CO2 as a supramolecular assembly agent: a route for lamellar materials with a high content of amine groups

The uptake of carbon dioxide on N-(2-aminoethyl)-3-aminopropyltrimethoxysilane 1 and N-(6-aminohexyl)-3-aminopropyltrimethoxysilane 2 afforded a supramolecular network of bis-silylated ammonium carbamate salts, the hydrolytic polycondensation of which gave rise to structured hybrid materials. Subsequent loss of CO2 was readily achieved upon heating, thus generating materials in which the structure was maintained (well-defined lamellar structure from 2) and contains free amino groups. The accessibility of amine-functionalized groups was shown by their ability to complex transition metal or lanthanide salts.     

The solid-phase Zincke reaction: preparation of omega-hydroxy pyridinium salts in the search for CFTR activation

A study of structural modifications of MPB-07 was undertaken as part of a synthetic program aimed at discovering small molecules with CFTR activation potential. Solid-phase synthesis techniques were used to prepare derivatives of MPB-07 employing the Zincke reaction for the construction of aromatic, quaternary ammonium salts such as those found in 2 or 3. In this transformation, primary amines react with highly electrophilic N-2,4-dinitrophenylpyridinium (DNP) salt 4 to afford pyridinium salt 8 with release of 2,4-dinitroaniline 6. Thus, the reaction of 1-(2,4-dinitrophenyl)pyridinium salts with various polymer-bound amino ethers, followed by cleavage from the resin, delivers the desired salts in good yield and high purity.     

Synthesis of New N-Pivot Lariat Crown Ethers Containing a Propylene Linkage in the Side Arm

A series of new 15- and 18-membered N-pivot lariat aza-crown ethers having a propylene linkage in the side arm was prepared starting from functionalized diethanolamines and functionalized lariat aza-crown ethers containing the easily modified benzotriazole moiety. Addition reactions of such derivatives to electron-rich vinyl ethers or vinylamides followed by displacement of the benzotriazolyl group in the addition products by hydrogen (by reduction with LiAlH(4)) gives a variety of N-(3-oxo-3-substituted)- and N-(3-aza-3-substituted)propylene side-armed derivatives of aza-crown ethers. Stability constants for the complexes of several synthesized lariats with metal cations are discussed.     

Synthesis and reactivity of (C6F5)3B-N-heterocycle complexes. 1. Generation of highly acidic sp3 carbons in pyrroles and indoles

The reaction of pyrroles and indoles with B(C(6)F(5))(3) and BCl(3) produces 1:1 B-N complexes containing highly acidic sp(3) carbons, for example, N-[tris(pentafluorophenyl)borane]-5H-pyrrole (1) and N-[tris(pentafluorophenyl)borane]-3H-indole (2), that are formed by a new formal N-to-C hydrogen shift, the mechanism of which is discussed. With some derivatives, restricted rotation around the B-N bond and/or the B-C bonds was observed by NMR techniques, and some rotational barriers were calculated from experimental data. The acidity of the sp(3) carbons in these complexes is shown by their ability to protonate NEt(3), with formation of pyrrolyl- and indolyl-borate ammonium salts. The driving force for this reaction is given by the restoration of the aromaticity of the heterocycle.     

季铵盐中N-手性在不对称烷基化反应中的作用研究

为了探明手性季铵盐中N-手性在不对称烷基化反应中的作用,从天然氨基酸出发合成了4个仅含C-手性的季铵盐.将它们与4个同时含有C-和N-手性的季铵盐用于催化二苯亚胺甘氨酸叔丁酯的不对称烷基化反应,通过对烷基化产物的ee值进行比较,结果表明简单的链状季铵盐中的N-手性不能对烷基化产物的ee值产生明显影响.     

Polymer-supported Cinchona alkaloid-derived ammonium salts as recoverable phase-transfer catalysts for the asymmetric synthesis of alpha-amino acids

Alkaloids such as cinchonidine, quinine and N-methylephedrine have been N-alkylated using polymeric benzyl halides or co-polymerized and then N-alkylated, thus affording a series of polymer-supported chiral ammonium salts which have been employed as phase-transfer catalysts in the asymmetric benzylation of an N-(diphenylmethylene)glycine ester. These new polymeric catalysts can be easily recovered by simple filtration after the reaction and reused. The best ee's were achieved when Merrifield resin-anchored cinchonidinium ammonium salts were employed.     

Microwave-promoted solvent-free synthesis of N-(diphenylmethylene)glycine alkyl esters

The efficient synthesis of N-(diphenylmethylene) glycine alkyl esters was achieved for the first microwave irradiation under solvent-free condition,using PEG or quaternary ammonium salts as phase transfer catalysts(PTCs).Under the optimum conditions, N-(diphenylmethylene) glycine alkyl esters were obtained in excellent yields in most cases.     

