Untersuchungen zur Lewis-Acidität fluorierter Sulfonium-Ionen

On the Lewis Acidity of Fluorinated Sulfonium Ions NMR investigations show, that sulfonium salts [(CF₃)_nSF_3?n]⁺ AsF₆^? ( 1–3 , n = 0–2) add CH₃CN under formation of ψ-pentacoordinated sulfuranonium ions [(CF₃)_nSF_3?n · NCCH₃]⁺ ( 1a – 3a ,) with the donor in an axial position. In solution NSF₃ ( 4 ,) forms similar salts [(CF₃)_nSF_3?n · NSF₃]⁺ AsF₆^? ( 1b-3b ,) with weaker donor-acceptor interactions. With NSF₂NMe₂ ( 5 ,) the step of the primary addition products is passed very quickly, by fluoride-migration from 1 , and 2 , persulfuranonium ions [(CH₃)₂NSF₃NSF₂]⁺ ( 6 ,) and [(CH₃)₂NSF₃NSFCF₃]⁺ ( 7 ,), respectively, are formed, while from 3 , only decomposition products (Me₂NSF₂⁺, CF₃SSCF₃, CF₄) were obtained.     

Oxidation and nitrosation of 4-(3-alkylureido)-2, 2, 6, 6-tetramethylpiperidine-1-oxyls to 4-(3-alkyl-3-nitrosoureido)-2, 2, 6, 6-tetramethyl-1-oxopiperidinium salts

4-(3-Alkylureido)-2, 2, 6, 6-tetramethylpiperidine-1-oxyls are rapidly oxidized by N₂O₄ or NOCl to 4-(3-alkylureido)-2, 2, 6, 6-tetramethyl-1-oxopiperidinium nitrates and chlorides, which are then nitrosated to 4-(3-alkyl-3-nitrosoureido)-2, 2, 6, 6-tetramethyl-1-oxopiperidinium salts. The perchlorates of the latter were prepared by an exchange reaction with HClO₄. The nitrosation of alkylureidooxoammonium salts is the first example of chemical modification of oxoammonium derivatives in which the highly reactive >N⁺=O group is inert toward the reagent.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 542–547, March, 1993.     

Halobismuth(III) salts with substituted aminopyridinium cations

The crystal structures of six halobismuth(III) salts of variously substituted aminopyridinium cations display discrete mononuclear [BiCl₆]^3? and dinuclear [Bi₂X₁₀]^4? anions (X = Cl or Br), and polymeric cis‐double‐halo‐bridged [Bi_nX_4n]^n? anionic chains (X = Br or I). Bis(2‐amino‐3‐ammoniopyridinium) hexachloridobismuth(III) chloride monohydrate, (C₅H₉N₃)₂[BiCl₆]Cl·H₂O, (1), contains discrete mononuclear [BiCl₆]^3? and chloride anions. Tetrakis(2‐amino‐3‐methylpyridinium) di‐μ‐chlorido‐bis[tetrachloridobismuth(III)], (C₆H₉N₂)₄[Bi₂Cl₁₀], (2), tetrakis(2‐amino‐3‐methylpyridinium) di‐μ‐bromido‐bis[tetrabromidobismuth(III)], (C₆H₉N₂)₄[Bi₂Br₁₀], (3), and bis(4‐amino‐3‐ammoniopyridinium) di‐μ‐chlorido‐bis[tetrachloridobismuth(III)] dihydrate, (C₅H₉N₃)₂[Bi₂Cl₁₀]·2H₂O, (4), incorporate discrete [Bi₂X₁₀]^4? anions (X = Cl or Br), while catena‐poly[2,6‐diaminopyridinium [[cis‐diiodidobismuth(III)]‐di‐μ‐iodido]], {(C₅H₈N₃)[BiI₄]}_n, (5), and catena‐poly[2,6‐diaminopyridinium [[cis‐dibromidobismuth(III)]‐di‐μ‐bromido]], {(C₅H₇N₂)[BiBr₄]}_n, (6), include [Bi_nX_4n]^n? anionic chains (X = Br or I). Structures (2) and (3) are isostructural, while that of (5) is a pseudomerohedral twin. There is no discernible correlation between the type of anionic species obtained and the cation or halide ligand used. The Bi^III centres always have a slightly distorted octahedral geometry and there is a correlation between the Bi—X bond lengths and the number of classic N—H…X hydrogen bonds that the X ligand accepts, with a greater number of interactions corresponding with slightly longer Bi—X distances. The supramolecular networks formed by classic N—H…X hydrogen bonds include ladders, bilayers and three‐dimensional frameworks.     

