The reaction of phenyliodonium bis-(phenylsulfonyl)methylide with some thiophenes

The title iodonium ylide gives with thiophenes C-H insertion products of the C(SO₂Ph)₂ group and with benzothiophenes transylidation products.     

New hetero-annelation reactions using N-[bis-(methylthio)-methylene]-amino and related reagents

Summary Reaction of acyclic (B _1–3) and cyclic (R _4–5)BMMA (=N-[b is-(methylthio)-methylene]-amino) reagents withGewald-type thiophene derivatives (2,3) led to annelation of pyrimidine moieties. Thus, linear thiazolo- or thiazino- and pyrrolo-, pyrido- or azepino-fused thiopyrano[4,3:4,5]thieno-[2,3-d]pyrimidines (5 and6) as well as the angular imidazo-fused thiopyrano[4,3:4,5]thieno-[2,3-d]pyrimidine8 were easily obtained from one-pot reactions in good yields.on leave from Chemistry Department, Minia University, El-Minia, Egypt     

Metallation reactions. XXXVI. A study on the metallation of (methylthio)‐ and (methylsulfonyl)thiophenes

Methylthio‐ and methylsulfonyl thiophenes were polymetallated by n‐buthyllithium and superbase (LICKOR) in one‐step. 2 ‐(Methylthio)thiophene was bimetallated in 5 and in alpha to the methylthio sulfur atom by superbase. 3‐(Methylthio)thiophene was bimetallated in both 2 and 5 positions by the organolithium and trimetallated in these two positions and in alpha to the thioethereal sulfur atom by superbase. 3‐(Methylsulfonyl)thiophene was bimetallated in 2 and in alpha to the sulfonyl sulfur atom by the organolithium while the 2 ‐(methylsulfonyl)thiophene underwent degradation in the same conditions.     

Synthesis and some reactions of tris (pentafluorophenyl) antimony compounds

(C₆F₅)₃Sb has been found to react with interhalogens and halo-pseudohalogens, IX(X = Cl, Br, N₃ and NCO), pseudohalogen (SCN), and elemental sulphur to give oxidative addition products (I–VI). (C₆F₅)₃SbS(VI) may also be prepared by the reaction of (C₆F₅)₃SbCl₂ with H₂S. Metathetical reactions of (C₆F₅)₃SbCl₂ with appropriate metallic salts yield covalent pentacoordinate disubstituted products (V, VII–XII) of the general formula, (C₆F₅)₃SbY₂ (Y = NCS, NCO, ?ONCMe₂, ?ONCMePh $\text{?NCO(CH}{}_2\text{)}{}_2\text{C}$O and p-NO₂C₆H₄OCO). Treatment of (C₆F₅)₃SbCl₂ with aqueous NaN₃ gives the binuclear oxo-bridge compound, [(C₆F₅)₃SbOSb(C₆F₅)₃](N₃)₂·(III) and (IV) are also accessible by displacement reaction of (I) or (II) with the corresponding metallic salt. Molecular weight, conductance measurements, and IR spectra on the new organoantimony(V) derivatives have been obtained.Reductive cleavage reactions of (C₆F₅)₃SbS with hexaaryldileads, Ar₆Pb₂(Ar = Phenyl, p-tolyl) produce (C₆F₅)₃Sb and the corresponding bis(triaryllead) sulphide but treatment of (C₆F₅)₃SbX₂(X = NCO, Cl) with Ar₆Pb₂ gave Ar₄Pb and Ar₂PbX₂ together with (C₆F₅)₃Sb.(C₆F₅)₃SbCl₂ and bis(triorganotin)sulphides undergo exchange of anionic groups.     

Synthesis and spectral characteristics of bis- and tris(Δ2-pyrazolinyl) benzenes

The electronic absorption and fluorescence spectra and the relative quantum yields of 1,3-bis(3-aryl-5-phenyl-²-pyrazolin-1-yl)- and bis- and tris(1-phenyl-5-aryl-²-pyrazolin-3-yl) benzenes were measured and are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1394–1397, October, 1974.     

The mass spectra of some tris(trimethylsilyl)acylsilanes and tris(trimethylsilyl)silanes

While tris(trimethylsilyl) alkanoylsilanes fragment in the acylsilane form yielding [(Me₃Si)₃SiCO]⁺ by α-cleavage, the molecular ions of their aryl counterparts rearrange to ionized silaethenes prior to cleavage, paralleling known photochemical behaviour. Sila-allyl type structures are attributed to the stable [M? Me˙]⁺ ions obtained by subsequent cleavage. Metastable ion characteristics reveal the identity of the structures of the monomeric silaethene ions obtained from one of the aroylsilanes and a 1,2-disilacyclobutane. The non-compliance of the alkanoylsilanes with their photochemical behaviour is attributed to a preferred elimination of the stable alkyl radical (R˙) from the molecular ions. Several polysilanes display abundant odd-electron ions which may possess a disilene structure.     

Synthesis and structure of tetrakis(isopropylimino)bis-[tris(dimethylamino)silylamino]alane

A novel cage-type compound tetrakis(isopropylimino)bis[tris(dimethylamino)silylamino]alane, H₆Al₆(NⁱPr)₄[NSi(NMe₂)₃]₂, (1), was prepared by reaction of tris(dimethylamino)silylamine H₂NSi(NMe₂)₃ with poly(isopropyliminoalane) (HAlNⁱPr)₆. The molecular structure of 1 was determined and discussed on the basis of FTIR, NMR and X-ray crystallographic analysis.     

