Aryldiazonium Ions Research Articles

Formation of N‐Cyclopropylhydrazones by Azo Coupling of Cyclopropyldiazonium with Aliphatic CH Acids.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Formation of N-cyclopropylhydrazones by azo coupling of cyclopropyldiazonium with aliphatic CH acids

Decomposition of N-cyclopropyl-N-nitrosourea under the action of K2CO3 or KOH containing 15—20% of H2O at 0—7 °C gives rise to cyclopropyldiazonium, which reacts with some β-diketones, methyl cyanoacetate, or malonodinitrile to form the corresponding cyclopropylhydrazones. The latter compounds are analogous to products of azo coupling and isomerization of aryldiazonium ions with the above-mentioned substrates. These transformations provide the first example of azo coupling of the cyclopropyldiazonium ion in the series of activated aliphatic CH acids.

Space-time distribution of γ-glutamyl transferase activity in Agaricus bisporus

γ-Glutamyl transferase is involved in the biosynthesis of two characteristic γ-glutamyl compounds occurring in Agaricus bisporus: agaritine and γ-glutaminyl-4-hydroxybenzene. Agaritine was shown to be a precursor of potential toxic aryl diazonium ions and γ-glutaminyl-4-hydroxybenzene was demonstrated to be one of the main substrates implicated in mushroom browning. γ-G;utamyl transferase activity was measured in various tissues of A. bisporus fruitbodies at different developmental stages and in mycelium grown on synthetic and compost media. Gills and skin, which exhibit the highest levels of γ-glutamyl amino acids, also present the highest levels of γ-glutamyl transferase activity. Stipe base tissue, which is characterised by a lack of agaritine and the presence of its hydrolysis product hydroxymethylphenylhydrazine, also exhibits high levels of γ-glutamyl transferase activity. Thus, in the gills and in the skin, γ-glutamyl transferase could be mainly involved in the synthesis of γ-glutamyl derivatives and, in the stipe base, in the hydrolysis of agaritine. γ-Glutamyl transferase activity measured in mycelia was rather low but significantly greater in mycelium grown on compost medium than on synthetic medium. These results are in agreement with the lack of γ-glutaminyl-4-hydroxybenzene in mycelium grown on artificial medium. Cap flesh and stipe tissues show the lowest γ-glutamyl transferase activity. The elucidation of the role of γ-glutamyl transferase in the synthesis of one of the main substrates for mushroom browning opens new perspectives in attempts to optimise post-harvest quality.

Space-time distribution of γ-glutamyl transferase activity inAgaricus bisporus

γ-Glutamyl transferase is involved in the biosynthesis of two characteristic γ-glutamyl compounds occurring in Agaricus bisporus: agaritine and γ-glutaminyl-4-hydroxybenzene. Agaritine was shown to be a precursor of potential toxic aryl diazonium ions and γ-glutaminyl-4-hydroxybenzene was demonstrated to be one of the main substrates implicated in mushroom browning. γ-G;utamyl transferase activity was measured in various tissues of A. bisporus fruitbodies at different developmental stages and in mycelium grown on synthetic and compost media. Gills and skin, which exhibit the highest levels of γ-glutamyl amino acids, also present the highest levels of γ-glutamyl transferase activity. Stipe base tissue, which is characterised by a lack of agaritine and the presence of its hydrolysis product hydroxymethylphenylhydrazine, also exhibits high levels of γ-glutamyl transferase activity. Thus, in the gills and in the skin, γ-glutamyl transferase could be mainly involved in the synthesis of γ-glutamyl derivatives and, in the stipe base, in the hydrolysis of agaritine. γ-Glutamyl transferase activity measured in mycelia was rather low but significantly greater in mycelium grown on compost medium than on synthetic medium. These results are in agreement with the lack of γ-glutaminyl-4-hydroxybenzene in mycelium grown on artificial medium. Cap flesh and stipe tissues show the lowest γ-glutamyl transferase activity. The elucidation of the role of γ-glutamyl transferase in the synthesis of one of the main substrates for mushroom browning opens new perspectives in attempts to optimise post-harvest quality.

