Showing papers in "Phosphorus Sulfur and Silicon and The Related Elements in 1995"
TL;DR: The hexameric n-butyloxotin benzoate, [n-BuSn(O)O2CC6H4NO2.2]6] and the dimeric methyloxotin cyclohexanoate, this article, were prepared by condensing the stannoic acid with the respective carboxylic acid.
Abstract: The hexameric n-butyloxotin benzoate, [n-BuSn(O)O2CC6H4NO2.2]6.3C6H6, 1, and the dimeric methyloxotin cyclohexanoate, [(MeSn(O)O2CC6H11)2MeSn(O2CC6H11)3]2, 4, were prepared by condensing the stannoic acid with the respective carboxylic acid. Reaction of n-butyltin. trichloride with the silver salt of the respective carboxylic acid gave the dimeric n-butyloxotin carboxylate compositions, [(n-BuSn(O)O2CR)2-n-BuSn(O2CR)3]2, 2 (R = Ph) and 3 (R = Me). These represent new substances and, as found by X-ray analysis, form a new structural class of organotin compounds for 2-4 having “unfolded drum” or “ladder” structures. The hexamer composition 1 exists in “drum” form. 119Sn NMR data show that the drum and ladder structures interconvert reversibly. 1 crystallizes in the rhombohedral/space group R3 with a H = 15.283 (4) A, cH, = 34.683 (9) A, and Z = 3. 2 crystallizes in the triclinic space group P1 with a = 13.657 (6) A, b = 14.104 (2) A, c = 14.559 (4) A, a = 99.14 (2)°, β = 111.73 (3)°, γ = 101.57 (3)...
112 citations
TL;DR: Although oligomeric organotin oxycarboxylates based on the composition [RSn(O)O2CR′] n have been known for some time, 2 no indications of their possible structural features are available as mentioned in this paper.
Abstract: Although oligomeric organotin oxycarboxylates based on the composition [RSn(O)O2CR′] n have been known for some time, 2 no indications of their possible structural features are available. As early as 1921 some members of this class were reported3 to be hexameric, e.g., [CH3Sn(O)O2CR]6.
70 citations
TL;DR: Arsenic(III) oxide and arsenous acid in water or aqueous ethanolic solutions react, at room temperature, with a variety of lipophilic and hydrophilic thiols giving quantitatively triaryl and trialkyl trithioarsenites, RSSR as discussed by the authors.
Abstract: Arsenic(III) oxide and arsenous acid in water or aqueous ethanolic solutions react, at room temperature, with a variety of lipophilic and hydrophilic thiols giving quantitatively triaryl and trialkyl trithioarsenites, (ArS)3As and (RS)3As. Aqueous solutions of arsenic acid react with certain thiols giving quantitatively mixtures of trithioarsenites and disulfides, RSSR. These reactions may help towards the elucidation of the biochemistry of arsenous and arsenic acids.
48 citations
TL;DR: In this paper, the reversibility of hydroxyphosphonate synthesis in the Kabachnik-Fields synthesis was studied and it was found that in all studies cases which included aliphatic and aromatic aldehydes or ketones, the hydroxy phosphonates decompose to the starting ketone and dialkyl phosphite in the presence of aliphatically amines as determined by 1H-, 13C-, 31P-NMR.
Abstract: The reversibility of hydroxyphosphonate synthesis in the Kabachnik-Fields synthesis was studied. It was found that in all studies cases which included aliphatic and aromatic aldehydes or ketones the hydroxyphosphonates decompose to the starting ketone and dialkyl phosphite in the presence of aliphatic amines as determined by 1H-, 13C-, 31P-NMR.
35 citations
TL;DR: The styrlpyridinethione 1a-c reacted with several halogenated compounds; ω-bromoacetophenone, methyl chloroacetate, α-chloroacetylacetone and ethyl-α-cloacetoacetates as discussed by the authors.
Abstract: The styrlpyridinethione 1a–c reacted with several halogenated compounds; ω-bromoacetophenone, methyl chloroacetate, α-chloroacetylacetone and ethyl-α-chloroacetoacetate to give the corresponding thieno[2,3-b]pyridines 3a–c, 11a–c and the thiazolo[3,2-α]pyridines 14a–c.