Metallation reactions XXVII.: Metallation of (methylthio)anilines

The metallation reactions of (methylthio)anilines with organolithium reagents and with the butyllithium–potassium tert-butoxide superbasic mixture are here described. The results show that the para isomer when treated with butyllithium gave a mixture of products with no selectivity. Using tert-butyllithium or superbases we obtained the substitution of the thiomethyl hydrogen. Moreover, superbase allowed to prepare the disubstituted product with the new groups in the thiomethyl and in ortho to this group. On the other side, both ortho and meta isomers were lithiated at the thiomethyl carbon by butyllithium and the other reagents. Starting from the unalkylated amine we prepared through three successive one-pot monometallations N,N-disubstituted amines with equal or different groups and bearing an alkylthio chain as long as wanted.     

High-yield syntheses of 2,3-disubstituted furans and thiophenes

The course of lithiation of furan- and thiophene-2-carboxylic acids is critically dependent on the identity of the lithium base allowing high-yielding syntheses of 2,3- and 2,5-disubstituted thiophenes: the proposed use of a trimethylsilyl blocking group to control metallation in the furan acid provides a useful route to 2,3-disubstituted furans.     

Preparation and reactions of some sterically hindered silanols, including [tris(trimethylsilyl)methyl]silanetriol

The silanol TsiSiMe₂OH (Tsi = (Me₃Si)₃C) has been made by hydrolysis of the iodide TsiSiMe₂I in H₂O/dioxane or H₂O/Me₂SO. It has been shown to react with some acid chlorides RCOCl (R=Me, Et, CICH₂ Ph, 4-O₂NC₆H₄, and 3,5- (O₂N)₂C₆H₃) and anhydrides (RCO)₂O (R = Me, CF₃, or Ph) to give the carboxylates TsiSiMe₂OCOR, and with SO₂Cl₂ to give TsiSiMe₂OSO₂Cl. The triol TsiSi(OH)₃ has been made by treatment of TsiSiH(OH)I with H₂O/Me₂SO at 150°C or with a mixture of aqueous AgClO₄ and an organic solvent. The triol has been shown to react with RCOCl (R = Me, Et, or Ph) or (RCO)₂O (R = Ph) to give the corresponding TsiSi(OCOR)₃, with (CF₃CO)₂O to give TsiSi(OH)₂(OCOCF₃), and with a mixture of Me₃SiCl and AgClO₄ in benzene or one of Me₃Sil and (Me₃Si)NH to give TsiSi(OSiMe₃)₃. The triol is unusually stable, but decomposes at its m.p. of 285–290°C.     

Complexation of niobium(V) with some bis-(β-diketones)

The complexes of niobium(V) with 2-phenyl-1,1,3,3-tetraacetylpropane and 2-phenyl-1,3-diacetyl-1,3-dibenzoylpropane were investigated by IR, UV,¹H-NMR, and magnetic measurements. Together with analytical data and determination of molecular weights a trimeric structure is proposed for both 1:1 complexes.

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Komplexierung von Niob(V) mit einigen Bis(-diketonen)

Zusammenfassung Es wurden die Komplexe von Niob(V) mit 2-Phenyl-1,1,3,3-tetraacetylpropan und 2-Phenyl-1,3-diacetyl-1,3-dibenzoylpropan untersucht. IR-, UV- und¹H-NMR-Spektren sowie magnetische Messungen zusammen mit analytischen Daten und Molekulargewichtsbestimmungen ergaben für beide 1:1 Komplexe eine trimere Struktur.

     

Synthesis of some tris(trimethylsilyl)germyl compounds

A variety of compounds containing the tris(trimethylsilyl)germyl group were prepared and characterized spectroscopically. Photolysis of adamantoyltris(trimethylsilyl)germane failed to yield the isomeric germene: in CCl₄ the photolysis appeared to occur by a Norrish type 1 process.     

Some reactions of tris(trimethylstannyl)- and tetrakis(trimethylstannyl)-methane

With a variety of electrophilic reagents reaction occurs exclusively at the CH₃Sn bonds of [(CH₃)₃Sn]₄C and [(CH₃)₃Sn]₃CH. While the inner SnC bonds remain intact, methyl groups may be progressively cleaved off, one from each of the trimethylstannyl groups; in the case of bromine a second Me group may be cleaved from each of the SnMe₂Br groups. The various products were identified by ¹H, ¹³C and ¹¹⁹Sn NMR spectroscopy.     

Reactions of tris(2-pyridyl)phosphines and tris(2-pyridyl)phosphine oxides with some electrophiles

Treatment of tris(2-pyridyl)phosphine or tris(2-pyridyl)phosphine oxide with electrophiles such as chlorine, bromine, deuterium chloride, or benzenediazonium chloride gave unusual coupling products, i.e., 5-chloro-, 5-bromo-, 5-deuterio-, or 5-phenylazo-2,2′-bipyridyls, respectively, as a major coupling product in each case. This is considered to be the result of electrophilic substitution on a pyridyl ring in a pentacovalent phosphorane intermediate formed in each reaction. © 1997 John Wiley & Sons, Inc. Heteroatom Chem 8: 439–449, 1997     

A general synthesis of methyl aldulosonates using tris (methylthio) methyl lithium as the ester anion equivalent

A general procedure is described for the conversion of aldonolactones to their corresponding methyl 2-aldulosonates.