Solvent Dependence of the Reaction of (eta(5)-C(5)Me(5))Ir(CO)(2) with Aryldiazonium Ions. Synthesis and Characterization of Mono- and Diiridium Carbonyl Complexes Including the X-ray Structures of [{(eta(5)-C(5)Me(5))Ir(CO)}(2)(1-eta(1)-1,2-eta(2)-p-C(6)H(4)OMe)][BF(4)] and [(eta(5)-C(5)Me(5))(CO)(2)Ir-Ir(CO)(Cl)(eta(5)-C(5)Me(5))][BF(4)

Reaction of CpIr(CO)(2) (3, Cp = eta(5)-C(5)Me(5)) with [N(2)Ar][BF(4)] (Ar = p-C(6)H(4)OMe) in acetone at -78 degrees C affords the nitrogen extrusion product [CpIr(CO)(2)(Ar)][BF(4)] (5), but in dichloromethane it yields a dinuclear product [Cp(CO)(2)Ir-Ir(Cl)(CO)Cp][BF(4)] (6). By carrying out this very reaction in ethanol solution, a nitrogen-retained product [CpIr(CO)(OEt)(NHNAr)][BF(4)] (7) is obtained, containing an aryldiazene ligand. Deprotonation of 7 gives quantitatively the neutral doubly-bent aryldiazenido complex CpIr(CO)(OEt)(N(2)Ar) (8). The IR nu(CO) absorptions measured for the dinuclear compound 6 indicate no bridging carbonyl, but a (13)C NMR study in solution shows that 6 is stereochemically nonrigid at ambient temperature; its three carbonyl ligands are all involved in a fast exchange process, and this process is frozen at -86 degrees C. Exchange of the CO groups via a terminal-bridging-terminal process accompanied by rotation about the Ir-Ir axis is suggested. The molecular structure of 6 in the solid state has been established by single crystal X-ray crystallographic analysis and is consistent with the solution spectra. By reaction of [N(2)Ar][BF(4)] with the dinuclear complex [CpIr(CO)](2) (4) in acetone, the complex [{CpIr(CO)}(2)(1-eta(1)-1,2-eta(2)-p-C(6)H(4)OMe)][BF(4)] (9) with a rare sigma,pi-bridging aryl group has been obtained and crystallized. The molecular structure containing an asymmetric bridging aryl group is established for 9 in the solid state by a single crystal X-ray crystallographic analysis. However, the identical (1)H NMR features observed at ambient temperature and -90 degrees C in solution (i.e., a singlet resonance for the two Cp ligands and a symmetric AA'BB' pattern for the p-C(6)H(4)OMe) indicate a static or time-averaged symmetrical molecular geometry for 9. Compound 6 crystallizes in the monoclinic space group P2(1)/c with a = 10.583(2) Å, b = 14.256(3) Å, c= 16.818(4) Å, beta = 95.91 (2) degrees, V = 2523.9 Å(3), and Z = 4. Refinement yielded R(F)() = 0.027 and R(w)(F)() = 0.033 for 3299 observed reflections (I(o) >/= 2.5sigma(I(o))) of 4427 unique reflections. Compound 9 crystallizes in the monoclinic space group P2(1)/n with a = 11.695(2) Å, b = 19.911(3) Å, c= 12.539(2) Å, beta = 96.54(1) degrees, V = 2900.8 Å(3), and Z = 4. Refinement yielded R(F)() = 0.025 and R(w)(F)() = 0.035 for 3444 observed reflections (I(o) >/= 2.5sigma(I(o))) of 4526 unique reflections.

EPR study of the arylnitro anion radicals formed in the reaction between some aminoarenes, sodium nitrite and ascorbate

By EPR spectroscopy it was shown that stable free radicals are formed at room temperature in :reaction mixtures containing sodium nitrite and aminoarenes such as 4-aminobenzoic acid, sulfanilic acid, 3,5dimethoxyaniline 3,4,5-trimethoxyaniline, 3,5-dibromo-4-aminobenzenesulfonic acid, aminobenzene, 4fluoroaniline or 4-methoxybenzenediazonium ions together with ascorbic acid when first dissolved in water followed by the addition of NaOH to an alkaline pH. The radicals appeared without any previous irradiation with UV light. The EPR spectra exhibited an interaction of the unpaired electron with one nitrogen nucleus and the hydrogen nuclei of the parent aminoarenes. By use of [15N]nitrite it was found that the nitrogen atom of the radicals was derived from the nitrite ion. It is suggested that the radicals are arylnitro anion radicals ArNO2˙–. The reaction involves the formation of aryldiazonium ions ArNN (acidic conditions) in the reaction with nitrite, followed by their reduction to aryl radicals Ar˙ in the reaction (alkaline conditions) with ascorbic acid. The radicals Ar˙ combine with nitrite ions to give the observed arylnitro anion radicals ArNO2˙–.

