Selenonium Salts Research Articles

Carbon-carbon bond formation under aqueous reaction conditions using sulfonium and selenonium salt electrophiles

Methylation of relatively acidic (pK a<13) carbon nucleophiles occurs at neutral pH in aqueous media using suitably substituted methyl sulfonium and selenonium salt electrophiles.

ChemInform Abstract: Asymmetric Induction in the Alkylation of Enolate Anion with the Optically Active Selenonium Ions.

AbstractMethyl phenyl selenide (I) is ethylated to form the racemic selenonium salt (IIIa) which is optically resolved via the D‐camphor sulfonates.

ChemInform Abstract: Dopamine Agonists: Effects of Charged and Uncharged Analogues of Dopamine.

Dopamine, at physiological pH, may exist as either an uncharged amine or a charged ammonium species. In order to gain insight as to which species is better suited for interaction with the dopamine receptor, we have synthesized dopamine analogues in which the nitrogen atom is replaced with a neutral methyl sulfide, a neutral methyl selenide, a charged dimethylsulfonium iodide, and a charged dimethylselenonium iodide. These analogues were tested for their ability to inhibit the K+-stimulated release of [3H]acetylcholine from striatal slices. At 30 microM concentration, the charged sulfonium and selenonium salts possessed significant agonist activity while the corresponding neutral species were inactive, suggesting that a charged species is optimal for dopamine agonist activity. In addition, the methyl sulfide was converted into the corresponding sulfoxide and sulfone; however, neither of these oxidation products possessed significant activity as dopaminergic agonists.

Asymmetric Induction in the Alkylation of Enolate Anion with the Optically Active Selenonium Ions

Abstract Alkylation of the enolate anion of 2-methoxycarbonyl-1-indanone with optically active dialkylphenyl selenonium salt resulted in the formation of optically active C-alkylated products. Absolute configuration of the optically active selnonium ion was estimated on the basis of the asymmetric alkylation and CD spectra.

ChemInform Abstract: First Synthesis of Oxoselenonium Salts.

Die bisher nicht bekannten Triaryl-oxoselenonium-Salze (II) werden erstmals durch Oxidation der Selenonium-Salze (I) mit m-Chlorperbenzoesäure in alkalischem Medium hergestellt.

Synthesis and biodistribution of radioiodinated selenonium salts: Potential myocardial imaging agents

Abstract(o‐[125I]iodobenzyl)benzylmethylselenonium tetrafluoroborate (1) and (o‐[125I]iodobenzyl)dibenzylselenonium tetrafluoroborate (2) were synthesized by methylation and benzylation of o‐[125I]iodobenzyl benzyl selenide respectively. The starting compound o‐iodobenzyl benzyl selenide was radioiodinated with sodium [125I]iodide by melt‐exchange in a sealed ampoule maintained at 75°C for 12 hours, with subsequent chromatographic purification yielding the pure compound in a radiochemical yield of 33.0% and specific activity of at least 68.0 mCi/mmol. Tissue distribution studies of compounds 1 and 2, performed in rats, showed that the labelled compounds accumulated rapidly in the heart. The maximum heart‐to‐blood ratios for compounds 1 and 2 were 4.2:1 and 4.4:1 compared to that of 2.0:1 for previously synthesized [75Se]Trimethylselenonium Iodide (3).

FIRST SYNTHESIS OF OXOSELENONIUM SALTS

Abstract Triaryloxoselenonium salts have been synthesized for the first time by oxidation of selenonium salts with peroxybenzoate anion.

ChemInform Abstract: SOLVENT EFFECTS ON KINETICS AND REACTION MECHANISMS. THE FORMATION OF SULFONIUM AND SELENONIUM SALTS

Chemischer InformationsdienstVolume 15, Issue 7 Preparative Organic Chemistry ChemInform Abstract: SOLVENT EFFECTS ON KINETICS AND REACTION MECHANISMS. THE FORMATION OF SULFONIUM AND SELENONIUM SALTS E. MACCARONE, E. MACCARONESearch for more papers by this authorG. PERRINI, G. PERRINISearch for more papers by this author E. MACCARONE, E. MACCARONESearch for more papers by this authorG. PERRINI, G. PERRINISearch for more papers by this author First published: February 14, 1984 https://doi.org/10.1002/chin.198407133Read 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 onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume15, Issue7February 14, 1984 RelatedInformation

Solvent effects on kinetics and reaction mechanisms. The formation of sulphonium and selenonium salts

Second-order rate constants and activation parameters for the methylation of methyl phenyl sulphide and methyl phenyl selenide by dimethyl sulphate have been measured in 14 aprotic solvents covering a wide range of dielectric constants. The same reactivity order is observed with both substrates in the various solvents. The analysis of the medium effects on the reactivity was performed by the Koppel–Palm multi-parameter approach. The results indicate that the polarization and electrophilicity of the solvents are responsible for the rates of both reactions. The higher reactivity of methyl phenyl selenide has been ascribed to the higher polarizability and softness of the selenium atom in comparison with the sulphur atom.