CH‐Directed Anion–π Interactions in the Crystals of Pentafluorobenzyl‐Substituted Ammonium and Pyridinium Salts

Simple pentafluorobenzyl‐substituted ammonium and pyridinium salts with different anions can be easily obtained by treatment of the parent amine or pyridine with the respective pentafluorobenzyl halide. Hexafluorophosphate is introduced as the anion by salt metathesis. In the case of the ammonium salt 4 , water co‐crystallisation seems to suppress effective anion–π interactions of bromide with the electron‐deficient aromatic system, whereas with salts 5 and 6 such interactions are observed despite the presence of water. However, due to asymmetric hydrogen‐bonding interactions with ammonium side chains, the anion of 5 is located close to the rim of the pentafluorophenyl group (η¹ interaction). In 6 the CH–anion hydrogen bonding is more symmetric and fixes the anion on top of the ring (η⁶). A similar structure‐controlling effect is observed in case of the 1,4‐diazabicyclo[2.2.2]octane derivatives 7 . Here the position of the anion (Cl, Br, I) is shifted according to the length of the weak CH–halide interaction. The hexafluorophosphate 7 d reveals that this “non‐coordinating” anion can be located on top of an aromatic π system. In the methyl‐substituted pyridinium salts 9 and 10 different locations of the bromide anions with respect to the π system are observed. This is due to different conformations of the mono‐ versus disubstituted pyridine, which leads to different directions of the weak, but structurally important, H_Me? Br bonds.     

Tosyiate of ethyl 3-amino-2-phenyliodoniocrotonate: Synthesis, crystal structure, and synthesis of heterocyclic compounds based on it

Ethyl 3-aminocrotonate, when reacted with hydroxy(tosyloxy)iodobenzene, forms the tosylate of ethyl 3-amino-2-phenyliodoniocrotonate which crystallizes well in up to 80% yield. X-ray analysis confirms the structure of the phenyliodonium salt, revealing intramolecular and unusual intermolecular hydrogen bonds, stabilizing the compound in the crystalline state. Reaction with pyridine, its 4-substituted derivatives, and 4,4-bipyridine yields tosylates of 2-pyridinio-substituted ethyl 3-aminocrotonates.¹H NMR and IR spectra support formation of an intramolecular hydrogen bond for the E-isomer, and iodonium salts in the case of pyridinium salts for the Z-isomer. The UV spectra of the pyridinium salts show an intramolecular charge transfer band.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 770–777, June, 2000.     

The Structural Systematics of Protonation of Some Important Nitrogen‐base Ligands. I Some Univalent Anion Salts of Doubly Protonated 2, 2′:6′, 2″‐Terpyridyl

