Benzenesulphenyl Chloride Research Articles

ChemInform Abstract: The Hydroboration of (Trimethylsilyl)ethyne with Dialkylboranes and Its Application to the Syntheses of (E)-1-(Trimethylsilyl)alk-1-enes and 2-(Trimethylsilyl)alk-1-enes.

The reaction of (trimethylsilyl)ethyne 1 with a stoicheiometric amount of dialkylborane 2 proceeds to the monohydroboration stage, giving a mixture of regioisomers, (E)-[2-(trimethylsilyl)-ethenyl]dialkylborane 3 and [1-(trimethylsilyl)ethenyl]dialkylborane 4. In the hydroboration with bulky dialkylboranes, derived from internal alkenes, the former predominates. Successive treatment of the mixture with methyllithium and benzenesulphenyl chloride exclusively affords highly pure (E)-2-alkyl-1-(trimethylsilyl)ethene 6 whose alkyl group migrates from the boron atom, while in the hydroboration with less bulky dialkylboranes, derived from terminal alkenes, the latter predominates. Successive treatment of the mixture with aq. NaOH and iodine exclusively affords highly pure 2-(trimethylsilyl)alk-1-ene 7 whose alkyl group migrates from the boron atom.

Indium-tin oxide anodes modified by self-assembly for light-emitting diodes based on blue-emitting polyfluorenes

We present the electro-optical properties of light-emitting diodes (LEDs) based on two blue-emitting polyfluorenes, with aluminum cathodes and having indium-tin oxide (ITO) anodes modified by self-assembled monolayers (SAM) of benzenesulphenyl chloride derivatives. The modification of ITO surface was confirmed by contact angle measurements. Electroabsorption measurements were used to assess the modification of ITO work function upon SAM formation. We find that the use of a benzenesulphenyl chloride derivative containing a nitro group is as effective at improving LEDs characteristics as the use of a hole-injection layer of well known PEDOT:PSS.

Toxin-Targeted Design for Anticancer Therapy. I: Synthesis and Biological Evaluation of New Thioimidate Heterobifunctional Reagents

In an effort to obtain a more potent and specific immunotoxin for cancer therapy, we designed a series of heterobifunctional linkers characterized by a thioimidate group linked to a S-acetyl thiol (4, 5) or substituted aryldithio group (6-10). These ligands were synthesized by a Pinner-type process from the corresponding nitrile derivatives obtained by thiol-disulphide exchange reaction, reaction with substituted benzene-sulphenyl chloride, or other known procedures. To check the reagent of choice for immunoconjugate preparation, we studied thioldisulphide exchange kinetics between the intermediate nitrile derivatives and cysteine. Among the tested aryldithio derivatives (6-10), we selected ethyl 3-(4-carboxamido-phenyldithio)propionthioimidate (CDPT, 9) for further studies. By analyzing the rate of incorporation of the linkers 4, 5, and 9 in a model immunoglobulin G protein, we found similar results with CDPT 9 and ethyl S-acetyl 3-mercaptopropionthioimidate ester hydrochloride (AMPT, 5) because both reagents showed a linear correlation between the number of introduced thiol groups and factors such as time and protein and reagent concentrations. Comparison of the two acetylthio-derivative ligands 4 and 5 showed that AMPT 5 was more stable toward deacetylation than ethyl S-acetyl 2-mercaptopropionthioimidate ester hydrochloride (AMAT, 4). By comparing the kinetic and biological parameters of seven new thioimidate linkers, we found that two of these (CDPT and AMPT) could be superior ligands for protein-protein conjugation. They offer advantages over the commercially available compounds, such as minimal perturbation of the protein structure, controlled reactivity, and good stability.

A convergent synthesis of methylenomycin B and analogues via selenium assisted cyclopenta-annelation

Reaction of the lithium enolate of 4-chloro-4,5-dimethylhex-5-en-3-one 2 with benzeneselenenyl bromide at –78 °C gives 2,3,5-trimethyl-5-phenylselenocyclopent-2-enone 3. Treatment of compound 3 with 15% H2O2 in methylene dichloride at 0 °C gave methylenomycin B via syn selenoxide elimination. Similarly, the lithium enolate of 7 reacted with benzeneselenenyl bromide to give 2,3-dimethyl-5-phenylselenocyclopent-2-enone 10. Compound 10 can be converted into compound 3via alkylation of its lithium enolate with methyl iodide. The lithium enolate of compound 2 also reacted with benzenesulphenyl chloride and benzoyl chloride to give 2,3,5-trimethyl-5-phenylthiocyclopent-2-enone 13 and 5-benzoyl-2,3,5-trimethylcyclopent-2-enone 14 respectively. Using this cyclization other methylenomycin B analogues were prepared from readily available starting materials.