32 citations
TL;DR: In this paper, α-aminophosphonic esters and acids derived from furan, thiophene and pyrazole were prepared in high yield, in the reactions of benzylamine, benzhydrylaraine or benzyl carbamate with heterocyclic aldehydes and diethyl or diphenyl phosphonates.
Abstract: New α-aminophosphonic esters and acids derived from furan, thiophene and pyrazole were prepared in high yield, in the reactions of benzylamine, benzhydrylaraine or benzyl carbamate with heterocyclic aldehydes and diethyl or diphenyl phosphonates. The protecting groups at amine (benzyl or benzhydryl) were removed by hydrogenolysis or hydrolysis, respectively. The N-benzyloxycarbonyl (Z-group) was removed by treatment with 45% HBr in acetic acid.
29 citations
TL;DR: In this article, it was shown that pentacoordinated compounds form a continuous series of structures, similar to phosphoranes, between the trigonal bipyramid and square or rectangular pyramid along the Berry pseudorotational pathway.
Abstract: Hexamethylenediammonium bis[bis(1,2-ethylenediolato)phenylsilicate(IV)], [H3N(CH2,)6NH3]05-[(C2H4O2)2SiPh], 4, and tetraethylammonium bis(3,4,5,6-tetrachloro-1,2-benzenediolato)phenylsilicate(IV), [Et4N][(C6Cl4O2)2SiPh], 5, were synthesized and their X-ray structures established 4 has a structure displaced 72% from a trigonal bipyramid (TBP) to a rectangular pyramid (RP) 5 is nearly a rectangular pyramid (RP) being 90% so displaced A quantitative assessment of structural distortion for 4 and 5 and related anionic silicates shows that these pentacoordinated compounds form a continuous series of structures, similar to phosphoranes, between the trigonal bipyramid and square or rectangular pyramid along the Berry pseudorotational pathway It is shown that the idealized RP geometry is approached when two five-membered unsaturated rings are present with like ligands in any one ring attached directly to silicon The existence of this low-energy coordinate indicates the presence of nonrigid character
28 citations
TL;DR: Di-1-adamantylchlorophosphine 3 was obtained by a three-step sequence from commercially available adamantane as discussed by the authors, and it reacts readily with water to give di-1adamantsylphosphine oxide 4.
Abstract: Di-1-adamantylchlorophosphine 3 is obtained by a three step sequence from commercially available adamantane. Despite the bulky 1-adamantyl groups at the phosphorus atom, it reacts readily with water to give di-1-adamantylphosphine oxide 4.
28 citations
TL;DR: Pyridinium bis(2,3-naphthalenediolato)phenylsilicate(IV), [(C10H6O2)2SiPh][C5H6N], 11, pyridine bis(1,2-benzenediolatos)-1 naphthylsilicates(IV) (2-Cl, 0.85; 5-Cl 0.15), and [(C6H4O2]2SiC 6H4Cl][C 5H6Ns], 13, were synthesized and their
Abstract: The new five-coordinated silicon compounds, pyridinium bis(2,3-naphthalenediolato)phenylsilicate(IV), [(C10H6O2)2SiPh][C5H6N], 11, pyridinium bis(1,2-benzenediolato)-1-naphthylsilicate(IV), [(C6H4O2)2SiC10H7][C5H6N], 12, and pyridinium bis(1,2-benzenediolato)(2- and 4-chlorophenyl)silicate(IV) (2-Cl, 0.85; 5-Cl, 0.15), [(C6H4O2)2SiC6H4Cl][C5H6N], 13, were synthesized and their X-ray structures determined. The structure of 11 is nearly an ideal rectangular pyramid (RP) and 12 is displaced about halfway between the RP and trigonal bipyramid (TBP), while 13 is closer to a TBP. A quantitative assessment of these and related pentacoordinated cyclic anionic silicate structures reveals a continuous change in ring Si[sbnd]O bond lengths that vary from 1.78 (axial) and 1.68 A (equatorial) for the idealized TBP to 1.73 A (basal) for the RP. The results for these compounds, all of which follow the Berry pseudorotational coordinate, suggest a structural nonrigidity at least as great as found for phosphoranes...
