Novel bis[(E)-1-(halomethyl)-2-chlorovinyl] chalcogenides as starting materials for the efficient synthesis of bis(chloromethylidene)-1,4-dichalcogenanes

An efficient synthesis of novel bis[(E)-1-(halomethyl)-2-chlorovinyl] sulfides and selenides via regio- and stereoselective electrophilic addition of SCl₂ and SeCl₂ to propargyl halides has been developed. The bis(2-chlorovinyl) chalcogenides prepared represent reagents for the synthesis of chalcogen-containing heterocycles and have been used for the synthesis of novel bis(E-chloromethylidene) derivatives of 1,4-dichalcogenanes with various combinations of sulfur and selenium atoms in the ring.     

Stereoselective Synthesis of (Z)‐ and (E)‐Allyl Aryl Sulfides and Selenides from Baylis?Hillman Acetates under Neutral Conditions Using β‐Cyclodextrin in Water

The first example of the stereoselective synthesis of (Z)‐ and (E)‐allyl aryl sulfides and selenides from Baylis? Hillman acetates under neutral conditions in H₂O by supramolecular catalysis involving β‐cyclodextrin is reported. β‐Cyclodextrin can be recovered and reused. The reaction is very efficient in providing allyl aryl sulfides and selenides in good‐to‐excellent yields with clean reaction profiles under mild reaction conditions.     

Hydrothiolation of terminal alkynes with diaryl disulfides and diphenyl diselenide: selective synthesis of (Z)-1-alkenyl sulfides and selenides

A simple, stereoselective and efficient method for the hydrothiolation of terminal alkynes with diaryl disulfides and diphenyl diselenide has been developed. In the presence of CuI, rongalite, and Cs₂CO₃, a variety of disulfides underwent the reaction of terminal alkynes stereoselectively to afford the corresponding (Z)-1-alkenyl sulfides in moderate to excellent yields. It is noteworthy that hydroselenations of 1,2-diphenyldiselane with alkynes are also conducted smoothly to afford (Z)-1-alkenyl selenides in good yields under the standard conditions.     

Through space spin-spin coupling <Superscript>19</Superscript>F-<Superscript>1</Superscript>H as the base for comparative analysis of conformational equilibrium in fluorine-substituted aryl vinyl selenides and sulfides

The analysis of long-range spin-spin coupling ¹⁹F-¹H and the other conformation-dependent parameters of ¹H NMR spectra shows that aryl vinyl selenides like aryl vinyl sulfides exist as mixtures of s-cis and s-trans rotational isomers. The combined data of ¹H and ¹³C NMR spectra reveal the increase in the torsional angle ϑ at the bond X-CH=CH₂ (X = S, Se) in selenides compared to sulfides due to diminished interaction energy of the unshared electron pairs of selenium with the π*-orbitals of the double bond as compared to analogous interaction in sulfides.     

Tetrabutylammonium phenoxide induced reaction of silyl nucleophiles

Reaction of silyl dithiolanes with electrophiles can be efficiently promoted by catalytic amounts of tetrabutylammonium phenoxide (PhONn-Bu₄), leading to a convenient access to functionalized dithiolanes. PhONn-Bu₄ proved effective also in promoting reactions of silylated sulfides such as PhSTMS and HMDST as well as silylated selenides such as PhSeTMS and HMDSS toward epoxides. The present reactivity is also observed on using ILs as reaction media.     

Synthesis of aurocyanide and auricyanide complexes of phosphines,phosphine sulfides and phosphine selenides,and their characterization by IR,far-IR,UV solution,and solid-state NMR spectroscopic methods

A series of aurocyanide and auricyanide complexes of phosphines, phosphine sulfides, and phosphine selenides were synthesized. These new complexes have the general formula [L _n Au(CN) _m ], where L could be Cy₃P, (2-CN-Et)₃P, Me₃PS, Et₃PS, Ph₃PS, Me₃PSe, or Ph₃PSe. Auricyanide was reacted with L at 1?:?2 ratio. Products were characterized using elemental analysis, melting point, UV, IR, far-IR solution, and solid-state NMR spectroscopy. Phosphine ligands cause gold(III) reduction to gold(I); less redox tendency was found for phosphine sulfides and phosphine selenides. Tri-coordinate complexes [L₂AuCN] were produced from phosphine ligands with gold-tetracyanide. IR and UV spectroscopic methods were used to identify gold oxidation state in the synthesized complexes.     

Chlorochalcogenation of acetylenes with benzenesulfen-(or selenen)amides and Tin(IV) chloride

Benzenesulfenamides and benzeneselenenamides reacted with terminal and internal acetylenes (hex-1-yne, phenylacetylene, hex-3-yne, but-2-yne-1,4-diol, and diphenylacetylene) in the presence of SnCl₄ to give the corresponding chloroethenyl sulfides and selenides. From symmetric acetylenes, only E isomers (E)-ArXCR=CClR (X = S, Ar = Ph, 4-ClC₆H₄; R = Et, Ph, HOCH₂; X = Se, Ar = Ph, R = Et) were formed. The reactions of benzenesulfenamide with terminal acetylenes, apart from the corresponding Markownikoff and anti-Markownikoff adducts (PhSCH=CClR and PhSCR=CHCl, R = Bu, Ph) gave ethynyl sulfides PhSC=CR (R = Ph, Bu) and cis/trans-isomeric 1,2-bis(phenylsulfanyl)chloroethenes PhSCR=CClSPh (R = Ph, Bu). The results were interpreted assuming intermediate generation of sulfenyl and selenenyl chlorides via reaction of sulfen-and selenenamides with SnCl₄.     