The hydroboration of (trimethylsilyl)ethyne with dialkylboranes and its application to the syntheses of (E)-1-(trimethylsilyl)alk-1-enes and 2-(trimethylsilyl)alk-1-enes

The reaction of (trimethylsilyl)ethyne 1 with a stoicheiometric amount of dialkylborane 2 proceeds to the monohydroboration stage, giving a mixture of regioisomers, (E)-[2-(trimethylsilyl)-ethenyl]dialkylborane 3 and [1-(trimethylsilyl)ethenyl]dialkylborane 4. In the hydroboration with bulky dialkylboranes, derived from internal alkenes, the former predominates. Successive treatment of the mixture with methyllithium and benzenesulphenyl chloride exclusively affords highly pure (E)-2-alkyl-1-(trimethylsilyl)ethene 6 whose alkyl group migrates from the boron atom, while in the hydroboration with less bulky dialkylboranes, derived from terminal alkenes, the latter predominates. Successive treatment of the mixture with aq. NaOH and iodine exclusively affords highly pure 2-(trimethylsilyl)alk-1-ene 7 whose alkyl group migrates from the boron atom.

A versatile vinyl sulphide synthesis using benzenesulphenyl chloride

Benzenesulphenyl chloride (PhSCl) in CH2Cl2 at −78°C converts thioacetals and thioketals to their α-chlorosulphides which afford vinyl sulphides on elimination. The method is compatible with a range of functionality.

Thio- and seleno-lactonizations of alkynoic acids

Regio- and stereo-specific thio- and seleno-lactonizations of hept-4-ynoic acid (1a), hex-4-ynoic acid (1b), and pent-4-ynoic acid (1c) can be achieved by treatment of benzenesulphenyl chloride and benzeneselenenyl chloride using a hydrogen chloride capture such as triethylamine or a better capture in most cases, 3,4-dihydro-2H-pyrido[1,2a]pyrimidin-2-one. N-Phenylselenophthalimide is also effective for the selenolactonization, although E and Z lactones (E)-(2c; X = Se) and (Z)-(2c; X = Se) are formed from (1c). Cleavage reactions of γ-alkylidene-γ-butyrolactones afford a new preparative method for 4-oxoalkanoic acid derivatives.

Organic synthesis with α-chlorosulphides. Convenient routes to phenylthioacetals from α-diazoketones and alkyl phenyl sulphides via α-chlorosulphides

Summary α-Chloroalkyl phenyl sulphides, derived from either the action of benzenesulphenyl chloride on α-diazoketones or of N-chlorosuccinimide on alkyl phenyl sulphides, are converted into phenylthioacetals on exposure to thiophenol in the presence of zinc chloride.

Electrophilic Additions to Allenes. VIII. The Kinetics and Mechanism of the Addition of Benzenesulphenyl Chloride to Allenes

AbstractThe rates of addition of benzenefulphenyl chloride to 62 alkyl substituted allenes have been determined in methylene chloride solution at 24.5°C. The rates of addition span a range of 3.4 × 103 in reactivity. No correlation with the extended Taft equation or variations thereof was found when the rates of all 62 compounds were considered. Partitioned rate constants, wherein each term reflects the relative propensity for attack upon a given π orbital‐lobe of the allenic system, allows one to demonstrate the specific effect of placing an alkyl group in each of three stereochemically distinct positions. Of note is the observation that while the magnitude of the polar effect of an alkyl group changes with the stereochemical location, this magnitude is a constant for methyl, ethyl and isopropyl. The rates reported herein are interpreted in terms of rate‐limiting formation of alkylidenethiiranium ions.

Light-sensitive elastomers modified by 4-( N-dimethylmaleimido)-benzenesulphenyl chloride

New light-sensitive polymers were prepared by modification of four different elastomers with 4-( N -dimethylmaleimido)-benzenesulphenyl chloride (DMI-BSCI). Polydienes modified by DMI-BSCI form block copolymers. These polymers show a strong increase of the glass transition temperature T g whereby the T g increase of modified poly(octenamer) is much smaller. Higher modified polydienes have two T g . Modified poly(octenamers) show a melting temperature dependence T m on the content of trans double bonds which is characteristic of statistical copolymers. The ratio of rate constants with which trans - and cis -structures in poly(octenamer) are occupied by DMI-BSCI, is k trans k cis = 0.34

Facile regio- and stereo-specific allylic oxidation of gem-dimethyl olefins via addition of benzenesulphenyl chloride. Synthesis of allylic oxygenated terpenes

Novel and facile terminal trans-allylic and internal allylic oxidations of the gem-dimethyl olefin terminus of the terpenoids (1) are described which take place site-, regio-, and stereo-specificially via the same intermediate adduct between benzenesulphenyl chloride and (1). By this method, the allylic oxygenated terpenes (±)-nuciferal (11), (±)-ar-turmerone (12), (±)-ipsdienol (3c), neotorreyol (2e), (±)-6-hydroxydendrolasin (3e), and 6-oxodendrolasin (14) were synthesized.