Communication: The Reductive Coupling of Carbohydrate Radicals with Diazonium Ions: a New Access to 2-Amino-2-Deoxy Glycosides

The oxidative coupling of glycals with alcohols is an efficient procedure for creating an α-glycosidic bond. It can be triggered by an “I+”-reagent (iodonium di-sym-collidine perchlorate1 or N-iodosuccinimide2) and occurs in a 1,2-diaxial fashion through a presumed 1,2-iodonium ion intermediate leading to 2-deoxy-2-iodo-α-glycosides. This iodoglycosylation allows the preparation of 2-deoxy-α-glycosides by reductive deiodination with tributylstannane3 or nickel boride.4 Considering the behavior of good leaving groups at C-2 of α-D-mannopyranosides,5 the displacement of iodine by oxygen or nitrogen functions through SN2-type reactions would be difficult or impossible, unless performed with internal nucleophiles.6 In contrast, a C-2 radical can be easily trapped by electron-deficient olefins7 or nitrogen monoxide8 giving access to C-2 branched carbohydrates and oximes, respectively. Nucleophilic radicals have also been trapped by aryldiazonium ions in a reversible manner to give azo radical cations.9 In the presence of a reducing agent (Ti3+, Fe2+, Cr2+, V2+), the equilibrium is shifted towards the azo compound:

Diazo Coupling of Metal Chelates of 2,4-Pentanedione

Metal 1,3-diketonates are known to undergo many electrophilic substitutions typical of aromatic compounds because of the quasi-aromatic C 3 O 2 M ring systems present in these chelates. Although the aryldiazonium ion is a dominant electrophile (its coupling with free 1,3-diketones is an electrophilc substitution), reports are scanty on its reaction with metal-chelated 1,3-diketones. In this paper, we report the electrophilic substitution of the phenyldiazonium ion at 2,4-pentanedionates of aluminium(III), chromium(III), copper(II) and palladium(II)

ChemInform Abstract: The Reaction of Aryldiazonium Ions (II) with 5‐Alkyl‐4,6‐pyrimidinediols (I): A Novel Pyrimidine to 1,2,4‐Triazine Ring Transformation.

ChemInformVolume 21, Issue 7 Heterocyclic Compounds ChemInform Abstract: The Reaction of Aryldiazonium Ions (II) with 5-Alkyl-4,6-pyrimidinediols (I): A Novel Pyrimidine to 1,2,4-Triazine Ring Transformation. D. T. HURST, D. T. HURST School Life Sci., Kingston Polytech., Kingston upon Thames, Surrey KT1 2EE, UKSearch for more papers by this authorN. S. JENNINGS, N. S. JENNINGS School Life Sci., Kingston Polytech., Kingston upon Thames, Surrey KT1 2EE, UKSearch for more papers by this author D. T. HURST, D. T. HURST School Life Sci., Kingston Polytech., Kingston upon Thames, Surrey KT1 2EE, UKSearch for more papers by this authorN. S. JENNINGS, N. S. JENNINGS School Life Sci., Kingston Polytech., Kingston upon Thames, Surrey KT1 2EE, UKSearch for more papers by this author First published: February 13, 1990 https://doi.org/10.1002/chin.199007218AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume21, Issue7February 13, 1990 RelatedInformation

A mechanistic study of the reaction between aryldiazonium ions and imidazoles

Whereas the neutral form of pyrrole reacts with 4-nitrobenzenediazonium ions, the parallel reaction of imidazole involves the anion. The involvement of the imidazole anion is based on kinetic evidence, pressure studies, and MNDO calculations. N-Methylation affects not only the kinetics of reaction but also the products. With the neutral form of imidazole it is suggested that the predominant reaction with an aryldiazonium ion is reversible attack on a ring nitrogen.

The reaction of aryl diazonium ions with 5-alkyl-4,6-pyrimidinediols: A novel pyrimidine to 1,2,4-triazine ring transformation

The reaction of diazotised arylamines with 5-methyl and 5-ethylpyrimidine-4,6-diol gives 6-alkyl-2-aryl-1,2,4-triazin-5(2 H )-ones.

ChemInform Abstract: Syntheses of Isocyanides at the Metal. Part 10. Radical Alkylation of Cyano Complexes. Part 3. α‐Halogenoalkyl Isocyanides.

AbstractThe cyano chromium complexes (I) and (IV) are alkylated via a radical mechanism initiated by aryldiazonium ions to give the α‐halogenoalkyl isocyanides (III), (VI) or (VIII).