Exchange reactions in olefin oxide-phenyl ?-hydroxyalkyl selenide system

Exchange reactions proceed in the olefin oxide-phenylβ-hydroxyalkyl selenide system with the probable intermediate involvement of the selenonium salt.

2,3] Sigmatropic rearrangement of ylides derived from benzylic selenonium salts

2,3] Sigmatropic rearrangement of ylides derived from benzylic selenonium salts

ChemInform Abstract: BASE TREATMENT OF BENZYLIC SELENONIUM SALTS. (2,3) SIGMATROPIC REARRANGEMENTS VS. NUCLEOPHILIC DISPLACEMENT

AbstractBenzylphenylselenid (I) reagiert mit Methyliodid zu einem Gleichgewichtsgemisch der Verbindungen (I)‐(V).

Nitro ylides. 7. Synthesis and some reactions of alkyl-substituted selenonium nitro ylides

1. Stable dialkylselenonium nitro ylides have been synthesized. 2. In reactions with strong electrophilic reagents (halogens, hydrogen halides, and N-halo imides), the dialkylselenonium nitro ylides behave like their diphenylselenonium analogs: cleavage of the intermediate selenonium salt by the counterion and by a second molecule of electrophile takes place exclusively at the\(Se--C_{NO_2 } \) bond. 3. A study has been made of the ability of iodonium nitro ylides to transfer a nitromethylene fragment to sulfides and selenides to form the corresponding sulfonium and selenonium ylides. 4. The feature distinguishing the dialkylselenonium nitro ylides from their diaryl analogs is their ability to undergo a transylidation reaction with thiourea.

Base treatment of benzylic selenonium salts. [2,3] Sigmatropic rearrangements vs. nucleophilic displacement

Treatment of certain benzylic selenonium salts with a variety of bases resulted in nucleophilic attack to yield either an alkylation or a benzylation of the base, while the use of sodium amide in liquid ammonia as base generated a selenonium ylide which gave ortho substitution of the benzyl group via[2,3]sigmatropic rerrangement.

ChemInform Abstract: REACTION OF β‐OXOPHOSPHONIUM, SULFONIUM, AND SELENONIUM SALTS WITH SULFOXIDES AND SELENOXIDES

Chemischer InformationsdienstVolume 10, Issue 26 Preparative Organic Chemistry ChemInform Abstract: REACTION OF β-OXOPHOSPHONIUM, SULFONIUM, AND SELENONIUM SALTS WITH SULFOXIDES AND SELENOXIDES N. N. MAGDESIEVA, N. N. MAGDESIEVASearch for more papers by this authorV. A. DANILENKO, V. A. DANILENKOSearch for more papers by this author N. N. MAGDESIEVA, N. N. MAGDESIEVASearch for more papers by this authorV. A. DANILENKO, V. A. DANILENKOSearch for more papers by this author First published: June 26, 1979 https://doi.org/10.1002/chin.197926129Read 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, Issue26June 26, 1979 RelatedInformation

A new general route to olefins from selenides

Olefins including alkylidenecyclopropanes are readily prepared from the corresponding selenides by reaction of base on the corresponding selenonium salt. The reaction also applies to cyclopropylsulfides.

A new preparation of triarylsulfonium and -selenonium salts via the copper(II)-catalyzed arylation of sulfides and selenides with diaryliodonium salts

A new preparation of triarylsulfonium and -selenonium salts via the copper(II)-catalyzed arylation of sulfides and selenides with diaryliodonium salts

Volatile selenium in higher plants the production of dimethyl selenide in cabbage leaves by enzymatic cleavage of Se-methyl selenomethionine selenonium salt

The volatile selenium compound produced by cabbage (Brassica oleracea var. Capitata) when cultured on media containing either selenite or selenate is dimethyl selenide, (CH3)2 Se. The dimethyl selenide arises from enzymatic cleavage of a Se-methyl selenomethionine selenonium compound. re]19730424

Cleavage of Se-ethylselenomethionine selenonium salt by a cabbage leaf enzyme fraction

An enzyme fraction from leaves of cabbage ( Brassica oleracea var. capitata) has been shown to cleave Se-methylselenomethionine selenonium bromide to dimethyl selenide and homoserine. The enzyme had maximal activity at pH 7.8. The enzyme fraction was shown also to cleave S-methylmethionine sulfonium salt to dimethyl sulfide and homoserine. A mechanism is proposed for the production of dimethyl selenide in higher plants by enzymatic cleavage of the selenonium salt. Both of these compounds have been identified in cabbage plants grown on media containing either selenite or selenate.

Ceric ion equilibrium in aqueous acetic acid

Ceric ion equilibrium in aqueous acetic acid