24 citations
TL;DR: A series of 1-hydrazino- and 2-hexane-alkyl (aryl) phosphonic acids and their derivatives were prepared from the corresponding hydrazono compounds by treatment with sodium cyanoborohydride or with the borane-tetrahydrofuran complex, respectively.
Abstract: A series of 1-hydrazino- and 2-hydrazino-alkyl (aryl) phosphonic acids and their derivatives were prepared from the corresponding hydrazono compounds by treatment with sodium cyanoborohydride or with the borane-tetrahydrofuran complex, respectively.
24 citations
TL;DR: In this paper, the synthesis, properties and NMR spectra of organobismuthanes RBi[S2P(OR′)2]2 (R = Ph, pTol; R′ = Me, Et, iPr, Ph) are discussed.
Abstract: Synthesis, properties and NMR spectra of organobismuthanes RBi[S2P(OR′)2]2 (R = Me, Ph, pTol; R′ = Me, Et, iPr, Ph) and R2BiS2P(OR′)2 (R = Ph, pTol; R′ = Me, Et, iPr, Ph) are discussed. Tris(O,O′-diorganodithiophosphato)bismuthanes Bi[S2P(OR)2]3 (R = Me, Et, iPr, Ph) are generated from R3Bi (R = Me, Et) and the corresponding phosphorus compound HS2P(OR)2 (R = Me, Et, iPr, Ph) in yields of about 50%. Crystals of Bi[S2P(OMe)2]3 are monoclinic (space group P21/c) with the following cell parameters: a = 1509.6(6), b = 786.5(4), c = 1909.5(1) pm, β = 109.907(6)°, V = 2133.21(5) ∗ 106 pm3, Z = 4. The compound appears to be dimeric in the solid state resulting in the formation of an eight membered ring system. Es werden Synthese, Eigenschaften und NMR-Spektren von Organobismutanen des Typs RBi[S2P(OR′)2]2 (R = Me, Ph, pTol; R′ = Me, Et, iPr, Ph) und R2BiS2P(OR′)2 (R = Ph, pTol; R′ = Me, Et, iPr, Ph) diskutiert. Tris(O,O′-diorganodithiophosphato)bismutane der Zusammensetzung Bi[S2P(OR)2:]3(R = Me, Et, iP...
TL;DR: In this article, unsymmetrical diphosphazanes of the type X2PN(Pr1)PYY′ were prepared and converted into their mono-and di-oxides or sulfides.
Abstract: New unsymmetrical diphosphazanes of the type X2PN(Pr1)PYY′ {X = Ph, YY′ = O2C12H8 (1a), O2C20H12 (1h); X = Ph, Y = Ph, Y′ = OC6H4Me-4 (1c), OC6H4Br4(1d), OC6H3Me2-3,5 (1e), N2C2H3 (1f), N2C3HMe2-3,5 (1g), OC5H4N-2 (1h)} are prepared and converted into their mono- and di-oxides or sulfides. These can function as heterofunctional ligands through P, S, N or O donor sites. These compounds have been characterized by NMR spectroscopic studies. Variable temperature 31P{1H} NMR measurements on some of these compounds reveal the presence of different types of conformers in solution. Single crystal X-ray diffraction studies have been carried out for Ph2P(S)N(Pr1)PPh(N2C3HMe2-3,5) (2g) and Ph2P(O)N(Pr1)P(O)Ph(OC5H4N-2) (5b).
TL;DR: In this article, the synthesis of phenylene-bis-aminomethanomethanephosphonic and phosphonous acids was studied, and the title compounds were prepared in the reaction of the phenylene di-imine with dialkyl phosphite or hypophosphorous acid.
Abstract: The studies on the synthesis of phenylene-bis-aminomethanephosphonic and phosphonous acids are reported. The title compounds were prepared in the reaction of the phenylene di-imine with dialkyl phosphite or hypophosphorous acid. Addition of the second phosphorus nucleophile to the bisimine appears to be stereospecific.
TL;DR: In this article, a structural study using X-ray cristallography of the complexes of the title has been done and the results showed that the size of the cation strongly modifies the structure of the complex.