Synthetic studies on aromatic sesquiterpenoids: synthesis of curcumene ether by olefin cyclisation

The acid-catalysed cyclisation of the olefinic β-hydroxy sulphides (15a) and (15b) gave 3-phenylthiocurcumene ether as a diastereoisomeric mixture [(17) and (18)] together with 5,5-dimethyl-4-phenylthio-1-p-tolylcyclohex-1-ene (16) and 2-methyl-3-(1-methyl-1-phenylthioethyl)-2-p-tolyl-cyclobutan-1-ol (19). The diastereoisomers (17) and (18) were converted into curcumene ether (24). Treatment of the silyl enol ether (7) with benzenesulphenyl chloride yielded 5-phenylthiomethyl-2-[phenylthio(p-tolyl)methylene]tetrahydrofuran (8) and 5-chloro-1,6-bis(phenylthio)-1-p-tolylhexan-2-one (9). 1-p-Tolylhexane-2,5-dione (10) was also synthesised from (5) employing a palladium-catalysed oxidation, and this result constitutes a formal total synthesis of cuparene (11).

Elimination and addition reactions. Part 37. A comparative study of electronic, steric, and solvent effects upon reactivity in additions of benzenesulphenyl chloride to alkenes

Rates of additions of benzenesulphenyl chloride to 35 alkenes in several solvents have been measured, and the products of the reactions have in most cases been identified. Results for arylalkenes broadly confirm previous work, but the responses to solvent change are not uniform throughout. The reactivity of bridged cycloalkenes is substantially greater than that of cycloalkenes, but that of cyclo-pentadiene dimer is anomalously small. For allylic substrates, the correlation of electron density at the double bond with reactivity is shown by a rectilinear relationship between log k and σI. Allyl iodide and allyl alcohol are anomalously more reactive than this correlation would predict; this is accounted for by solvation and by internal solvation effects respectively.

Highly substituted dienes from butyne-1,4-diol. A one-flask synthesis and the mechanism of formation of 3-(N,N-diethylamino)-2-phenylsulphinylbutadiene

When 4-acetoxybut-2-yn-1-ol is treated with benzenesulphenyl chloride and triethylamine, followed by diethylamine, 3-(N,N-diethylamino)-2-phenylsulphinylbutadiene is produced, in a multistep process, in 90% overall yield.

Ketenimine chemistry. Part 1. The reaction of triaryl ketenimines with arenesulphenyl chlorides

Benzenesulphenyl chloride reacts with diphenyl-N-p-tolylketenimine in diethyl ether solution to give N-(1-chloro-2,2-diphenyl-2-phenylthioethylidene)-p-toluidine (IV), via the attack of electrophilic sulphur on the terminal carbon of the ketenimine.

ChemInform Abstract: ELECTROPHILIC CYCLIZATION OF AN OLEFINIC β‐KETO ESTER

AbstractBei Behandlung des Olefins (I) mit dem Selenenylchlorid (II) in Gegenwart von AlCl3 erfolgt Cyclisierung zu (IIIa).

Reaction of bistrifluoromethylaminosulphenyl chloride with hydrocarbon olefins and the synthesis of bistrifluoromethylaminosulphenylarenes

Abstract Reaction of bistrifluoromethylaminosulphenyl chloride with acyclic and alicyclic hydrocarbon olefins at −78 °C in the dark affords 1:1 adducts of type in high yield. Treatment of diaryl disulphides with the N -bromo-amine (CF3)2NBr or of benzenesulphenyl chloride with the mercurial [(CF3)2N]2Hg provide convenient routes to bistrifluoromethylaminosulphenylarenes.

Electrophilic cyclization of an olefinic β-keto ester

Benzeneselenenyl chloride and aluminum chloride or benzenesulphenyl chloride and silica gel initiate an electrophilic cyclization of methyl 7-methyl-3-oxo-7-octenoate to cyclohexyl derivatives. These products of the cyclization reaction have been converted into intermediates of potential use in the synthesis of unusual carotenoids.

Formation of allyl and cyclopropylcarbinyl sulphides in the regiospecific reactions of arenesulphenyl chlorides with allyl- and but-3-enylcobaloximes

Allyl- and substituted-allyl-bis(dimethylglyoximato)pyridinecobalt(III) complexes react regiospecifically with 2,4-dinitrobenzenesulphenyl chloride to give moderate (30–45%) yields of the corresponding rearranged allyl 2,4-dinitrophenyl sulphides. The corresponding rearranged allyl derivative of dimethylglyoxime is a major byproduct. But-3-enylbis(dimethylglyoximeto)pyridinecobalt(III) complexes also react regiospecifically to give cyclopropylmethyl 2,4-dinitrophenyl sulphides. The reactions are interpreted in terms of an electrophilic attack of the sulphur on the γ- and δ-carbon of the allyl- or butenyl-ligand, respectively, with concurrent or subsequent loss of cobaloxime(III), and with concurrent or subsequent cyclisation of the organic ligand in the case of the butenyl complexes. Benzenesulphenyl bromide and chloride react much more slowly and their reaction with allylbis(dimethylglyoximato)pyridinecobalt(III) has been briefly explored.

New syntheses of racemic nuciferal, ar-turmerone, and ipsdienol by a ready regio- and stereo-specific allylic oxidation

A simple regio- and stereo-specific terminal and internal allylic oxidation via benzenesulphenyl chloride addition is reported; using this method racemic nuciferal (11) and ar-turmerone (12) were synthesized from racemic α-curcumene (1a), and racemic ipsdienol (10c) from myrcene (1c).