Rearrangement of fused tetracyclic heterocycles induced by alkyl halides and formation of a new type of ‘proton sponge’

Zachová, Hana; Man, Stanislav; Taraba, Jan; Potáček, Milan

doi:10.1016/j.tet.2008.11.057

Cited by 20 publications

(28 citation statements)

References 14 publications

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“…Derivatives of tetrathiafulvalenes with triiodide anion have attracted attention since the eighties, as the organic radical cation salts, or organic superconductors . Salts with protonated tertiary amines and metal triiodide complexes are often reported in the literature ,. Also a quite rare example of protonated arsine oxide has been found .…”

Section: Introductionmentioning

confidence: 99%

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

et al. 2018

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The intriguing properties of triiodide organic salts ([(C6H5)3AsO]2H+I3−, (C6H5CH2)3NH+I3− ⋅C6H5CH3, and [(C6H5CH2)3NO]2H+I3−) have been analyzed in detail using experimental and theoretical techniques. The analysis of crystal structures, density of states distribution and photocurrent generation of this purely ionic materials indicates insulating character of the ground state, whereas semiconducting character in higher excited states is observed. These peculiar properties of the studied compounds are the consequence of a specific electronic structure: very flat dispersion diagrams of the valence and conduction band and highly dispersive character on the higher conduction band. Weak triiodide‐triiodide interactions play the key role in the visible absorption range of these salts, while the charge transfer involving high energy carbon‐centered states is responsible for photocurrent generation. The complexity of the electrochemical reactions and the interactions of the I3− anion with light, solubility in organic solvents and the simplicity of preparation make these materials interesting candidates for application in unconventional optoelectronic devices.

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Section: Introductionmentioning

confidence: 99%

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

et al. 2018

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“…Potáček et al. reported on the preparation of caged proton sponges with a non‐aromatic skeleton 27. Recently, the basicity of macrocyclic amino compounds with interacting basicity centers was studied theoretically and experimentally 28.…”

Section: Introductionmentioning

confidence: 99%

Superbasic Alkyl‐Substituted Bisphosphazene Proton Sponges: Synthesis, Structural Features, Thermodynamic and Kinetic Basicity, Nucleophilicity and Coordination Chemistry

Kögel

Xie

Baal

et al. 2014

Chemistry A European J

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Herein we describe an easily accessible class of superbasic proton sponges based on the 1,8-bisphosphazenylnaphthalene (PN) proton pincer motif and P-alkyl substituents ranging from methyl (TMPN) to n-butyl (TBPN), isopropyl (TiPrPN) and cyclopentyl (TcyPPN). These neutral bases with a pK(BH)(+) value (MeCN) of ~30 were accessible via a Kirsanov condensation using commercially available 1,8-diaminonaphthalene, and in case of TMPN and TBPN, simple one-pot procedures starting from trisalkylphosphanes can be performed. Furthermore, the known pyrrolidinyl-substituted superbase TPPN previously synthesized via a Staudinger reaction could also be prepared by the Kirsanov strategy allowing its preparation in a larger scale. The four alkyl-substituted proton sponges were structurally characterized in their protonated form; molecular XRD structures were also obtained for unprotonated TiPrPN and TcyPPN. Moreover, we present a detailed description of spectroscopic features of chelating bisphosphazenes including TPPN and its hyperbasic homologue P2-TPPN on which we reported recently. The four alkyl-substituted superbases were investigated with respect to their basic features by computational means and by NMR titration experiments revealing unexpectedly high experimental pK(BH)(+) values in acetonitrile between 29.3 for TMPN and 30.9 for TBPN. Besides their thermodynamic basicity, we exemplarily studied the kinetic basicity of TMPN and TPPN by means of NMR-spectroscopic methods. Furthermore, the competing nucleophilic versus basic properties were examined by reacting the proton sponges with ethyl iodide. Insight into the coordination chemistry of chelating superbases was provided by reacting TMPN with trimethylaluminum and trimethylgallium to give cationic complexes of Group XIII metal alkyls that were structurally characterized.

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“…Main recent papers describing synthesis of perhydrotriazolotriazoles by classical method, 19,20 but this method has defects such as long reaction times and low yield. Herein we report a facial and efficient method for the synthesis perhydrotriazolotriazoles catalyzed by TiCl 4 .…”

Section: Resultsmentioning

confidence: 99%

New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl₄under Ambient Conditions

Safari

Gandomi‐Ravandi²,

Ghotbinejad³

2012

Journal of the Korean Chemical Society

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Rearrangement of fused tetracyclic heterocycles induced by alkyl halides and formation of a new type of ‘proton sponge’

Cited by 20 publications

References 14 publications

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

Superbasic Alkyl‐Substituted Bisphosphazene Proton Sponges: Synthesis, Structural Features, Thermodynamic and Kinetic Basicity, Nucleophilicity and Coordination Chemistry

New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl₄under Ambient Conditions

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Rearrangement of fused tetracyclic heterocycles induced by alkyl halides and formation of a new type of ‘proton sponge’

Cited by 20 publications

References 14 publications

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

Triiodide Organic Salts: Photoelectrochemistry at the Border between Insulators and Semiconductors

Superbasic Alkyl‐Substituted Bisphosphazene Proton Sponges: Synthesis, Structural Features, Thermodynamic and Kinetic Basicity, Nucleophilicity and Coordination Chemistry

New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl4under Ambient Conditions

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New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl₄under Ambient Conditions