Abstract: Structural study using X-ray cristallography of the complexes of the title has been done. Alendronate is already known to be a very good chelator of divalent cations and supramolecular species obtained with alendronate and these cations are very stable and make them able to be used in biological systems. Our study points out that the size of the cation strongly modifies the structure of the complex. With Cu(II) and Zn(II) which are two cations with proximate ionic radii one cation is put in the centre of the coordination system and structures are isomorphous. On the other hand, with Cd(II), a binuclear complex is obtained. Results are discussed on the basis of these structures.
TL;DR: Amino-2-arylethylphosphonic acids have been shown to have a strong inhibition of anthocyanin synthesis in vitro as discussed by the authors, but not in vivo.
Abstract: 2-Amino-2-arylethylphosphonic acids, 6a to 6q have been prepared from the corresponding 2-acetoxyimino-or 2-methoxyimino-2-aryl-ethylphosphonates, 3 or 4, by hydrogenation using Raney-Ni as a catalyst, followed by hydrolysis with HCl. 3 and 4 were obtained from the corresponding aryl-bromomethyl-ketoxime-O-acetates, 1, or aryl-bromomethyl-O-methylketoximes, 2, by an Arbuzov reaction with triethylphosphite. Several of the 2-amino-2-arylethylphosphonic acids 6 show activity against Botrytis cinerea and Cercospora. Among the more active compounds were 6a, 6b, 6g and 6k, whereby 6b and 6k gave full protection against Botrytis cinerea (on apple) down to 60 ppm. The same compounds show also a weak inhibition of anthocyanin synthesis in vivo.
TL;DR: In this article, a hemilabile rhodium complex with phosphonate-phosphane ligands (RO)2P(O)(CH2nPPh2 1a-c (n = 1-3) has been synthesized and characterised.
Abstract: New hemilabile rhodium complexes with phosphonate-phosphane ligands (RO)2P(O)(CH2)nPPh2 1a-c (n = 1-3) have been synthesized and characterised. Effective methods for the preparation of the ligands were developed and the characterisation was carried out with IR and NMR spectroscopy. Additionally, 1b and 1c were converted into the corresponding phosphonate-phosphanoxyds 4b, c, and phosphonate-phosphonium bromides 5b, c. Both, open-chain (2a-c) and chelate (3a-c) rhodium complexes were easily accessible from 1a-c. The hemilabile behaviour of the rhodium complexes 2 and 3 was demonstrated by their smooth conversion into each other. The structure of the phosphonate-phosphane ligands 1a-c significantly affected the catalytic properties of 2a-c in methanol carbonylation.
TL;DR: In this article, four gem-bisphosphonic doxorubicin conjugates are prepared by coupling the amino function of dox-orubaicin with the activated carboxylic functions of 3, 3,3-bis(diethylphosphono)propanoic acid 2, 4,4-bis (diethlyphosphonono)butanoic amino acid 3, and (R + S)-N-(9-fluorenylmethyloxycarbonyl)-2-amino-4, 4-bis
Abstract: Four gem-bisphosphonic doxorubicin conjugates are prepared by coupling the amino function of dox-orubicin with the activated carboxylic functions of 3,3-bis(diethylphosphono)propanoic acid 2, 4,4-bis(diethylphosphono)butanoic acid 3, and (R + S)-N-(9-fluorenylmethyloxycarbonyl)-2-amino-4,4-bis(diethylphosphono)butanoic acid 6 The last compound provides two epimers which are separated by chromatography Sodium salts are obtained These original products participate in a biological study about a delivery-targeting concept of antineoplastic agents in bone cancer therapy, with the assistance of gem-bisphosphonic building blocks
TL;DR: In this article, the Kabachnik-Fields and Moedritzer-lrani reactions are studied in the case of 1-2 diamino trans cyclohexane dl as aminated component.
Abstract: The Kabachnik-Fields and Moedritzer-lrani reactions are studied in the case of 1-2 diamino trans cyclohexane dl as aminated component. The new bicyclic bis phosphonates 1, 1′, la have been obtained in the first case and the tetra phosphonic acid 2′ in the second one. The methylene bridge between the two nitrogen atoms in 1 and la is a protecting group that is stable in basic medium and readily removed at 20°C in acidic conditions. The 1H, 31C and 31P spectra are reported for all new compounds.