Azaindole derivatives. 66. 1,6-disubstituted 4-methyl-5-cyano-7-azaindolines

A general method was developed for the synthesis of 1,6-disubstituted 4-methyl-5-cyano-7-azalndolines from the readily available ammonium salt of 2,6-dihydroxy-3-(-hydroxyethyl)-4-methyl-5-cyanopyridine through the corresponding N-substituted ammonium salts and N-substituted 2-amino-3-(-hydroxyethyl)-4-methyl-5-cyano-6-hydroxypyridines with treatment of the latter by POCl₃. This method gives a 40% yield of 4-methyl-5-cyano-7-azaindoline compounds containing various aralkyl or alkyl substituents at N-1 and a hydroxy group or halogen atom at C-6 in three steps.For Communication 65, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 84–88, January, 1985.     

Synthesis and Biological Activity Studies of Some Novel Mannich Bases of Benzotriazolyl Triazoles

A series of substituted phenyl methyl piperazine triazolyl benzotriazoles 4a , 4b , 4c , 4d , 4e , 4f , 4g have been synthesized through the Mannich reaction of substituted phenyl triazolyl benzotriazoles 3a , 3b , 3c , 3d , 3e , 3f , 3g . The substituted phenyl triazolyl benzotriazoles were prepared from benzotriazolyl acetohydrazide, where the cyclization was facilitated through ammonium acetate and aryl aldehydes. The IR, ¹H NMR, mass spectral data and elemental analysis were performed to assign the structure. All the newly synthesized compounds were screened for their antimicrobial and antioxidant activity.     

The synthesis of quaternary ammonium salts from ammonium salts and dialkyl carbonate

Quaternary ammonium salts were synthesized from ammonium salts and dialkyl carbonates over an ionic liquid catalyst 1-ethyl-3-methylimidazolium bromide.     

A convenient preparation of N- (arenesulfonyl) sulfoximines by oxidation of N- (arenesulfonyl) sulfilimines with sodium hypochlorite in a two phase system

N-(Arenesulfonyl) sulfilimines can be oxidized to the corresponding sulfoximes in high yields with sodium hypochlorite in an AcOEt-H₂O two phase system in the presence of quaternary ammonium salts as catalysts.     

Photochemical study of tris(benzotriazol-1-yl)methane

Photodecomposition of tris(benzotrizol-1-yl)methane (1) in benzene gives [1-benzotryazol-1-yl-methylidene]-biphenyl-2-ylamine (2) resulting from the loss of the benzotriazolyl radical and nitrogen followed by addition of benzene. Elimination of the second benzotriazolyl radical from 2 provides the biphenyl-2-ylmethyleneamine radical, which affords phenantridine (3) after ring closure. In contrast, the photolysis of 1 in methanol gives a high yield of benzotriazole (4).     

Dealkylation of quaternary 1-alkylazolo[a]pyridinium salts

A convenient method is proposed for the preparation of new derivatives of free heterocyclic bases of imidazo[1,2-a]pyridine, pyrido[1,2-a]benzimidazole, and [1,2,4]triazolo[4,3-a]pyridine series. This method entails the dealkylation of N-(2-cyanoethyl)- or N-benzylazolopyridinium quaternary salts in the presence of bases and reaction with ammonium formate in the presence of Pd/C, respectively.     

不对称诱导(Ⅰ)——手性铵盐催化下芳醛与氯仿的加成反应

本文报导了在十种手性铵盐催化下芳醛和氯仿的不对称诱导反应。同时还对影响产物旋光纯度的因素及其诱导机理进行了讨论。     

Uranyl coordination in ionic liquids: the competition between ionic liquid anions, uranyl counterions, and Cl- anions investigated by extended X-ray absorption fine structure and UV-visible spectroscopies and molecular dynamics simulations

The first coordination sphere of the uranyl cation in room-temperature ionic liquids (ILs) results from the competition between its initially bound counterions, the IL anions, and other anions (e.g., present as impurities or added to the solution). We present a joined spectroscopic (UV-visible and extended X-ray absorption fine structure)-simulation study of the coordination of uranyl initially introduced either as UO2X2 salts (X-=nitrate NO3-, triflate TfO-, perchlorate ClO4-) or as UO2(SO4) in a series of imidazolium-based ILs (C4mimA, A-=PF6-, Tf2N-, BF4- and C4mim=1-methyl-3-butyl-imidazolium) as well as in the Me3NBuTf2N IL. The solubility and dissociation of the uranyl salts are found to depend on the nature of X- and A-. The addition of Cl- anions promotes the solubilization of the nitrate and triflate salts in the C4mimPF6 and the C4mimBF4 ILs via the formation of chloro complexes, also formed with other salts. The first coordination sphere of uranyl is further investigated by molecular dynamics (MD) simulations on associated versus dissociated forms of UO2X2 salts in C4mimA ILs as a function of A- and X- anions. Furthermore, the comparison of UO2Cl(4)2-, 2 X- complexes with dissociated X- anions, to the UO2X2, 4 Cl- complexes with dissociated chlorides, shows that the former is more stable. The case of fluoro complexes is also considered, as a possible result of fluorinated IL anion's degradation, showing that UO2F42- should be most stable in solution. In all cases, uranyl is found to be solvated as formally anionic UO2XnAmClp2-n-m-p complexes, embedded in a cage of stabilizing IL imidazolium or ammonium cations.     

