Generation and NMR studies of stable cations derived from monothia[3.2]- and dithia[3.3]metacyclophanes

Laali, Kenneth K.; Okazaki, Takao; Mitchell, Reginald H.

doi:10.1039/b100265l

Cited by 5 publications

(2 citation statements)

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“…We have described an original synthetic pathway for the preparation of new members of the class of thiaCP S-oxides. 2a,c,d The proposed strategy allowed the obtainment of these cages in mild reaction conditions. The key step of the synthetic process is the thermal syn -addition sulfenic acid/carbon−carbon triple bond.…”

Section: Discussionmentioning

confidence: 99%

Thiacyclophane Cages and Related Bi- and Tripodal Molecules via Transient Polysulfenic Acids

et al. 2007

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A series of bis- and tris-bridged thiacyclophane S-oxides, as racemates or meso products, have been synthesized with a new procedure. Starting from the corresponding thiols, in three steps, transient polyarene- and polyarylmethane-sulfenic acids were generated in the presence of di- and triethynylbenzenes. The thermal syn-addition of these sulfenic acids onto the triple bonds of the unsaturated acceptors was conducted in CH2Cl2 at 40 degrees C. The concentration of sulfoxide precursors of sulfenic acid and the sulfoxide/acceptor molar ratio addressed the syn-addition toward open-chain benzene sulfoxides or thiacyclophane S-oxides. Complete stereochemical control was observed in some reactions between polysulfenic acids and ethynylbenzenes, where the meso dithiacyclophane S,S'-dioxides were obtained exclusively, whereas 1:1 mixtures of meso/rac dithiacyclophanes S,S'-dioxides were isolated as products of other reactions. In almost all the cases, the obtained compounds were separated by column chromatography. The structure assignment of the new heterophanes was done on the basis of their diagnostic NMR spectra and X-ray crystallographic analysis of some of them. Open-chain polysulfinyl and polysulfinylmethyl benzenes, obtained as meso/rac mixtures, were separated and the products were fully characterized. Both synthesized cages, including trithia[3(3)](1,3,5)cyclophane S,S',S' '-trioxides, and bi- and tripodal benzene sulfoxides, appear promising in the field of coordination and material chemistry.

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Section: Discussionmentioning

confidence: 99%

Thiacyclophane Cages and Related Bi- and Tripodal Molecules via Transient Polysulfenic Acids

et al. 2007

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“…In continuation of our studies on cyclophane cations [4][5][6][7][8] and annulenium ions [9][10][11][12][13] we report here on stable-ion NMR spectroscopy and computational studies of novel mono-and dications from tri-, tetra-, and pentabridged cyclophanes …”

Section: Full Papermentioning

confidence: 99%

Stable‐Ion NMR Spectroscopy and GIAO‐DFT Study of Carbocations Derived from Multibridged [3_n]Cyclophanes

et al. 2009

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Mono-and diprotonation of the tri-, tetra-, and pentabridged cyclophanes [3 3 ](1,3,5)cyclophane (4), [3 4 ](1,2,3,5)cyclophane (5), and [3 5 ](1,2,3,4,5)cyclophane (6) were realized, and NMR spectroscopic studies of the resulting carbocations are reported. Unlike [2.2]paracyclophane and its fluorinated analogs that are protonated at a position ipso to the ethanobridge, the monocations derived from 4, 5, and 6 are protonated at the unsubstituted ring positions. Protonation regioselectivity in the dications is pseudo-meta for 4 and 5 at unsubstituted ring positions, but for more-crowded 6 the second protonation occurs at a position that is ipso to the trimethyl- IntroductionSynthesis, structural/conformational features, and chemical transformations of cyclophanes, in particular their electrophilic substitution chemistry and directive effects, have fascinated organic chemists for decades. Recent progress in cyclophane chemistry has been summarized in several authoritative chapters and books. [1] It is almost four decades since Hefelfinger and Cram [2] reported the direct NMR spectroscopic observation of ipso monoprotonated [2.2]paracyclophane 1H + in FSO 3 H/ SO 2 ClF (Figure 1). A decade later, Hopf and associates [3] succeeded in the generation of the doubly ipso protonated 1H 2 2+ in "magic acid"/SO 2 ClF at -110°C. Double ipso protonation in 1H 2 2+ increases angle deformation, which in turn decreases charge-charge repulsion.Two ene bridge. Transannular π-π interactions in the monocations are manifested in the observed proton deshielding in the unprotonated π-deck. DFT and GIAO-DFT were employed to study the mono-and dications for comparison with the solution studies in superacids. GIAO-derived ∆NICS (1) Protonation of 2 leads to shielding of the arenium ion protons by the fluorinated deck, showing that the direction of transannular π-electron drain can be reversed upon the 2 Ǟ 2H + transformation.K. K. Laali, T. Okazaki, T. Kitagawa, T. Shinmyozu FULL PAPERIn continuation of our studies on cyclophane cations [4][5][6][7][8] and annulenium ions [9][10][11][12][13] we report here on stable-ion NMR spectroscopy and computational studies of novel mono-and dications from tri-, tetra-, and pentabridged cyclophanes

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“Durch den Raum” konjugierte Cyclophanpolymere

Morisaki

Chujo

2006

Angewandte Chemie

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Konjugierte Polymere haben einzigartige optische und elektronische Eigenschaften, die zu vielfältigen Anwendungen als optoelektronische Materialien und molekulare Funktionseinheiten geführt haben. Während aber in der Chemie sowohl der Cyclophane als auch der konjugierten Polymere bemerkenswerte Fortschritte zu verzeichnen sind, wurden bislang nur wenige Beispiele für Synthesen von konjugierten Polymeren mit Cyclophaneinheiten in der Hauptkette beschrieben. Dieser Kurzaufsatz fasst aktuelle Entwicklungen bezüglich Synthesen, Eigenschaften und Anwendungen von “durch den Raum” konjugierten Polymeren auf Cyclophanbasis zusammen.

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Generation and NMR studies of stable cations derived from monothia[3.2]- and dithia[3.3]metacyclophanes

Cited by 5 publications

References 14 publications

Thiacyclophane Cages and Related Bi- and Tripodal Molecules via Transient Polysulfenic Acids

Thiacyclophane Cages and Related Bi- and Tripodal Molecules via Transient Polysulfenic Acids

Stable‐Ion NMR Spectroscopy and GIAO‐DFT Study of Carbocations Derived from Multibridged [3_n]Cyclophanes

“Durch den Raum” konjugierte Cyclophanpolymere

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Generation and NMR studies of stable cations derived from monothia[3.2]- and dithia[3.3]metacyclophanes

Cited by 5 publications

References 14 publications

Thiacyclophane Cages and Related Bi- and Tripodal Molecules via Transient Polysulfenic Acids

Thiacyclophane Cages and Related Bi- and Tripodal Molecules via Transient Polysulfenic Acids

Stable‐Ion NMR Spectroscopy and GIAO‐DFT Study of Carbocations Derived from Multibridged [3n]Cyclophanes

“Durch den Raum” konjugierte Cyclophanpolymere

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Stable‐Ion NMR Spectroscopy and GIAO‐DFT Study of Carbocations Derived from Multibridged [3_n]Cyclophanes