TL;DR: In this paper, selective desulfenylation of α-sulfur-and α-seleno-substituted phosphonates under free radical conditions is described.
Abstract: Selective desulfenylation and deselenylation of α-sulfur- and α-seleno-substituted phosphonates under free radical conditions are described. Chemoselectivity and scope of the title reactions were studied using phosphonates additionally functionalized in the α-position by alkyl, phenyl, ethoxy, chloro, car-bonyl and sulfenyl groups. It was found that reduction of a halogen tolerates the presence of the sulfenyl group and the latter could be reduced in the presence of the sulfinyl and sulfonyl moieties. Moreover, one sulfenyl group was selectively removed from α-phosphoryl dithioacetals and the phenylsulfenyl group was reduced preferentially in the presence of the methylsulfenyl one.
TL;DR: By coupling in pairs in all possible ways the eight hybridization types of a neutral phosphorus atom, 37 modes of formation of a phosphorus-phosphorus bond are obtained as discussed by the authors, and two other possibilities were also envisaged.
Abstract: By coupling in pairs in all possible ways the eight hybridization types of a neutral phosphorus atom, 37 modes of formation of a phosphorus—phosphorus bond are obtained. Some experimental results illustrate these modes and structural possibilities which offer the best hope of future success are predicted. Two other possibilities were also envisaged. The one in which one phosphorus atom is neutral, the other being cationic comprises 39 different P—P+ modes of hybridization. Coupling the eight neutral hybridization types of a phosphorus atom with the 13 possible anionic ones leads to 94 modes of formation of a P—P+ bond.
TL;DR: In this article, the synthesis of new benzimidazo-2-ylthiophenes, and benzo[g]imidazolylacetonitrile (BIL) pyridines utilizing 2-benz-imidazylacetitrile as starting component is reported.
Abstract: The synthesis of new benzimidazo-2-ylthiophenes, and benzo[g]imidazo[1,2-a]pyridines utilizing 2-benz-imidazolylacetonitrile (1) as starting component is reported.
TL;DR: In this article, the authors considered possible reaction mechanisms and structural assignments based upon analytical, chemical and spectroscopic (IR, 1H NMR, 31P NMR and MS) results.
Abstract: 5-Methylisatin ( 1b) reacts with TAP ( 4a–c) and/or DAP ( 3a-c) to give the respective dialkyl α-hydroxyphosphonates (8a-c). Isatin-monoxime ( 5a) and 5-methyl isatin-monoxime ( 5b) react with alkyl phosphites to give dialkyl 2-oxo-indolyl phosphorates ( 8a–c, 12a–f, 15a–c) as major products. The carbonyl-group at position – 3 in 1b is deoxygenated by triphenylphosphine to give a new phosphorus ylide ( 17 ) and by methylenetriphenylphosphoranes (Wittig-reagents, 7a-c) to afford the respective 3- substituted methylenes ( 19a-c) in good yields. Possible reaction mechanisms were considered and structural assignments were based upon analytical, chemical and spectroscopic (IR, 1H NMR, 31P NMR and MS) results.
TL;DR: In this paper, trialkyl phosphites or diethyl phosphite with trifluoroacetirnidoyl chlorides were obtained by the reaction of trialky phosphite or diet-hyl-phite with triacetyl-nidyl chlorides followed by subsequent reduc...
Abstract: 1-(N-substituted amino)-2,2,2-trifluoroethylphosphonates were obtained by the reaction of trialkyl phosphites or diethyl phosphites with trifluoroacetirnidoyl chlorides followed by subsequent reduc...
TL;DR: Lawesson's reagent (LR) reacts with 1,2-phenylenediamine derivatives (2a-c) to give 1,3-dihydro-1,3, 2-diazaphosphole-2-sulfide (3a-e) as discussed by the authors.
Abstract: Lawesson's reagent (LR) reacts with 1,2-phenylenediamine derivatives (2a-c) to give 1,3-dihydro-1,3,2-diazaphosphole-2-sulfide (3a-e). Also it reacts with 2-aminophenol (4) and 2-amino-2-methyl-1-pro-panol (6) to give 1,3,2-oxazaphospholes 5, 7 respectively.
