bluuebunny/crossref_metadata_2025 huggingface dataset:
Lewis acid properties of phosphenium and arsenium cations: Study of their adducts with pyridine
Authors: Payrastre Corinne , Madaule Yves , Wolf Jean Gérard , Kim Tag Chong , Mazières Marie‐Rose , Wolf Robert , Sanchez Michel
Published: January 2005

In the growing field of dicoordinated Group 15 cations, the quantitative study of the Lewis acid properties of phosphenium or arsenium cations has not yet been undertaken. Moreover, there are only a few described examples of syntheses of arsenium cations. The aim of this work is to enhance this series and to develop a quantitative comparative study of their complexation with Lewis bases such as pyridine. The observation of the 13C NMR C‐4 variation in the pyridine ring is a good probe to obtain the apparent equilibrium constant Kc and thus a Lewis acidity scale. Phosphenium cations are more acidic than arsenium cations.
Gas phase thermolysis of allylphosphines, kinetic study
Authors: Martín G. , Ocando‐Mavarez E. , Osorio A. , Laya M. , Canestrari M.
Published: January 2005

Diallylphenyl, allylbenzylphenyl and allylmethylphenyl phosphines were pyrolized in a stirred‐flow reactor at 380–429°C/7‐20 torr, using toluene as carrier gas. The reaction products were propene, 1‐phospha‐1,3‐butadiene, 1‐phospha‐1,2‐diphenylethylene and 1‐phosphaethylene.

The phospha‐alkenes formed evolve into cyclo addition products. The propene elimination reaction showed first‐order kinetics with rate coefficients following the Arrhenius equations: Diallylphenylphosphine:
k(s−1) = 1010.57 ± 0.31 exp(‐143 ± 4 kJ/mol.RT)
Allylbenzylphenylphosphine:
k(s−1) = 109.71 ± 0.47 exp(‐135 ± 6 kJ/mol.RT)
Allylbenzylphenylphosphine:
k(s−1) = 109.61 ± 0.61 exp(‐144 ± 9 kJ/mol.RT)
A six‐center cyclic transition state unimolecular reaction mechanism, consistent with the above Arrhenius parameters, is proposed for the propene elimination reaction.
Reaction of lithium diphenylphosphonium di(methylide) with carbonic acid derivatives. A novel access to polyfunctional unsaturated esters and amides
Authors: Cristau Henri‐Jean , Perraud‐Darcy Anne , Ribeill Yves
Published: January 2005

The lithium diphenylphosphonium di(methylide) Ph2 P(CH2)2 Li 1 readily attacks cyclic carbonates, carbamates, and thiocarbamates, resulting in “pseudo‐acylation” products, after a ring‐opening step. Thus, new stabilized ylides are prepared, which can be used in situ as carbonyl olefination reagents towards aldehydes. This procedure is a new one‐pot method for the synthesis of (E)‐vinylic esters and amides, bearing a free ω‐hydroxyl group. When a thiocarbamate is the initial substrate for 1, a Michael‐type cyclization occurs, following the Wittig olefination, resulting in the one‐pot preparation of 7‐membered heterocycles.
Aminophosphaethyne (PCNH2) and its isomers
Authors: Ermolaeva Ludmila , Ionkin Alexey
Published: January 2005

The potential energy hypersurface of the conversion of aminophosphaethyne (1) to 1‐aza‐3‐phosphaallene (2) has been studied with the MNDO method. The interconversion includes five intermediate species. The structure and energy of 1 and its isomers produced by a hydrogen shift have been calculated also with ab initio molecular orbital theory by a split valence basis set including a polarization function at the P atom. The results reveal that all the isomers are equilibrium structures. The ab initio calculation predicts the carbenaazaphosphirane 3 to be the intermediate lowest in energy. It is suggested that a carbene (3), phosphinidene (4) or azaphosphirene (5) are responsible for the 1‐aza‐2,4‐diphosphole formation.
Dialkyltin derivatives of dicarboxylic acids: Synthesis, characterization and in vitro antitumor properties
Authors: Gielen Marcel , Bouâlam Mohammed , Meriem Abdelkader , Mahieu Bernard , Biesemans Monique , Willem Rudolph
Published: January 2005

Diorganotin derivatives of dicarboxylic acids, including diethyltin propene‐1,3‐dicarboxylate, diethyltin homophthalate, and di‐n‐butyltin tetrafluorophthalate, were tested in vitro against two human tumor cell lines, MCF‐7, a mammary tumor, and WiDr, a colon carcinoma. Most of these display lower inhibition doses ID50 than cis‐platin. The synthesis and characterization of the last three compounds by Mössbauer spectroscopy, 1H, 13C and/or 119Sn NMR and mass spectrometry, are also presented.
Attempted 1,3‐trimethylsilyl migration in Me3SiPSNR system
Authors: Ionkin A. S. , Ignat'Eva S. N. , Litvinov I. A. , Naumov V. A. , Arbuzov B. A.
Published: January 2005

A dimer of thioxo‐N‐t‐butylimino(trimethylsiloxy)‐phosphorane 5 has been prepared by reaction of tris(trimethylsilyl) phosphine with N‐sulfinyl‐N‐tert‐butylamine. The structure of 5 has been confimed by X‐ray analysis data. 1‐Aza‐2‐thia‐3‐phosphaallene 1, thiaphosphaziridine 3, iminophosphine P‐sulfide 4 are postulated as intermediates of the reaction studied.
Synthesis and characterization of the double cluster complexes of [(μ‐RS)(μ‐MeAs)Fe2(CO)6]2—the crystal and molecular structure of [μ‐iPrS)(μ‐MeAs)Fe2(Co)6]2
Authors: Song Li‐Cheng , Hu Qing‐Mei , He Jun‐Lin , Wang Ru‐Ji , Wang Hong‐Gen
Published: January 2005

By the reaction of [(μ‐RS (μ‐CO)Fe2 (CO)6] [Et3NH] with MeAsI2, six new double cluster complexes, [(μ‐RS) (μ‐MeAs)Fe2(CO)6]2 (R = Et, Pr, iPr, Bu, C5H11, Ph), were synthesized. The structure of the iPr analog was determined by single crystal X‐ray diffraction techniques. Crystal data were as follows: monoclinic, P21/n, Z = 4, a = 14.475(4), b = 13.825(3), c = 17.225(5) Å, β = 112.44(2)°, V = 3186 Å3, R = 0.037, and Rw = 0.052.
Reaction of heterocyclic ketene aminals with aryl isothiocyanates and synthesis of sulfur containing heterocycles therefrom
Authors: Huang Zhi‐Tang , Yang Jing‐Kui
Published: January 2005

Heterocyclic ketene aminals reacted with aryl isothiocyanates to give products of addition to the β‐carbon. By oxidative cyclization of these addition products by the action of bromine, isothiazole‐fused heterocycles or benzothiazole‐substituted heterocyclic ketene aminals were formed according to the influence of the different substituents.
Generation and characterization of new sulfenate salts via ipso‐substitution of azaheterocyclic sulfoxides
Authors: Furukawa Naomichi , Konno Yasuo , Tsuruoka Masayuki , Ogawa Satoshi
Published: January 2005