Ferrocenylalkyl azoles: bioactivity,synthesis, structure

The toxicity of ferrocenylethyl benzotriazole ( 1 ) and other ferrocene compounds including ferrocenylmethyl benzimidazoles ( 4,5,6,11 ), ferricenium salts ( 3,9,10 ) and ferrocenylmethyl adenine ( 7 ), was studied. All ferrocene complexes under investigation showed low or medium toxicities. On the basis of an earlier model of chemical carcinogenesis, the antitumor activity of ferrocenylalkyl azoles 1, 8 and ferricenium salts 9, 10 was studied in vivo in the so‐called sub‐capsular test on human tumors. This effectiveness was compared with that of cisplatin. A series of ferrocenylalkyl azoles were synthesized by interacting azoles either with α‐hydroxyalkyl ferrocenes FcC(OH)R₁R₂ in organic solvent in the presence of aqueous HBF₄ in quantitative yields or with trimethyl(aminomethyl)ferrocene iodide in an aqueous‐basic medium in good yields. The X‐ray determinations of molecular and crystal structures of α‐(1‐benzotriazolyl)ethylferrocene ( 1 ) and α‐(1‐naphthatriazolyl)ethylferrocene ( 12 ) were performed. Copyright © 2008 John Wiley & Sons, Ltd.     

Heterocyclic bioantioxidants. 5. Stabilization of 3-nitro-4-coumarinylthiolate by ammonium counterions

Thiolation of 3-nitro-4-chlorocoumarin in the presence of a substituted or unsubstituted ammonium ion can be used to isolate 3-mtro-4-coumarinylthiolates, which are stabilized by the corresponding ammonium cation, while 3-nitro-4-mercaptocoumarin or its potassium or sodium salts decompose during the reaction. Ammonium 3-nitro-4-coumarinylthiolates are decomposed by acids, and the unsubstituted ammonium salt is S-alkylated in the reaction with benzyl chloride.For communication 4, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 459–462, April, 1993.     

Condensation of ammonium ion with acetone

Recrystallization of ammonium anthranilate or ammonium salicylate from acetone-hexane results in conversion of the ammonium salts to diacetoneammonium salts. The reaction is general for the ammonium salts of amino- and hydroxy-substituted benzoic acids, all of which are converted at least in part to diacetoneammonium salts when treated with acetone. Under similar conditions ammonium benzoate is converted to the triacetoneammonium salt. These reactions constitute convenient laboratory procedures for the preparation of diacetoneammonium and triacetoneammonium salts, and explain the frequent incursion of diacetoneamine and triacetoneamine as artifacts when natural systems are extracted with acetone.     

Chemistry of heterocyclic N-oxides and related compounds VI. Reaction of pyridine,dipyridyl, and quinoline N-oxides with ammonia and ammonium salts

The amination of pyridine, quinoline, and 2,3- and 4,4-dipyridyl N-oxides with ammonia and ammonium salts in the presence of p-toluenesulfonyl chloride was studied. 2-Aminopyridine, N-(p-tosyl)-2-aminopyridine, and N-(p-tosyl)-2,2-dipyridyls were obtained in reactions with pyridine N-oxide. 2-Aminoquinoline was obtained in the amination of quinoline N-oxide. Dipyridyl N-oxides do not undergo amination.See [1] for communication V.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 229–232, February, 1976.     

Synthesis of polyfunctionally substituted heteroaromatic compounds via benzotriazolyl chalcones with antimicrobial and antifungal activities

The utility of both 3‐(1‐benzotriazolyl) chalcone derivatives 3a‐c and 2‐(1‐benzotriazolyl)‐1,4‐pentadien‐3‐one (18) in the synthesis of some new 2‐(1H)‐pyridone, pyridine, pyrazole and isoxazole derivatives is reported. Antimicrobial and antifungal screening of some selected examples from the synthesized products were carried out. The structure of the newly synthesized compounds was elucidated by elemental analysis, ir, ¹H and ¹³C nmr investigations.