Volumes of activation for anion-diazonium ion recombination

Anion-cation recombination reactions between aryldiazonium ions and anionic nucleophiles have volumes of activation which are small or even negative against expectations of considerably positive values resulting from release of electrostricted solvent. Various interpretations of these results are considered.Volumes of activation for reactions: X-C6H4-N2+ + Nu− → X-C6H4-NN-Nu have been measured by high pressure stopped-flow kinetics. Values of (X, Nu−, solvent ΔV≠/cm3 mol−1, ) are: H,N3−, water, +2.2; H, HSO3−, water,−9.1; H,SO3=,−8.9, water; p-NO2, PhSO2−, −1.7 water; p-OMe, p-nitrobenzoate, DMSO, −15; . None of the reactions show the large positive values expected for ion-neutralisations. Various interpretations are discussed.

Reactions of 3-aryl-1-(tetrazol-5′-yl)triazenes with some electrophiles: mercury derivatives and fragmentations: a new route to aryl diazocyanides

Treatment of 3-aryl-1-(tetrazol-5′-yl)triazenes (4) with lead tetra-acetate resulted in a fragmentation to aryl diazocyanides. The triazenes (4) and their monomethyl derivatives when treated with mercuric acetate and phenylmercury hydroxide gave stable mercuri compounds with mercury bonded at N-3 and the tetrazole N-2′. The reaction of the triazenes with acetic anhydride resulted in acetylation of the triazene unit with fragmentation to aryl diazonium ions and 5-acetamidotetrazoles. These reactions are discussed and the 13C n.m.r. spectra of the products are analysed.

An 131I iodotamoxifen: No carrier added iodination via a diazonium salt

An 131I-labeled iodotamoxifen has been prepared by a “no carrier added” procedure in a 40% radio-chemical yield via an aryl diazonium ion salt intermediate. Two approaches were used to produce high specific activity iodotamoxifen: nonaqueous solvents and copper catalysis. The use of the nonaqueous solvent acetonitrile has proved successful while neither copper powder, copper-bronze, copper(I)oxide nor Cu(II) sulphate showed any catalytic effects.

Substituent effects on 13C- 15N spin couplings and 13C chemical shifts in benzenediazonium ions

Similar trends are observed for 1J( 13C- 15N) values for a series of aryldiazonium tetrafluoroborates and comparable anilinium fluorosulfonates. Contributions from resonance structures involving double-bond character in the CN bond are judged to be relatively unimportant in the ground state structure of aryldiazonium ions.

Interaction of aryldiazonium salts with some schiff-base complexes of cobalt and ruthenium

Abstract The interaction of aryldiazonium ions with some Schiff-base complexes of cobalt and ruthenium have been studied. With cobalt, one-electron oxidation of [Co(II)Salen] occurred; with [Co(I)Salen] the corresponding Co(III)-aryl complexes were isolated. In the case of ruthenium oxidation also occurs, [Ru(Salen)(CO)py] gave the corresponding monocation. The results, especially for ruthenium, are in contrast to the stabilisation of both nitrosyl and aryldiazonium adducts in analogous porphyrin complexes.

An investigation of the reduction of aryldiazonium ions by hydrazines

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn investigation of the reduction of aryldiazonium ions by hydrazinesWilliam T. Evanochko and Philip B. ShevlinCite this: J. Am. Chem. Soc. 1979, 101, 16, 4668–4672Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://doi.org/10.1021/ja00510a037RIGHTS & PERMISSIONSArticle Views174Altmetric-Citations5LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (570 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: SOLID PHASE PHOTOLYSIS: PHOTOCLEAVAGE OF A STERICALLY HINDERED AZOXYBENZENE INTO ARYLDIAZONIUM AND PHENOXIDE IONS

Chemischer InformationsdienstVolume 10, Issue 4 Preparative Organic Chemistry ChemInform Abstract: SOLID PHASE PHOTOLYSIS: PHOTOCLEAVAGE OF A STERICALLY HINDERED AZOXYBENZENE INTO ARYLDIAZONIUM AND PHENOXIDE IONS D. DOEPP, D. DOEPPSearch for more papers by this authorD. MUELLER, D. MUELLERSearch for more papers by this author D. DOEPP, D. DOEPPSearch for more papers by this authorD. MUELLER, D. MUELLERSearch for more papers by this author First published: January 23, 1979 https://doi.org/10.1002/chin.197904097Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue4January 23, 1979 RelatedInformation

Complexation of aryldiazonium ions by polyethylene glycols and their ethers

Complexation constants for interactions of p-tert -butylbenzenediazonium tetrafluoroborate with polyethylene glycols and their mono- and dimethyl ethers in 1,2-dichloroethane are reported. For polyethylene glycols of molecular weights 1000 and 1500 and their dimethyl ethers complexation constants with the aryldiazonium ion are 12–18% of that for the crown ether 18-crown-6.