New stable sulfenate salts, sodium 2‐pyridinesulfenate 9a and sodium 2‐(3‐trimethylsilyl)pyridinesulfenate 9b, were prepared by the ipso‐substitution reactions of azaheterocyclic sulfoxides (1c/3a and 4a, respectively) with sodium ethoxide or sodium butanethiolate under mild conditions and were characterized by physical and spectroscopic properties. The FT‐IR spectra of compounds 9a and 9b showed characteristic SO absorptions at 870 and 890 cm−1, respectively. These sulfenate salts were converted rapidly to the corresponding sulfinate salts on contact with oxygen. A number of other sulfenates were prepared and trapped by alkylation to give sulfoxides (as were 9a and 9b).
Trinitromethanide and tricyanomethanide salts restricted to C, H, N, and O atoms
Authors: Gunasekaran Ananthakrishnan , Boyer Joseph H.
Published: January 2005

Trinitromethane combined with oximes of cyclopentanone, cyclohexanone, and diphenylcyclopropenone and with melamine and two 1,3‐dialkyl‐2,4‐dialkylimino‐1,3‐diazetidines to give simple trinitromethanide salt adducts. Tricyanomethane added to diphenylcyclopropenone oxime to give hydroxylamino‐2,3‐diphenylcyclopropenylium tricyanomethanide.
Alkoxylation of hydridophosphorane. II. Reaction of hydridophosphorane with benzenesulphenic esters
Authors: Liu Lunzu , Li Guowei , Huang Mingzhi , Cao Ruzhen , Zhang Shukui
Published: January 2005

The spirophosphorane 4 underwent reaction with a series of benzene‐sulphenic esters 3 to give the corresponding isolable alkoxyphosphoranes. The reactivities of benzenesulphenic esters 3 in this reaction were seen to be dependent on steric hindrance of the R groups. The yields of alkoxyphosphoranes were influenced by the reaction temperature. The probable mechanism was suggested in terms of experimental observations.
The chemistry and structure of the P(O)NC(O) system. Part 3. Preparation of O,O‐diethyl‐N‐acylphosphoramidates and their reactions with electrophiles
Authors: Bauermeister Sieglinde , Modro Tomasz A. , Zwierzak Andrzej
Published: January 2005

Six O, O‐diethyl‐N‐acylphosphoramidates (1a‐f) were synthesized. The reactions of their conjugate bases with haloalkanes were studied. The N/(phosphoryl)O/(carbonyl)O regioselectivity varied greatly, depending on the substrate, the haloalkane, the base, and other reaction conditions. The earlier [17] reaction of N‐formyl substrate 1a that led to the N‐phosphorylated formamidine was extended to other substrates 1. Again, the yields and the selectivity depended strongly on the structure of a substrate.
Simple synthesis of endo‐2‐bromo‐5‐thiabicyclo[2.1.1]hexane
Authors: Block Eric , Naganathan Sriram
Published: January 2005

A brief synthesis of endo‐2‐bromo‐5‐thiabicyclo [2.1.1]hexane (9) has been developed involving conversion of 3‐cyclopentenol (6) to 3‐thioacetoxycyclopentene (7), bromination of this giving trans‐1,2‐dibromo‐4‐thioacetoxycyclopentane (8), and treatment of the latter with base. Compound 9 is oxidized to its S‐oxide 10 and S, S‐dioxide 11. Comparative 13C and 1H NMR data are given for 9–11.
Pyrromethene–BF2 complexes as laser dyes: 2
Authors: Boyer Joseph H. , Haag Anthony M. , Sathyamoorthi Govindarao , Soong Mou‐Ling , Thangaraj Kannappan , Pavlopoulos Theodore G.
Published: January 2005

Pyrromethene–BF2 complexes (P–BF2) 7 were obtained from α‐unsubstituted pyrroles 5 by acylation and condensation to give intermediate pyrromethene hydrohalides 6 followed by treatment with boron trifluoride etherate. Conversion of ethyl α‐pyrrolecarboxylates 4 to α‐unsubstituted pyrroles 5 was brought about by thermolysis in phosphoric acid at 160°C, or by saponification followed by decarboxylation in ethanolamine at 180°C, or as unisolated intermediates in the conversion of esters 4 to pyrromethene hydrobromides 6 by heating in a mixture of formic and hydrobromic acids. Addition of hydrogen cyanide followed by dehydrogenation by treatment with bromine converted 3,5,3′,5′‐tetramethyl‐4,4′‐diethylpyrromethene hydrobromide 9 to 3,5,‐3′,5′‐tetramethyl‐4,4′‐diethyl‐6‐cyanopyrromethene hydrobromide 6bb, confirmed by the further conversion to 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐cyanopyrromethene–BF2 complex 7bb on treatment with boron trifluoride etherate.

An alternation effect in the relative efficiency (RE) of laser activity in 1,3,5,7,8‐pentamethyl‐2,6‐di‐n‐alkylpyrromethene–BF2 dyes depended on the number of methylene units in the n‐alkyl substituent, ‐(CH2)nH, to give RE ≥ 100 when n = 0,2,4 and RE 65, 85 when n = 1,3. (The RE 100 was arbitrarily assigned to the dye rhodamine 6G). The absence of fluorescence and laser activity in 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐isopropylpyrromethene–BF2 complex 7p and a markedly diminished fluorescence quantum yield (Φ 0.23) and lack of laser activity in 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐cyclohexylpyrromethene–BF2 complex 7q were attributed to molecular nonplanarity brought about by the steric interference between each of the two bulky 8‐substituents with the 1,7‐dimethyl substituents. An atypically low RE 20 for a peralkylated dye without steric interference was observed for 1,2,6,7‐bistrimethylene‐3,5,8‐trimethylpyrromethene–BF2 complex 7j. Comparisons with peralkylated dyes revealed a major reduction in RE 0–40 for the six dyes 7u–z lacking substitution at the 8‐position.