A number of salts of 2,2′:6′,2″ ‐terpyridyl (‘tpy’) with univalent anions (halides : X = Cl, Br, I; oxyanions of increasing basicity: ClO₄, NO₃, ‘tfa’ = trifluoroacetate, ‘tca’ = trichloroacetate), variously solvated, have been structurally characterized by single crystal X‐ray studies. In all cases the tpy moieties are found to be doubly protonated [tpyH₂]²⁺, the hydrogen atoms being associated with the nitrogen atoms of the peripheral rings, these together with the central nitrogen atom being directed towards a common focus, in most cases ‘chelating’ one of the counter‐ion components in diverse ways. Thus the chloride and bromide compounds are isomorphous [(tpyH₂)X]⁺X⁻·H₂O arrays; a second dihydrate phase is also described for the chloride, the two forms having the unchelated anion and water molecules engaged in hydrogen‐bonded networks essentially independent of [(tpyH₂)X]⁺. The iodide is anhydrous, and of a different structural type, the anions, presumably too large for chelation, lying out of plane to either side, and linking different cations into a one‐dimensional polymer; in the perchlorate, the unsolvated aggregate is now discrete [(tpyH₂)X₂], a pair of perchlorate ions disposed to either side of the tpy plane, lying each with one oxygen atom interacting with both of the two protonating hydrogen atoms. In the anhydrous X = NO₃, tfa, tca arrays, the lattices are solvated by the parent acids; one oxygen atom of each anion is chelated by the [tpyH₂]²⁺ as in the chlorides, the other anion, with the acid, forming an independent ‘acid salt’ counterion [XHX]⁻ in each case, retaining the additional protonic hydrogen rather than further protonating the central ring, all being of the form [(tpyH₂)X]X·HX = [(tpyH₂)X][X(HX)].     

Zur Reaktion von Bis(hydroxyphenyl)methanen mit Phosphorpentachlorid — Phosphocine mit Phosphonium‐ und Phosphoranstruktur [1]

The Reaction of Bis(hydroxyphenyl)methanes with Phosphorus Pentachloride — Phosphocins with Phosphonium and Phosphorane Structure [1] Bis(2‐hydroxyphenyl)methane derivatives react with phosphorus pentachloride to give cyclic dioxaphosphocinium salts, as well as trichloro‐dioxaphosphocins. Chlorination of 6‐chloro‐dioxaphosphocins also leads to trichloro‐dioxaphosphocins. Hydrolysis of the dioxaphosphocin derivatives gives stable cyclic phosphates.     

Bis(perfluoroorganyl)bromonium salts [(RF)2Br]Y (RF = aryl, alkenyl, and alkynyl)

Bromonium salts [(R_F)₂Br]Y with perfluorinated groups R_FC₆F₅, CF₃CFCF, C₂F₅CFCF, and CF₃C≡C were isolated from reactions of BrF₃ with R_FBF₂ in weakly coordinating solvents (wcs) like CF₃CH₂CHF₂ (PFP) or CF₃CH₂CF₂CH₃ (PFB) in 30-90% yields. C₆F₅BF₂ formed independent of the stoichiometry only [(C₆F₅)₂Br][BF₄]. 1:2 reactions of BrF₃ and silanes C₆F₅SiY₃ (Y = F, Me) ended with different products - C₆F₅BrF₂ or [(C₆F₅)₂Br][SiF₅] - as pure individuals, depending on Y and on the reaction temperature (Y = F). With C₆F₅SiF₃ at ≥−30 °C [(C₆F₅)₂Br][SiF₅] resulted in 92% yield whereas the reaction with less Lewis acidic C₆F₅SiMe₃ only led to C₆F₅BrF₂ (58%). The interaction of K[C₆F₅BF₃] with BrF₃ or [BrF₂][SbF₆] in anhydrous HF gave [(C₆F₅)₂Br][SbF₆]. Attempts to obtain a bis(perfluoroalkyl)bromonium salt by reactions of C₆F₁₃BF₂ with BrF₃ or of K[C₆F₁₃BF₃] with [BrF₂][SbF₆] failed. The 3:2 reactions of BrF₃ with (C₆F₅)₃B in CH₂Cl₂ gave [(C₆F₅)₂Br][(C₆F₅)_nBF_4−n] salts (n = 0-3). The mixture of anions could be converted to pure [BF₄]⁻ salts by treatment with BF₃·base.     