Palladium-catalyzed alkynylselenation of acetylenedicarboxylates leading to enyne selenides and application to synthesis of multisubstituted aryl selenides

Upon treatment of a mixture of alkynyl selenides and acetylenedicarboxylates with Pd(OAc)₂/P(o-tol)₃/K₂CO₃/H₂O-catalytic system, the alkynylselenation of acetylenedicarboxylates takes place to give the corresponding alkynylvinyl selenides. Furthermore, alkynyl selenides undergo the intermolecular [2+2+2] cycloaddition reaction in the presence of PdCl₂(PPh₃)₂ as a catalyst, affording the corresponding multisubstituted aryl selenides selectively.     

Magnetic properties of chromium sulfide selenides and sulfides

Summary The structural parameters of chromium sulfide selenides are intermediate between those of the sulfides and the selenides. The nature of the dependence of the magnetic properties of the sulfide selenides on temperature and composition has much in common with that for the sulfides. The presence of selenium atoms in the sulfide lattice leads merely to some distortion of the anomalies which are observed for the pure sulfides. In the mixed chalcogenides of chromium, gradual oxidation of the monosulfide by selenium takes place, with the conversion of Cr(II) into Cr(III). The principal contribution to the magnetic moments is made by the spin values, equal to 4.9 _B for Cr(II) and 3.87 _B for Cr(III). The slight increase in the lattice parameters of the sulfide selenides (increase in the Cr–Cr distances) compared with the sulfides leads to a decrease in the exchange interactions in the sulfide selenides compared with the sulfides. This is indicated by the change in the paramagnetic Curie temperature with change in composition.Institute of Catalysis, Siberian Branch, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 14, No. 1, pp. 163–166, January–February, 1973.     

Synthesis of tris(organylthioethyl)phosphines and their derivatives on the basis of the reaction of phosphine with vinyl sulfides

Phosphine generated from the red phosphorus in the system KOH-H₂O-toluene adds regio- and chemoselectively to vinyl sulfides under radical initiation conditions with the formation of tris(2-organylthioethyl)phosphines, which are easily oxidized by elemental sulfur and selenium to the corresponding phosphine sulfides and phosphine selenides in 54–78% yield. The obtained adducts are split when treated with sodium amide in THF to give trivinylphosphine and trivinylphosphine chalcogenides.     

A Novel Synthesis of Benzyl Sulfides and Selenides via Sm/BiCl3 System in Aqueous Media

Benzyl sulfides and selenides are synthesized via reaction of benzyl bromide with disulfides and diselenides promted by Sm/BiCl₃ system in aqueous media in moderate to good yields.     

Regioselective Addition of Dithiophosphinic Acids to Vinyl Sulfides and Selenides: An Efficient Route Toward Functional Dithiophosphinates

Earlier unknown S‐[1‐(organosulfanyl)ethyl]‐ and S‐[1‐(organoselenyl)ethyl] dithiophosphinates were synthesized in 85–97% yields by regioselective addition of dithiophosphinic acids to diverse vinyl sulfides and selenides under mild conditions (ambient temperature, Et₂O, 3 h).     

Indium-mediated cleavage of diphenyl diselenide and diphenyl disulfide: efficient one-pot synthesis of unsymmetrical diorganyl selenides, sulfides, and selenoesters

A convenient and efficient method was developed for the synthesis of alkyl phenyl selenides, sulfides, and selenoesters in one-pot reaction by using indium metal. The reaction showed the selectivity for tert-alkyl, benzylic, and allylic halides over primary and secondary alkyl halides. For the reaction of primary and secondary alkyl iodides and bromides, the yields of selenides were improved by the addition of a catalytic amount of iodine.     

A new approach to the synthesis of 2-vinylthiophenes and selenophenes; competition between free radical and anionic cycloaromatization of bridged di- and tetrapropargylic sulfides and selenides

A series of unknown di- and tetrapropargylic sulfides and selenides have been prepared. In the presence of t-BuOK in dry THF these compounds underwent isomerization to the corresponding diallenes, followed by a tandem anionic cyclization and aromatization to 2-vinylthiophene or selenophene derivatives. Some mechanistic studies indicated competition between free radical and anionic cycloaromatization. The latter is influenced by the nature of the bridging heteroatom, substitution of the allenyl group and base concentration.     