Low laser activity RE was brought about by functional group (polar) substitution in the 2,6‐diphenyl derivative 7I, RE 20, and the 2,6‐diacetamido derivative 7m, RE 5, of 1,3,5,7,8‐pentamethylpyrromethene–BF2 complex (PMP–BF2) 7a and in 1,7‐dimethoxy‐2,3,5,6,8‐pentamethylpyrromethene–BF2 complex 7n, RE 30. Diethyl 1,3,5,7‐tetramethyl‐8‐cyanopyrromethene‐2,6‐dicarboxylate–BF2 complex, 7aa, and 1,3,5,7‐tetramethyl‐2,6‐diethyl‐8‐cyanopyrromethene–BF2 complex, 7bb, offered examples of P–BF2 dyes with electron withdrawing substituents at the 8‐position. The dye 7aa, λlas 617 nm, showed nearly twice the power efficiency that was obtained from rhodamine B, λlas 611 nm.
Synthesis and stability of 2,4,6‐trinitrobenzylamine
Authors: Sitzmann Michael E. , Adolph Horst G.
Published: January 2005

2,4,6‐Trinitrobenzylamine was synthesized via 2,4,6‐trinitrophenylacetic acid and 2,4,6‐trinitrobenzyl isocyanate. The title compound decomposes at room temperature but forms a stable hydrochloride and acetyl derivative.
Synthesis of some sulfur‐containing spiro‐pyrimidinetriones, pyrazolidinediones, and isoxazolidinediones
Authors: Reddy D. Bhaskar , Padmavathi V. , Seenaiah B. , Padmaja A.
Published: January 2005

Novel sulfur‐containing spiro compounds such as 7,11‐diaryl‐9‐thia‐2,4‐diazaspiro [5,5] undecane‐1,3,5‐trione 9,9‐dioxides (2), 6,10‐diaryl‐8‐thia‐2,3‐diazas‐piro[4,5]decane‐1,4‐dione‐8,8‐dioxides (3) and 6,10‐diaryl‐2‐oxo‐8‐thia‐3‐azaspiro [4,5] decane‐1,4‐dione‐8,8‐dioxides (5) have been prepared by the condensation of 4‐dimethoxycarbonyl/diethoxycarbonyl‐3,5‐diaryl‐1‐thiane 1,1‐dioxides (1) with urea, hydrazine hydrate, and hydroxylamine hydrochloride, respectively. The N‐substituted derivatives (4 and 6) of 3 and 5 have also been prepared by acylation and nitrosation. The structures of 2, 3, and 5 were established by IR, 1H NMR, and 13C NMR spectral studies, respectively.
Reduction of O‐methyl oxime ethers of conjugated cyclohexenones with aluminum hydride
Authors: Zaidlewicz Marek , Uzarewicz Ireneusz G.
Published: January 2005

The reduction of representative O‐methyl oxime ethers 1–4 with aluminum hydride in tetrahydrofuran yielded allylic amines and saturated aziridines as the main products. The stereochemical course of the reduction to aziridines depends on the oxime ether configuration. Thus, E–3, E–4 and Z–3, Z–4 gave 15, 16 and 21, 22, respectively, with high stereoselectivity. Higher reactivity of Z than E isomers was utilized for the preparation of pure E isomers of oxime ethers from E, Z mixtures.
Crystal and molecular structures and the absolute configuration of O,Se‐dimethyl‐N‐(1‐phenylethyl)phosphoramidoselenoates
Authors: Wieczorek Michał W. , Błaszczyk Jarosław , Krzyżanowska Bożenna
Published: January 2005

The structural investigation of two enantiomers of the phosphoroorganic selenium‐containing compound [(+)C10H16NO2PSe (1) and (−)C10H16NO2PSe (1′)] was carried out. The absolute configuration at the P and C3 atoms was found to be R for compound 1 and, respectively, S for compound 1′.
The reaction of pentasubstituted 3‐hydroxy‐1,2‐dioxolanes (hemiperketals) with trivalent phosphorus compounds: Synthesis of β‐hydroxy ketones
Authors: Baumstark Alfons L. , Vasquez Pedro C. , Chen Yaxiong
Published: January 2005

The reaction of a series of 4,4‐dimethyl‐3,5,5‐(R3, R2, R1)‐3‐hydroxy‐1,2‐dioxolanes 1a–d [1a (R1 = R2 = R3 = Me); 1b (R1 = R2 = Me, R3 = Ph); 1c (R1 = Ph, R2 = R3 = Me); 1d (R1 = R3 = Ph, R2 = Me)] with trimethyl phosphite or triphenylphosphine produced the β‐hydroxy ketones, 2a–d [(R1R2C(OH)CMe2‐COR3)], and the corresponding phosphoryl compounds in high yield. The reactions were slow (∼24 hours), requiring excess of the trivalent phosphorus compounds for optimum results. The reaction was found to be of the second order overall, first order in peroxide and in phosphorus reagent. Triphenylphosphine was found to be more reactive than trimethyl phosphite. Formal substitution of a phenyl group for a methyl group on the hemiperketals yielded a reduction of reactivity of ∼2.4‐fold at the 3‐position but an increase in reactivity (∼1.5‐fold) at the 5‐position. The rate constants for tautomerization of 1c in benzene were determined. The activitation parameters for reaction of 1c with triphenylphosphine in benzened6 were determined [ΔH‡ = 15.0 ± 1.5 kcal/mol; ΔS‡ = −21.7 eu; ΔG‡ = 21.7 kcal/mol; k34° = 2.4 × 10−3 M−1 s−1]. The data are consistent with direct insertion of the phosphorus compounds into the peroxide bond to yield phosphorane intermediates. Rapid intramolecular hydrolysis of the intermediates would produce the β‐hydroxy ketones and phosphoryl compounds.
Photochemical fragmentation of the 2‐phosphabicyclo[2.2.2]octa‐5,7‐diene ring system as a versatile method for generating 3‐coordinate methylene phosphine oxides and sulfides
Authors: Quin Louis D. , Tang Jian‐Sheng , Quin Gyöngyi S. , Keglevich György
Published: January 2005

1,6‐Dihydrophosphinine 1‐oxides with 4‐chloro‐3(or 5)‐methyl substituents give cycloadducts with dimethyl acetylenedicarboxylate having the 2‐phosphabicyclo[2.2.2]octa‐5,7‐diene ring system that can be fragmented easily on irradiation with ultraviolet light (254 nm). The phosphorus‐containing bridge is released as a derivative of the 3‐coordinate methylene phosphine oxide species, RP(O)CH2. This species is too reactive to observe but is readily trapped by an addition reaction with alcohols to give phosphinates (R = alkyl or aryl) or phosphonates (R = O‐alkyl). These experiments constitute the first demonstration of the existence of ROP(O)CH2. Phosphoryl oxygen in the cycloadducts has been replaced by sulfur, and these sulfides fragment smoothly on irradiation. The 3‐coordinate species PhP(S)CH2 has been generated by other workers, but the species ROP(S)CH2 was generated here for the first time. The power of the bicyclic fragmentation route for the generation of a variety of 3‐coordinate P‐methylene derivatives is made evident by this study.
Dihalo derivatives of 3‐coordinate hypervalent phosphorus compounds
Authors: Arduengo Anthony J. , Breker Johannes , Davidson Fredric , Kline Michael
Published: January 2005