有机胂化合物的研究(ⅩⅧ)——溶剂对溴化(邻氟苄基)三苯钟与芳醛反应产物生成的影响

近年来,黄耀曾等应用有机鉮盐原地生成叶立德并将它用于有机合成,使叶立德化学有了更大的发展,我们将原地生成的胂叶立德与羰基化合物反应,产物为环氧化合物或烯烃,影响反应产物的因素除胂叶立德的结构外,溶剂效应往往起决定作用,为了进一步研究半稳定胂叶立德的反应性能,寻求有利的反应条件,探索溶剂效应。     

ESR Studies on N-Alkylphenothiazine Radical Cation Salts

ＥＳＲＳｔｕｄｉｅｓｏｎＮ－ＡｌｋｙｌｐｈｅｎｏｔｈｉａｚｉｎｅＲａｄｉｃａｌＣａｔｉｏｎＳａｌｔｓＧＵＯＱｉｎｇ－ｘｉａｎｇ￣（１,２）,ＬＩＵＢｏ￣１ａｎｄＬＩＵＹｏｕ－ｃｈｅｎｇｉ￣（１,２）．（￣＊ＮａｔｉｏｉｉａｌＬａｂｏｒａｔｏｒｙｏｆＡ...     

Electrochemical synthesis of coatings in the system Ti-Si-B from molten salts

Powder and coatings of metal-like refractory compounds (MLRC) can be produced by electrochemical synthesis from molten salts. The stoichiometry of the deposited MLRC was found to correlate with the molar ratio of MLRC component ions in the melts. The system Ti-Si-B is of particular interest in terms of electrochemical synthesis since the titanium, silicon and boron potentials in the melt are close together. The electrochemical synthesis has been investigated in the system NaCl-KCl-NaF-K₂TiF₆-K₂SiF₆-KBF₄ at 700°C. The opportunity of deposition of new ternary compound in the system Ti-Si-B is shown by the electrochemical synthesis from molten salts.     

Novel synthesis of indolizidines and quinolizidines

A very short synthesis of indolizidines, quinolizidines and some higher homologues was developed by alkylation of 2-methyl-1-pyrroline or 6-methyl-2,3,4,5-tetrahydropyridine with 1,3- or 1,4-dihaloalkanes, followed by reduction of the intermediate iminium salts, resulting in the desired 1-azabicyclo[m.n.0]alkanes in good yields.     

The Structural Systematics of Protonation of Some Important Nitrogen‐base Ligands. IV. Some Ethane‐1,2‐diaminium Univalent Anion Salt/1,10‐Phenanthroline (Hydrate) Arrays

Syntheses and single crystal X‐ray structure characterisations are recorded for some novel series of crystalline complexes formed between salts of univalent anions of the ethane‐1,2‐diaminium cation, [enH₂]X₂, and 1,10‐phenanthroline (‘phen’), variously hydrated, thus: [enH₂]X₂·mphen(·nH₂O), for m = 2, 4 and 10 (one example), n various. In all cases, the motifs constituting the arrays comprise columns of [enH₂]²⁺ cations, carrying the protonic array but linked in a second dimension by hydrogen‐bonding to associated anions and water molecules (where present), expanding the column in some cases to form a sheet, different degrees of hydration compensating for changing anion bulk. In a third dimension the protonic hydrogen complement also links to the nitrogenous component of phen stacks which surround the column. Thus, for the m = 2 array, in a triclinic cell, a, b, c broadly 10‐11 (x2), 7Å, α, β, γ 80, 70° (x2), the cation and phen columns lie parallel to c; in the unsolvated trichloroacetate compound, the cation column is associated with anions to either side, these linking into a sheet with water molecules in the more highly hydrated trifluoroacetate (‘tfa’) and nitrate (n = 2), and chloride and bromide (n = 4) arrays (the tfa adduct a superlattice doubled in c). In the m = 4 arrays, an additional phen stack is inserted, forming a sheet with the first in the second dimension for the perchlorate tetrahydrate array, the iodide pentahydrate counterpart being a 2 x c superlattice. A second nitrate salt, m = 10, n = 4, is also described, a complex array of multiple networks of the above type. Single crystal X‐ray structure determinations are also recorded for salts [phenH](PF₆)·phen and [2,9‐Me₂phenH](PF₆). In the phen adduct, the protonic hydrogen atom is closely associated (N···H 0.90(4) Å) with one of the two independent phen moieties, these disposed alternately in a stack up b close to the 2₁ screw axis, so that the hydrogen bridges to the unprotonated moiety (H···N′ 2.36(4) Å) pitched at an angle of 47° to it in the screw‐related stack. In the Me₂phen salt, the phen moieties lie in crystallographic mirror planes, normal to and stacked up b, with the protonic hydrogen atom contacting a PF₆ fluorine atom (H···F 1.96(3) Å). The structure of unsolvated Me₂phen is also recorded.     