Copper-catalyzed synthesis of β-haloalkenyl chalcogenides by addition of dichalcogenides to internal alkynes and its application to synthesis of (Z)-tamoxifen

A copper-catalyzed synthesis of β-haloalkenyl sulfides or selenides was carried out by addition of dichalcogenides and tetrabutylammonium halides to internal alkynes. The present reaction anti- and regio-selectively afforded the corresponding alkenyl chalocogenides, and took advantage of both organochalcogenide-groups on dichalcogenide. Furthermore, the reaction under oxygen atmosphere could employ thiols. The use of the procedure could easily synthesize (Z)-tamoxifen from diphenyl acetylene in three steps.     

A convenient and efficient copper-catalyzed synthesis of unsymmetrical and symmetrical diaryl chalcogenides from arylboronic acids in ethanol at room temperature

A simple and convenient approach for the synthesis of unsymmetrical diaryl chalcogenides (Te, Se, and S) has been developed by copper-catalyzed cross-coupling reaction of organoboronic acid with diaryl dichalcogenide in ethanol using NaBH₄ in air or oxygen. The present methodology is highly practical for the synthesis of unsymmetrical diaryl tellurides with various functionalities such as –NO₂, –F, –Br, and –COOH that have been obtained in good to excellent yields. Methodology is also effective for the synthesis of unsymmetrical diaryl selenides and sulfides. Moreover, symmetrical diaryl selenides have also been obtained from arylboronic acids using elemental selenium powder under optimized reaction conditions. The use of NaBH₄ is the key for the development of milder reaction conditions, which enable the construction of unsymmetrical diaryl chalcogenides from boronic acid substrates in ethanol at room temperature.     

Fluorescence properties of nanosized sulfides

The absorption spectra of nanosized sulfides and selenides (ZnS, CdS, CuS, Cu₂S, AgS, In₂S₃, SnS, PbS, Sb₂S₃, FeS, CoS, NiS, CdSe, and Ag₂Se) showed one absorption band with a maximum at wave-lengths shorter than 300 nm. The UV fluorescence spectra of all of these nanosized sulfides in a polyvinyl alcohol film contained maxima at 380–440 nm. Nanosized sulfides are thus characterized by a very large (up to 15000 cm⁻¹) Stokes shift of fluorescence. In a polyvinyl alcohol film, a decrease in the concentration of cadmium sulfide from 0.05 to 0.002 M led to a threefold increase in the fluorescence intensity. The dependence of the degree of fluorescence buildup on the sulfide concentration is nearly linear. An increase in sulfide concentration to more than 5 × 10⁻³ M in solution led to a complete coagulation of particles.     

Komplexe der Ionen Ni2+ und Co2+ mit Sulfiden (Seleniden) di-, tri- und tetratertiärer Arsane

Complexes of the Ni²⁺ and Co²⁺ Ions with Sulfides and Selenides of di-, tri-, and tetratertiary Arsanes The reaction of the sulfides (selenides) of di-, tri- and tetra-tertiary arsanes with the salts CoCl₂ · 6 H₂O respectively Ni(ClO₄)₂ · 6 H₂O results in the formation of chelat complexes, in which the metal ions are tetrahedrally surrounded by the ligands. The UV spectra of the complexes are discussed.     

Synthesis and crystal structure of [CODRh(SC6F5)]2

The metathetical reaction of Pb(SC₆F₅)₂ with the halogen bridged compounds [L RhCl]₂ where L are chelating dienes, afforded the chalcogen bridged analogs. Subsequent reactions with a variety of ligands including phosphines, arsines, sulfides and selenides, have shown important differences between sulphur and halogen bridged complexes, attributable to the fluorinated moiety. Some of these reactions will be discussed and the crystal structure of [COD Rh(SC₆F₅)]₂ will be described.     

Stoichiometry and physical properties of ternary molybdenum chalcogenides MxMo6X8 (X = S,Se; M = Li,Sn, Pb)

Chemical and electrochemical insertion of Li at room temperature, as well as insertion of lead and tin at moderate temperatures (500°C), into the binary phase Mo₆X₈ forms ternary molybdenum chalcogenides M_xMo₆X₈ (X = S, Se). Crystallographic parameters, superconducting properties, and magnetic susceptibility are reported. The stoichiometry x for lead and tin is shown not to exceed x = 1, while for Li, x can reach approximately 4.0. For the lead and tin sulfide series, the hexagonal lattice parameters and superconducting critical temperatures (T_c) are invariant to changes in the nominal composition of 0.8 < x < 1.2, while both an increase in T_c and a small decrease in c_h is observed for the selenides; a narrow homogeneity range exists near x = 1 below 500°C for both these sulfides and selenides, the single-phase region being somewhat larger in the selenides. In contrast, several single-phase regions and large unit cell changes are observed in Li_xMo₆X₈ (0 < x < 3.2). Magnetic susceptibility measurements of the lithiated compounds at x ～ 3.2 reveals a structural phase transition at 140 and 185 K for the sulfide and selenide, respectively; but neither superconducts down to 1.5 K. At lower lithium concentration near x ～ 1.0, the T_c of the sulfide is raised from that of Mo₆S₈ (1.8 K) to 5.2 K but the T_c of Mo₆Se₈ (6.5 K) is depressed to 3.9 K.