The preparation of 1,1‐difluoro‐3,7‐di‐tert‐butyl‐2,8‐dioxa‐1‐phosphabicyclo[3.3.0]octa‐3,6‐diene (Dit‐BuADPO·F2)from hexafluoropropylene oxide (HFPO) and 3,7‐di‐tert‐butyl‐2,8‐dioxa‐1‐phosphabicyclo[3.3.0]octa‐2,4,6‐triene (DitBuADPO) is described. The solid state structure of DitBuADPO·F2 shows an unusual square pyramidal geometry. The structural and spectroscopic properties of DitBuADPO·F2 are compared with other oxidized derivatives of DitBuADPO that contain 5‐coordinate phosphorus.
Selective formation of trichloro(2‐oxoalkyl)telluriums and dichlorobis(2‐oxoalkyl)telluriums from tellurium tetrachloride and enol silyl ethers
Authors: Han Li‐Biao , Kambe Nobuaki , Ikura Masahiro , Ryu Ilhyong , Sonoda Noboru
Published: January 2005

The reactions of TeCl4 with 1 or 2 equivalents of enol silyl ethers yielded trichloro(2‐oxoalkyl)telluriums or dichlorobis(2‐oxoalkyl)telluriums, respectively, in high yields. Stepwise addition of two different enol silyl ethers to TeCl4 in CH2Cl2 led to the selective formation of unsymmetrical dichlorobis(2‐oxoalkyl)telluriums.
The nature of Krause's adducts: The structure of the 1:1 adduct of triphenylborane with sodium metal
Authors: Eisch John J. , Dluzniewski Tomasz , Behrooz Mohammad
Published: January 2005

Triphenylborane (7) undergoes reductive dimerization with sodium metal in diethyl ether solution to form a yellow solid (3) having the empirical composition Ph3B· Na· (C2H5)2O. By 1H NMR spectroscopy, 3 has now been shown to have the structure depicted. By the
chemical structure image
action of heat or strongly donor ethers, 3 rearranges into 6, whose structure was likewise determined by 1H and 11B NMR spectroscopy and by deuteriodeboronation with DOAc. Prolonged reaction of sodium metal with 7 or with diphenylboron chloride (8) in DME leads to biphenyl precursors, sodium tetraphenylborate (9), and sodium phenylborohydrides. All these results can be reconciled by the formation of the radical–anion 10 from 7 and its subsequent coupling or fragmentation. The coupling of 10 to form 3 and the rearrangement of 3 to yield 6 shows that there is a striking parallel in behavior between the isoelectronic (Ph3B·)− and the triphenylmethyl radical (Ph3C·). In this light, the solution of the “hexaphenylethane riddle” is also applicable to the solution of the “hexaphenyldiborate dianion riddle,” which was posed by the discovery of Krause's adduct over 68 years ago.
α‐Trifluoromethyl substituted α‐aminoacids and α‐hydroxyacids with organometallic moieties in the side chain [1,2]
Authors: Sewald Norbert , Gaa Karl , Burger Klaus
Published: January 2005

Several strategies for the synthesis of α‐trifluoromethyl substituted α‐aminoacids and α‐hydroxyacids with organometallic moieties in the side chain are described. The preparative potential of organometallic substituents (organosilicon, organotin, and organocobalt moieties) offers a convenient methodology for the synthesis of highly functionalized α‐aminoacid and α‐hydroxyacid derivatives.
X‐Ray crystallographic study of a 1,3,2‐dioxaphosphorinane dimer containing five‐coordinated phosphorus in the 12‐membered ring
Authors: Huang Yande , Sopchik Alan E. , Arif Atta M. , Bentrude Wesley G.
Published: January 2005

Attempted preparation of phosphorane 9 with a 1,3,2‐dioxaphosphorinane ring attached diequatorially to phosphorus led to a mixture of products from which was isolated 12‐membered ring phosphorane 10, formally the dimer of 9, in low yield (22%). An X‐ray crystal structure of 10 revealed a highly symmetrical molecule with trigonal bipyramidal geometry at both phosphorus atoms. The 12‐membered ring is attached to phosphorus diequatorially. The ring is strongly puckered about phosphorus with an equatorial O‐P‐O angle of 110°. The chemical shift equivalence of the CH2O resonances in the 1H NMR spectrum of 10 shows the 12‐membered ring to be highly mobile at ambient probe temperature. At −89°C, these resonances are fully decoalesced. The value of ΔG‡ for the process that averages these peaks was found to be 10.1 kcal/mol at coalescence (−42.0°C).
Coordinating ability of the heterocycles 1,3‐dithia‐2‐arsa‐ and stiba‐cyclopentanes. Part III. Dithioacid and dithiocarbamate complexes containing a free functional group. Crystal structure of 2‐pyrrolidonedithiocarbamate of 1,3‐dithia‐arsa‐cyclopentane
Authors: Cea‐Olivares Raymundo , Toscano Rubén Alfredo , López Marcela , García Patricia
Published: January 2005

Three 1,1‐dithioacids containing an additional functional group, 2‐pyrrolidone‐1‐carbodithioic acid, 2‐hydroxycyclopentene‐1‐carbodithioic acid, and 2‐pyrrolidone‐1,3‐bis(carbodithioic) acid, were reacted with the Group 15 heterocycles 2‐chloro‐1,3‐dithia‐2‐arsa‐ and stiba‐cyclopentanes (CIMS2C2H4; M = As, Sb). The dithiocomplexes obtained were characterized by spectroscopic methods and elemental analyses. The X‐ray structure determination of the 2‐pyrrolidonedithiocarbamate of 1,3‐dithia‐arsacyclopentane shows a monodentate behavior of the dithiocarbamate entity and the absence of participation of the carbonyl oxygen in the coordination.
A[1,2,3]benzothiadiphospholo [3,2‐b]‐[1,2,3] benzothiadiphosphole as a further product from the reaction of aryl methyl thioethers with PCl3 and AlCl3
Authors: Baccolini Graziano , Mosticchio Carmine Antonio , Mezzina Elisabetta , Rizzoli Corrado , Sgarabotto Paolo
Published: January 2005

The title compound 2b was obtained as a minor product in the reaction between a thioanisole and PCl3/AlCl3. The crystal and molecular structure has been determined by single crystal X‐ray techniques. The compound crystallizes in the space group P 21/c, with α = 9.004(2), b = 13.416(3), c = 11.662(3) Å, and β = 93.1 (1)°. The molecule adoptes a “butterfly” arrangement.
1,4,7,8‐Triazaborabicyclooctanes—first examples of new boron heterocycles [1,2]
Authors: Tapia‐Benavides Antonio Rafael , Contreras Rosalinda
Published: January 2005

The first examples of 1,7,1,4,7,8‐dialkyltriazaborabicyclo[3.3.0]octanes 1–3 [R = isopropyl (1), R = 1‐phenylbenzyl (2), R = 1‐methylbenzyl (3)] are reported. The bulky substituents prevent dimerization and make the syntheses feasible. The structures and conformations of the new compounds were studied by NMR spectroscopy. A chiral bicycle 3 (R,R) was also prepared.
Phosphorylated indolizines
Authors: Tolmachev Andrew A. , Yurchenko Aleksander A. , Kozlov Ernest S. , Shulezhko Vasiliy A. , Pinchuk Aleksander M.
Published: January 2005

