 127" in wechselnden "'m C1 -I_\

Cited by 38 publications

References 15 publications

Stable carbocations. CXXXVII. Cycloheptenyl, cyclooctenyl, and cyclononenyl cations

Stable carbocations. CXXXVII. Cycloheptenyl, cyclooctenyl, and cyclononenyl cations

Mechanochemical Synthesis of Elusive Fluorinated Polyacetylene

cis ‐3,4‐Dichlorocyclobutene

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