TL;DR: The reaction between carboxylic acids, bromocyane and triphenylphosphine (Ph3PBrCN), affords under similar conditions acyl bromides as discussed by the authors.
Abstract: Acyl halides, i.e., acyl bromides and acyl chlorides can be generated in high yields under mild conditions from the corresponding carboxylic acid in the presence of equivalent amounts of NBS/NCS and tri-phenylphosphine. The reaction between carboxylic acids, bromocyane and triphenylphosphine (Ph3PBrCN), affords under similar conditions acyl bromides. Bromocyanotriphenylphosphorane reacts also smoothly with epoxides, e.g., phenyloxirane. It appears, however, that the expected bromocyanides are not obtainable by this reaction, vicinal dibromides being formed instead.
TL;DR: The charge transfer (CT) complexes of Schiff bases derived from S-methyldithiocarbazate and tetracyanoethylene (TCNE) have been studied spectrophotometrically as discussed by the authors.
Abstract: The charge-transfer (CT) complexes of Schiff bases 2a-e derived from S-methyldithiocarbazate and tetracyanoethylene (TCNE) have been studied spectrophotometrically. S-methyldithiocarbazate 1 reacted with TCNE to yield 3-amino-4,5-dicyano-6-S-methyl-pyridazine 12 and 4,5-diamino-1,8-di-S-meth-ylpyridazino[4,5-d]pyridazine 13 via CT-complexes, whereas 2a-e reacted with TCNE to afford 3-aryl-4-amino-5-cyano-6-S-methylpyridazines 22 and 3-aryl-5-S-methyl-1,2,4-thiadizaoles 16.
TL;DR: In this article, new derivatives and analogues of N-phosphonoacetyl-L-aspartate (PALA) were synthesized starting from the aspartic acid and evaluated for the enzymatic inhibition of the ATCase.
Abstract: New derivatives and analogues of N-phosphonoacetyl-L-aspartate (PALA) were synthesized starting from the aspartic acid and evaluated for the enzymatic inhibition of the ATCase. De nouveaux derives et analogues du N-phosphonoacetyl-L-aspartate (PALA), resultant de l'amen-agement fonctionnel selectif de e1eacide aspartique ont ete synthetises et leur activite inhibitrice de 1′ATCase a ete mesuree.
TL;DR: In the presence of phosphoryl group, N-phosphoamino acids become more reactive and self-catalyzed to form peptides by coupling with amino acids or their esters at low temperature in different solvents, even water.
Abstract: In the presence of phosphoryl group, N-phosphoamino acids become more reactive and self-catalyzed to form peptides by coupling with amino acids or their esters at low temperature in different solvents, even water. It might he important for the prebiotic synthesis of a protein.
TL;DR: In this paper, the TV-protected derivatives with O-benzyl-N,N′-dicyclohexylo-isoureas are described. And the differences in the reactions of aminoalkylphosphonic and amino-phosphonous acids are pointed out.
Abstract: Protection of the amino group of aminophosphonic and aminophosphonous acids with benzyl chloro-formate followed by esterification of the TV-protected derivatives with O-benzyl-N,N′-dicyclohexylo-isoureas is described. The esterification of aminobenzylphosphonic and aminobenzylphosphonous acids was studied in some details in order to discuss the scope and limitation of this procedure. The differences in the reactions of aminoalkylphosphonic and aminoalkylphosphonous acids are pointed out.
TL;DR: In this article, the first representative of oligoarylenephosphocyclanes was obtained and the structure of these compounds was confirmed by an X-ray structure analysis, which led to cis-isomers.
Abstract: Based on phenylphosphonous acid tetraethyldiamide and 2,2-di(p-oxyphenyl)propane diarylenecyclo-phenylphosphonite is synthesized. Its oxidation and sulfurization is investigated. It is shown that these reactions are stereospecific and lead to cis-isomers. The compounds obtained are the first representatives of oligoarylenephosphocyclanes. The structure of these compounds is confirmed by an X-ray structure analysis.