Preparative methods of synthesis of 1‐ and 3‐phosphino‐indolizines by interaction between 2‐substituted indolizines with phosphorus(III) halogenides in the presence of bases have been developed. It was found that originally this reaction results in the formation of 1‐phosphino‐indolizines which then undergo izomerization into 3‐phosphino isomers. One, two, or three indolizine substituents can be consecutively attached to the phosphorus atom. New methods of syntheses of 1,3‐diphosphino‐indolizines have been developed.
Structural evidence for Pπ‐Pπ conjugation in aminosubstituted phosphaalkynes
Authors: Chernega Alexander N. , Koidan Georg N. , Marchenko Anatoly P. , Korkin Anatoly A.
Published: January 2005

The molecular structure of 2,2,6,6‐tetramethylpiperidinophosphaalkyne was determined by the X‐ray structural method. The main geometrical parameters are as follows: PC 1.559(2), NC(sp) 1.316(2) Å, PCN 178.9(1)°, with an almost planar trigonal bond configuration for the N atom and the chair conformation of the piperidine ring. Structural evidence for the nitrogen lone pair conjugation with the π‐system of the triple bond was found to be different in phosphaalkynes PC‐NR2 and nitriles NCNR2. Quantum‐chemical ab initio calculations (HF/631G*) showed that this is caused by a different character of polarization of the PC and NC triple bonds.
Crystal structure and vibrational spectrum of copper mercury ortho‐thiophosphate CuHgPS4
Authors: Menzel Frank , Brockner Wolfgang , Carrillo‐Cabrera Wilder
Published: January 2005

The compound CuHgPS4 crystallizes in the orthorhombic system, space group Pna21 (No. 33), Z = 4, with lattice parameters a = 12.660(3), b = 7.3498(7), c = 6.0943(4) Å, and δcalc = 4.96 g/cm3. The title compound is stable in air and moisture and behaves as a semiconductor. The crystal structure consists of discrete tetrahedral PS43‐ anions joined together by Cu+ and Hg2+ cations. The arrangement of the sulfur atoms is approximately hexagonal close‐packed in which P, Cu, and Hg occupy tetrahedral sites. The PS4, HgS4, and CuS4 tetrahedra are slightly distorted with mean distances d(P‐S) = 2.055, d(Hg‐S) = 2.524, and d(CuS) = 2.320 Å, and 8% of the Hg atoms were found to be disordered, occupying interstitial tetrahedral sites. The title compound is isotypic to AgZnPS4 and can be considered to be a defect structure of Enargite (Cu3AsS4), which is a substitution derivative of the Wurtzite (ZnS) structure. The CuHgPS4 vibrational spectrum has been recorded. The internal modes experimentally observed are in accord with the factor group prediction. A tentative assignment of the vibrational frequencies is proposed.
Crystal and molecular structure and the absolute configuration of N‐phenyl‐N′‐(1‐phenylethyl)methanephosphonodiamidate
Authors: Wieczorek Michał W. , Błaszczyk Jarosław , Krzyżanowska Bożenna
Published: January 2005

The structural investigation of the product of the reaction of methanephosphonodichloridate with R(+)‐1‐phenylethylamine and aniline in the presence of triethylamine [3] was performed. The obtained compound C15H19N2OP (1) crystallizes in monoclinic system, space group P21 with a = 10.466(1) Å, b = 6.984(3) Å, c = 10.471(2) Å, β = 95.43(1)°, V = 762.0(9) Å3. Z = 2, and R = 0.037. The absolute configuration at the P and C8 atoms was determined by means of X‐ray crystallography as Rp and Rc8, respectively.
Reactions of triarylphosphines with organolithium reagents. Formation of biaryls
Authors: Uchida Yuzuru , Kawai Masaaki , Masauji Haruo , Oae Shigeru
Published: January 2005

Triarylphosphines bearing 2‐pyridyl or 2‐benzothiazyl groups react with organolithium reagents at −78°C in THF to afford both coupling products and ligand exchanged triarylphosphines. The ligand coupling and ligand exchange are considered to take place via an intermediate formed by the nucleophilic attack of a lithium reagent on the phosphorus atom.
Synthesis of Te‐alkyl carbamotelluroates from tellurium, carbon monoxide, amines, and alkyl halides
Authors: Inoue Toru , Mogami Toshiaki , Kambe Nobuaki , Ogawa Akiya , Sonoda Noboru
Published: January 2005

Lithium amides reacted with tellurium under atmospheric pressure of carbon monoxide to yield lithium carbamotelluroates which were trapped with alkyl halides to give Te‐alkyl carbamotelluroates in good yields. Results of control experiments suggested that lithium carbamotelluroates were formed by the reaction of tellurium with carbamoyllithiums generated in situ from lithium amides and carbon monoxide. It was revealed also that yields were improved when tellurium was preliminarily treated with lithium amides prior to the introduction of carbon monoxide into the reaction media.
The reaction of visnaginone, khillinone, and o‐hydroxy‐acetophenone with Lawesson's reagent
Authors: Shabana R. , Yakout E. M. , Atrees S. S.
Published: January 2005

Lawesson's reagent reacts with visnaginone (2a), khillinone (2b), and o‐hydroxyacetophenone (5) to give the 1,2‐oxaphosphinane derivatives 4a, 4b, and 6, respectively.
(Diazoalkyl)Phosphoranes from [4 + 1]‐cycloadditions of tetrahalo‐orthobenzoquinones to (diazoalkyl)phosphanes [1]
Authors: Nees Hans‐Joachim , Bergsträßer Uwe , Heydt Heinrich , Regitz Manfred
Published: January 2005

The (diazoalkyl)phosphanes 4a–e undergo [4 + 1]‐cycloaddition reactions with the tetrahalo‐orthobenzoquinones 5a,b to furnish the previously unknown (diazoalkyl)phosphoranes 6a–h. The structure of product 6h has been investigated by X‐ray crystallography.
Reactions of 2‐phospholene 1‐oxides with bromine in some media: Facile preparation of bromohydrin derivatives of 2‐phospholenes
Authors: Yamashita Mitsuji , Iida Akihito , Mizuno Hiroyuki , Miyamoto Yasushi , Morishita Toru , Sata Naoaki , Kiguchi Kenji , Yabui Akihiro , Oshikawa Tatsuo
Published: January 2005

Reactions of 1‐phenyl‐ and 1‐methoxy‐2‐phospholene 1‐oxides with bromine in aqueous organic solvents or in a protic medium, such as methanol, easily afforded the corresponding 2‐bromo‐3‐hydroxy‐ or 2‐bromo‐3‐methoxyphospholane 1‐oxide derivatives. The reaction mechanism was postulated based on the stereochemistry of the products.
1,5‐Dimethyl‐2,3,3,4‐Tetrachloro‐1,5‐Diaza‐2,4‐Diphosphorinan‐6‐One and some derivatives
Authors: Shevchenko I. V. , Krill J. , Schiebel H. M. , Schmutzler R.
Published: January 2005