The Chemistry of Dichloromethylenammonium Salts (“Phosgenimonium Salts”)

Dichloromethylenammonium salts, particularly dichloromethylenedimethylammonium chloride, occupy a unique place as stable but reactive building blocks for synthesis. They contain three mobile chlorine atoms activated by an amino group on the same carbon atom. These salts can be regarded as chlorinated Vilsmeier or Mannich reagents and are thus at a higher oxidation level. As in the Mannich or Vilsmeier reaction, the carbon condenses here as an electrophile with formation of C? C or C? hetero atom bonds in a variety that is still far from being exhausted.     

Dithiadiazolium salts as initiators for the cationic ring-opening polymerization of tetrahydrofuran

Mono-, bis- and tris-(1,3,2,4-dithiadiazolium) salts [R-(CNSNS ⁺)_n]_n+[AsF^-₆]_n (R = aryl, n = 1, 2, 3) were found to initiate the cationic ring-opening polymerization of tetrahydrofuran (THF) at room temperature to give clear gels from which the pure polymer was precipitated. 1,3,2,4-Dithiadiazolium cations associated with the hard [AsF₆]^- anion thus constitute a new class of cationic polymerization initiators. The poly(THF) formed by initiation with 1,3,2,4-dithiadiazolium cation was characterized by gel permeation chromatography, infrared spectrophotometry, and ¹³C-NMR spectroscopy. Number-average molecular weights of 198 700 g mol^-1 (polydispersity 1.96) and 190 000 g mol^-1 (polydispersity 1.61) were obtained using [PhCNSNS ] [AsF₆] and [C₆H₃-1,3,5-(CNSNS )₃][AsF₆]₃, respectively, as initiators. The use of multifunctional dithiadiazolium salts as initiators suggests that they may be useful in the preparation of starburst and dendritic polymers. © 1992 John Wiley & Sons, Inc.     

Über die Darstellung der Dimercapto(methyl)sulfonium-Salze[CH3S(SH)2]+AsF−6 und [CH3S(SH)2]+SbCl−6 und der Bis(chlorthio)Methylsulfonium-Salze [CH3S(SCI)2]+ AsF6−und [CH3S(SCL)2]+SbCl−6

On the Preparation of Dimercapto(methyl)Sulfonium Salts [CH₃S(SH)₂]⁺ AsF₆^? and [CH₃S(SH)₂]⁺SbCl₆^? and the Bis(chlorothio)methylsulfonium Salts [CH₃S(SCI)₂]⁺ AsF₆^? and [CH₃S(SCI)₂]⁺ SbCl₆^? The preparation of the dimercapto(methyl)sulfonium salts [CH₃S(SH)₂]⁺ AsF₆^? and [CH₃S(SH)₂]⁺SbCl₆^? from [CH₃SCl₂]⁺ salts and H₂S at 195 K is reported. The salts are stable below 210 K. They are characterized by additional Raman spektroscopic measurements of the isotopic labelled cations [CH₃S(SD)₂]⁺, [CH₃S(³⁴SH)₂]⁺ and [CH₃S(₃₄SD)₂]⁺. The dimercapto(methyl)sulfonium salts are transfered into bis(chlorthio)methylsulfonium salts by reaction with Cl₂ at 195 K.     