A synthesis of C‐chlorinated analogues of 1,5‐diaza‐2,4‐diphosphorinan‐6‐ones is described. The P‐chlorophosphine 3, a key compound for all reported substitution reactions, reacts in an unusual way with N,N′‐dimethyl‐N,N′‐bis(trimethylsilyl)urea to give the unsymmetrical product 5, the formation of which is accounted for by a silatropy of the intermediate compound 4. Compound 5 is stable in solution but rearranges quantitatively into isomer 6 without solvent at room temperature. Compound 3, its fluoro derivative 9, and the alkoxy derivatives 10a–d exist as cis‐and trans‐isomers. Some stereochemical aspects, as well as the possibility of 1,2‐chlorotropy, are discussed.
Fluorescent tricyclic β‐azavinamidine–BF2 complexes
Authors: Sathyamoorthi Govindarao , Soong Mou‐Ling , Ross Timothy W. , Boyer Joseph H.
Published: January 2005

Boron trifluoride reacted with dipyrid‐2‐ylamine 6, its N‐methyl and 6,6′‐dimethyl derivatives 8 and 10, and 3,3′,5,5′‐tetraphenyl‐6‐azapyrromethene 13 to give fluorescent β‐azavinamidine (1,3,5‐triazapenta‐1,3‐diene) dyes: 10‐azapyridomethene–BF2 complex 5 (λf 422 nm, λlas 426 nm), its quaternary 10‐methyl tetrafluoroborate and 4,6‐dimethyl derivatives 9 (λf 362 nm) and 11 (λf 416 nm), and 1,3,5,7‐tetraphenyl‐8‐azapyrromethene–BF2 complex 17 (λf 696 nm). Treating 3,3′,4,4′‐tetraphenyl‐5,5′,6‐trimethylpyrromethene (prepared in situ from ethyl 3,4‐diphenyl‐5‐methylpyrrole‐2‐carboxylate in a reaction with acetyl chloride) with boron trifluoride gave 1,2,6,7‐tetraphenyl‐3,5,8‐trimethylpyrromethene–BF2 complex 21. Absorption for the vinamidine chromophore differed from that for the β‐azavinamidine chromophore by a hypsochromic shift of 86 nm in a comparison of pyridomethene–BF2 complex 3 with its 10‐aza derivative 5 and by a bathochromic shift of 105 nm in a comparison of the pyrromethene–BF2 complex 20 with the 8‐azapyrromethene–BF2 complex 17.
The reaction of allyldialkyltelluronium bromides with anilines
Authors: Xu Caiding , Lu Shoumao , Huang Xian
Published: January 2005

Allyldialkyltelluronium bromides were treated with aromatic amines in 1,2‐dichloroethane, readily giving allyl aryl amines in excellent yields.
Structure and reactions of benzo‐4‐diphenylphosphino‐2‐phenyl‐1,3,2‐dioxaborinane
Authors: Nikonov G. N. , Balueva A. S. , Karasik A. A. , Litvinov I. A. , Prokhorova S. R. , Kataeva O. N.
Published: January 2005

The crystal structure of 5,6‐benzo‐4‐diphenylphosphino‐2‐phenyl‐1,3,2‐dioxaborinane 1 indicates the occurrence of an interaction between the π‐systems of the 1,3,2‐dioxaborinane ring and the appropriate phenyl group of the diphenylphosphino group. Complexes of compound 1 with PtCl2, PdCl2, and Cul were synthesized. Compound 1 and its complexes are readily hydrolyzed in solution to give diphenylphosphine and its corresponding complexes (NMR).
Reactivity of a phosphoranyl radical generated by photoreaction of phenyl diphenylphosphinite with 10‐methylacridinium iodide. α‐Scission vs. single electron transfer
Authors: Yasui Shinro , Shioji Kosei , Ohno Atsuyoshi
Published: January 2005

Photoreaction of phenyl diphenylphosphinite (1b) with 10‐methylacridinium iodide (2) in aqueous acetonitrile under an argon atmosphere gives 10‐methylacridan, the reduction product from 2, in a quantitative yield and phenyl diphenylphosphinate, the oxidation product from 1b, in a low yield, as well as a large amount of diphenylphosphinic acid and a moderate amount of phenol. The product distribution observed here is interpreted well in terms of decomposition of a phosphoranyl intermediate through both α‐scission and single electron transfer (SET) pathways.
Study on the aromaticity and reactivity of chlorophosphinines
Authors: Nyulászi László , Keglevich György
Published: January 2005

Aromaticity of phosphinine derivatives, such as 2‐, 3‐, and 4‐chlorophosphinines and 4‐chloro‐3‐methyl‐and 3,5‐dimethylphosphinine, has been investigated by means of quantum‐chemical calculations and photoelectron spectroscopy. The position of the π‐bands in the photoelectron spectra of 4‐chloro‐3‐methyl‐ and 3,5‐dimethylphosphinine indicated that the aromaticity of these species is similar to that of the corresponding benzene derivatives.

The MP2/6‐31G* and the HF/3‐21G(*) geometries of the chlorophosphinines, together with the isodesmic reaction energies and Mulliken charge distributions, showed that the electronic system of phosphinine is not significantly perturbed by the chloro‐substitution.

3‐methyl‐4‐chlorophosphinine, similarly to 2‐chlorophosphinine, was inert toward nucleophiles even under forced conditions. This unreactivity can more likely be rationalized by kinetic considerations than by thermodynamic arguments (such as increased aromatic stabilization of the chlorophosphinines).
Reactions of fused dihydro‐1,2,4‐thiadiazoles with isocyanates and isothiocyanates to give 6aλ4‐thia‐1,3,4,6‐tetraazapentalene derivatives
Authors: Lai Long‐Li , Reid David H. , Nicol Robin H. , Rhodes Jane B.
Published: January 2005

3‐Methyl‐6,7‐dihydro‐5H‐1,2,4‐thiadiazolo[4,5‐a]pyrimidine 4a reacted with isocyanates and isothiocyanates with elimination of acetonitrile and concomitant addition of two molecules of the heterocumulene to give the 2,3‐disubstituted‐6,7‐dihydro‐5H‐2aλ4‐thia‐2, 3, 4a, 7a‐tetraazacyclopent[cd]indene‐1 (2H), 4(3H)‐diones 8a–8e and the corresponding dithiones 9a–9h, respectively. 3‐Methyl‐5, 10‐dihydrobenzo[e]‐1,2,4‐thiadiazolo[4,5‐a][1,3]diazepine 5a likewise reacted with isocyanates and isothiocyanates to give the 2,3‐disubstituted‐5,10‐dihydro‐2aλ4‐thia‐2,3, 4a, 10a‐tetraazapentaleno[3, 3a, 4‐gh]benzocyclopheptene‐1, 4‐diones 10a–10f and the corresponding dithiones 11a–11f. The base 4a reacted with phenyl isocyanate, methyl isothiocyanate, and phenyl isothiocyanate in toluene at room temperature to give the zwitterions 14a, 14b, and 14c, respectively, and the diazepine 5a reacted with phenyl isothiocyanate to give the zwitterion 17.
Prior ligand exchange, followed by ligand coupling in the reaction of 2‐pyridyl 2‐thienyl sulfoxide with 2‐thienyllithium or 2‐selenophenyllithium
Authors: Oae Shigeru , Inubushi Yoichi , Yoshihara Masakuni
Published: January 2005

2‐Pyridyl 2‐thienyl sulfoxide was found to react with variously substituted 2‐thienyllithiums and 2‐selenophenyllithium, exclusively affording 2‐(2‐pyridyl)thiophenes and 2‐(2‐pyridyl)‐selenophene and the disulfides derived from the substituted thiophenes and selenophene. Apparently, ligand exchange precedes ligand coupling. The coupling product always involved the pyridine nucleus, but no bithienyl‐type products were formed.
Selective side‐chain oxidation of peralkylated pyrrometheneBF2 complexes
Authors: Sathyamoorthi Govindarao , Wolford Lionel T. , Haag Anthony M. , Boyer Joseph H.
Published: January 2005

Treatment with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) oxidized 2,6‐diethyl‐1,3,5,7,8‐pentamethylpyrromethene–BF2 complex 1, 13,14‐trimethyl‐2, 3, 4, 5,9,10,11,12‐octahydroindomethene–BF2 complex 5, and 1,3,5,7,8‐pentamethyl‐1,2,3,5,6,7‐hexahydropyromethene–BF2 complex 8 to the weakly fluorescent 3‐formyl, 5‐oxo, and 8‐formyl derivatives 4, 6, and 9, respectively. The dye 1 was oxidized by lead tetraacetate to 1,7,8‐trimethyl‐2,6‐diethyl‐3,5‐diacetoxymethylpyrromethene–BF2 complex 12 [λf (ethanol) 538 nm, Φ 0.62, λlas (ethanol) 555–570 nm]. Catalytic reduction (Pd/C) converted the aldehyde 4 to 2,6‐diethyl‐3‐hydroxymethyl‐1,5,7,8‐tetramethylpyrromethene–BF2 complex 10 [λf (ethanol) 537 nm, Φ 0.70, λlas (ethanol) 547–575 nm].
The addition of carbonyl compounds to tetramesitylgermasilene and dimesitylgermylene
Authors: Baines Kim M. , Cooke Jeffrey A. , Vittal Jagadese J.
Published: January 2005

Hexamesitylsiladigermirane, 1, has been photolyzed/thermolyzed in the presence of three representative carbonyl compounds: acetone, pivalaldehyde, and benzaldehyde. In each case, a [2 + 2] adduct between the carbonyl compound and Mes2Ge = SiMes2 was formed regioselectively to give a 2,3‐silagermaoxetane. The 2,3‐silagermaoxetanes have been fully characterized by IR and NMR (1H, 13C, and 29Si) spectroscopy and mass spectrometry. In two cases, the structures have been confirmed by X‐ray crystallography: 4,4‐dimethyl‐2,2,3,3‐tetramesityl‐2,3‐silagermaoxetane, 2a; crystals are triclinic, space group P1 with Z = 2 in a unit cell of dimensions a = 12.318(3) Å, b = 12.436(2) Å, c = 11.884(2) Å, α = 100.13(1)°, β = 103.80(2)°, and γ = 89.97(2)°. The structure was solved by direct methods and refined by least squares on the basis of 2955 observed reflections to R1 and wR2 values of 0.0600 and 0.1363, respectively. The structure of 4‐tert‐butyl‐2,2,3,3‐tetramesityl‐2,3‐silagermaoxetane, 2b, was also determined; crystals are monoclinic, space group Cc with Z = 4 in a unit cell of dimensions a = 11.306(2) Å, b = 21.292(4) Å, c = 16.524(2) Å, and β = 106.83(1)°. The structure was determined by direct methods and refined by full‐matrix least squares on the basis of 1817 observed reflections to R1 and wR2 values of 0.0621 and 0.1681, respectively. An adduct between dimesitylgermylene and the carbonyl compound was also isolated in each reaction. The structure of the adduct appears to depend upon the steric bulk of the group attached to the carbonyl carbon.
Phenyllead(IV) diorganophosphinodithioates, PhnPb(S2PR2)4−n. Synthesis, spectroscopic characterization, and NMR study of the redistribution/decomposition of diphenyllead(IV) derivatives
Authors: Silvestru Cristian , Silvestru Anca , Haiduc Ionel , Ramírez Rubén Gaviño , Cea‐Olivares Raymundo
Published: January 2005

Tri‐ and diphenyllead(IV) diorganophosphinodithioates, PhnPb(S2PR2)4−n (n = 2 and 3; R = Me, Et, Ph) were prepared by reacting the corresponding organolead(IV) chloride with the sodium or ammonium salt of the phosphinodithioic acid. The title compounds were investigated by infrared, 1H and 31P NMR, and mass spectroscopy, and possible structures were proposed. The diphenyllead(IV) phosphinodithioates, Ph2Pb(S2PR2)2, undergo decomposition on standing or on moderate heating, the least stable being the ethyl derivative. The process was monitored by using 1H and 31P NMR spectroscopy, and a reaction pathway leading to Ph3PbS2PR2, Pb(S2PR2)2, and R2P(S)SPh was established.
Stereoselective formation of (2‐thenyl)‐substituted alkenes from 2‐chloromethylthiophene and lithium trialkylalkynylborates
Authors: Chen Yan , Deng Min‐Zhi
Published: January 2005

The reactions of 2‐chloromethylthiophene (an analog of a benzyl halide) with lithium trialkylalkynylborates gave, after protonation, E‐alkenes with a (2‐thenyl) substituent in good yields, and the reaction stereo‐selectivity was different from that of the reaction of benzyl bromide with an alkynylborate.
Sulfenylation of α‐phosphoryl sulfides. Chemical evidence for intermediate formation of α‐phosphoryl trithioorthoformate [1]
Authors: Bałczewski Piotr , Mikołajczyk Marian
Published: January 2005

1‐Lithio‐1‐(diethoxyphosphoryl)methyl methyl sulfide 1‐Li was reacted with diphenyl disulfide in a tetrahydrofuran solution to give predominantly diethyl methylthio(phenylthio)methylphosphonate 2 accompanied by a small amount of diethyl bis‐(phenylthio)methyl phosphonate 3. The latter was the main product when the reaction was performed in the absence of the solvent. The formation of 3 was explained through the desulfenylation of the transiently formed diethyl methylthiobis(phenylthio)methylphosphonate 4 with lithium benzenethiolate and confirmed by 31P NMR measurements at low temperature.
Synthesis and properties of novel amino acid linked phosphoryl nitrogen mustard derivatives
Authors: Chen Ru‐Yu , Wang Hui‐Lin , Zhou Jia
Published: January 2005