New versatile organyltellurium(IV) halides: Synthesis and X-ray structural features of the telluronium tellurolate salts [PhTe(CH3)2]2[TeX6] (X = Cl, Br) and [Ph3Te][PhTeX4] (X = Cl, Br, I)

TeX₄ (X = Cl, Br) react in HCl/HBr with [Ph(CH₃)₂Te]X (X = Cl, Br) to give [PhTe(CH₃)₂]₂[TeCl₆] (1) and [PhTe(CH₃)₂]₂[TeBr₆] (2). The reaction of PhTeX₃ (X = Cl, Br, I) in cooled methanol with [(Ph)₃Te]X (X = Cl, Br, I) leads to [Ph₃Te][PhTeCl₄] (3), [Ph₃Te][PhTeBr₄] (4) and [Ph₃Te][PhTeI₄] (5). In the lattices of the telluronium tellurolate salts 1 and 2, octahedral TeCl₆ and TeBr₆ dianions are linked by telluronium cations through Te?Cl and Te?Br secondary bonds, attaining bidimensional (1) and three-dimensional (2) assemblies. The complexes 3, 4 and 5 show two kinds of Te?halogen secondary interactions: the anion-anion interactions, which form centrosymmetric dimers, and two identical sets of three telluronium-tellurolate interactions, which accomplish the centrosymmetric fundamental moiety of the supramolecular arrays of the three compounds, with the tellurium atoms attaining distorted octahedral geometries. Also phenyl C-H?halogen secondary interactions are structure forming forces in the crystalline structures of compounds 3, 4 and 5.     

Synthesis of bridged and metallobridged bis(beta-cyclodextrin)s containing fluorescent oxamidobisbenzoyl linkers and their selective binding towards bile salts

A series of beta-cyclodextrin (beta-CD) dimers containing fluorescent 2,2'-oxamidobisbenzoyl and 4,4'-oxamidobisbenzoyl linkers--that is, 6,6'-[2,2'-oxamidobis(benzoylamino)]ethyleneamino-6,6'-deoxy-bis(beta-CD) (2), 6,6'-[2,2'-oxamidobis(benzoylamino)]diethylenediamino-6,6'-deoxy-bis(beta-CD) (3), 6,6'-[4,4'-oxamidobis(benzoylamino)]ethyleneamino-6,6'-deoxy-bis(beta-CD) (4), and 6,6'-[4,4'-oxamidobis(benzoylamino)]diethylenediamino-6,6'-deoxy- bis(beta-CD) (5)--were synthesized from the corresponding oxamidobis(benzoic acid)s through treatment with mono[6-aminoethyleneamino-6-deoxy]-beta-CD or mono[6-diethylenetriamino-6-deoxy]-beta-CD. Further treatment of 2-5 with copper perchlorate gave their Cu(II) complexes 6-9 in satisfactory yields. The conformation and binding behavior of 2-9 towards two bile salt guests--sodium cholate (CA) and sodium deoxycholate (DCA)--was comprehensively investigated by circular dichroism, 2D NMR spectroscopy, and fluorescence spectroscopy in Tris-HCl buffer solution (pH 7.2) at 25 degrees C. Thanks to the cooperative host-linker-guest binding mode, the stoichiometric 1:1 complexes formed by bis(beta-CD)s 2-5 with bile salts gave high stability constants (KS values) of up to 10(3)-10(4) M(-1). Significantly, benefiting from the intramolecular 1:2 or 2:4 binding stoichiometry, the resulting complexes of metallobis(beta-CD)s 6-9 with bile salts gave much higher KS values of up to 10(6)-10(7) M(-2). The enhanced binding abilities of bis(beta-CD)s and metallobridged bis(beta-CD)s are discussed from the viewpoints of induced-fit interactions and multiple recognition between host and guest.     

Reactions of quinazolinium salts with quaternary heterocyclic salts yielding 3-hetarylquinolines

A novel type of transformations of the pyrimidine ring under the action of C-nucleophiles was found and a new method was developed for the synthesis of 3-hetarylquinolines from quinazoline derivatives and quaternary heterocyclic salts. An independent synthesis was carried out and transformations of one of the probable intermediates were studied. By-products were isolated. The effects of the nature of the heterocycle and substituents on the course of the ring transformation reaction were found, and the mechanism of the reaction was suggested. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1210–1215, June, 1998.