In order to look for novel antitumor drugs and virucides with high activity and low toxicity, a series of amino acid linked phosphoryl nitrogen mustard derivatives have been synthesized. The structures of all compounds prepared were confirmed by 1H NMR, 31P NMR, IR, MS spectroscopy, and elemental analyses. In the case of dl‐α‐amino acid derivatives, the presence of multiple chiral centers in the target products leads to the generation of diastereoisomers, which can be detected by spectroscopic and analytical (TLC) methods. Preliminary bioassays indicate that some of compounds 5 have high inhibitory activities against some tumor cells and tobacco mosaic virus (TMV). In addition, some of them display certain herbicidal activities and significant fungicidal activities against wheat leaf rust.
Geometry and conformation of crystalline forms of β‐naphthoxy‐substituted 2‐thio‐1,3,2‐oxathiaphospholanes and 2‐thio‐1,3,2‐dithiaphospholanes
Authors: Błaszczyk Jarosław , Wieczorek Michał W. , Okruszek Andrzej , Olesiak Magdalena , Karwowski Bolesław
Published: January 2005

Three compounds (1, 2, and 3) containing 1,3,2‐oxathiaphospholane and 1,3,2‐dithiaphospholane rings were subjected to structural studies by the X‐ray method. Compounds 1 and 3 attain a half‐chair conformation, whereas, for compound 2, an envelope conformation of the five‐membered heterocyclic ring was found in the solid state. For all three compounds, a site occupation of some structural elements in a unit cell was observed.
Synthesis and assignment of absolute configuration of enantiomeric dicyclohexylammonium 2‐oxo‐2‐thioxo‐1,3,2‐oxathiaphospholanes
Authors: Krzyżanowska Bożenna , Stec Wojciech J. , Wieczorek Michał W. , Błaszczyk Jarosław
Published: January 2005

The title compound 2 has been synthesized and its structure has been determined by X‐ray analysis. The following crystal data were found: monoclinic, P21, a = 9.936(4), b = 18.009(3), c = 10.418(3) Å, and β = 107.22(3)°. Two molecules of the compound (two oxathiaphospholane anions and two dicyclohexylammonium cations) are present in the independent part of the unit cell. The absolute configuration at the phosphorus atom is established as Rp. The ionic character of 2 is discussed. In the crystal lattice of 2, a hydrogen‐bonding system occurs.
Low‐temperature 1H, 13C, 77Se, and 125Te NMR studies on the apical‐apical ligand exchange via the hypervalent tellurium and selenium ate complexes [10‐M‐3(C3); M = Se, Te] in the reactions of diaryl tellurides and selenides with aryllithium reagents
Authors: Masutomi Yutaka , Furukawa Naomichi , Erata Tomoki
Published: January 2005

Pentafluorophenyl phenyl telluride (1) and 3,5‐dichloro‐2,4,6‐trifluorophenyl phenyl telluride (2) react with pentafluorophenyllithium or 3,5‐dichloro‐2,4,6‐trifluorophenyllithium in THF at low temperatures to form the corresponding tellurium ate complexes (A) and (B) as sole intermediates in the ligand exchange on the hypervalent tellurium atom. The corresponding selenides (3) and (4) also react with identical aryllithium reagents in THF to form the discrete intermediates, selenium ate complexes (C) and (D), in the exchange reactions. In these ligand exchange reactions of tellurides and selenides, electron‐withdrawing ligands occupy the apical positions and the exchange takes place between these apical‐oriented groups. The low‐temperature 1H, 13C, 77Se, and 125Te NMR spectroscopic techniques are effective methods for detection of unstable tellurium and selenium ate complexes.
Synthesis and reactions of diphosphenes carrying bulky aryl and phenoxy groups
Authors: An De‐Lie , Toyota Kozo , Yasunami Masafumi , Yoshifuji Masaaki
Published: January 2005

Unsymmetrical diphosphenes carrying bulky aryl and phenoxy groups were prepared by the reaction of lithium 2,4,6‐tri‐t‐butylphenylphosphide with the corresponding phenyl phosphorodichloridites, followed by the dehydrochlorination reaction with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene. The diphosphenes were isolated as stable compounds. The reactions of these diphosphenes with elemental sulfur or selenium afforded the corresponding thiadiphosphiranes or selenadiphosphiranes, respectively. The diphosphenes also reacted with dichlorocarbene to give dichlorodiphosphiranes.
Formation and X‐ray structure of a silver iodide based polymeric complex (Ag5l6)n(Ph3PCH2l)n
Authors: Jin Xianglin , Tang Kaluo , Liu Weidong , Tang Youqi
Published: January 2005

Compounds [(Ph3P)2AgS2CSR (R = But, TIPT(2,4,6‐triisopropylthiophenolato))], formed by inserting CS2 into the Ag–S bond in AgSR in the presence of PPh3, react with CH2I2 to give pale yellow crystals of (Ag5I6)n(Ph3PCH2I)n, which consist of the polymeric anion (Ag5I6)n− and the cation (Ph3PCH2)+. The polyanion (Ag5I6)n− is composed of alternate I5‐pentagons and Ag5‐pentagons that are connected by Ag–I bonds along the C axis to form a layered “pagoda” structure, in which there exists an unusual stereochemistry of iodine. Crystal data: monoclinic, space group P21/c, a = 15.004(12) Å, b = 27.19(2) Å, c = 7.898 Å, β = 97.18(5)°, V = 3205(4) Å3, Z = 4, R = 0.0673 for 2726 observed reflections.
Synthesis of C‐nucleosides via coupling of ribosyl fluoride with typical aromatic heterocycles bearing a TMS group
Authors: Yokoyama Masataka , Nomura Mitsuru , Tanabe Takeshi , Togo Hideo
Published: January 2005

The direct coupling reaction of D‐ribosyl fluoride with typical π‐excessive aromatic heterocycles such as furan, thiophene, pyrrole, benzofuran, benzothiophene, and indole and their trimethylsilyl derivatives was performed in the presence of boron trifluoride to afford the corresponding C‐nucleosides in moderate to good yields.
Generation of metal phosphinites by the reaction of Se‐alkyl phosphinoselenoates with organometallics and its application to the synthesis of optically active organophosphorus compounds
Authors: Kawashima Takayuki , Iwanaga Hiroki , Okazaki Renji
Published: January 2005

Reaction of Se‐Alkyl phosphinoselenoates with organometallics resulted in a selective attack on the selenium atom. Sequential treatment of optically active Se‐benzyl t‐butylphenylphosphinoselenoate with PhLi and then with electrophiles, such as alkyl halides, an α,β‐unsaturated ester, and chalcogen atoms gave optically active phosphorus compounds in 5–91% yields and in high optical yields, with retention of configuration at the phosphorus atom, along with a quantitative yield of benzyl phenyl selenide.