Structural studies of seven homoisoflavonoids, six thiohomoisoflavonoids, and four structurally related compounds

¹H and ¹³C NMR chemical shifts have been determined and assigned based on PFG ¹H, ¹³C HMQC, and HMBC experiments for 3-(4′-X-benzyl)-4-chromenones (Ia, X = CN and Ib, X = NO₂), 3-(4′-X-benzyl)-4-thiochromenones (IIa, X = Cl and IIb, X = Br), (E)-3-(4′-X-benzylidene)-4-chromanones (IIIa–IIIe, X = OCH₃, CH₃, Cl, N(CH₃)₂, Br), (Z)-3-(4′-X-benzylidene)4-thiochromanones (IVa–IVd, X = Cl, Br, F, OCH₃), 2-benzyl-1,2,3,4-tetrahydro-1-naphthol (V), 2-benzyl- and (E)-2-benzylidene-1-tetralones (VI and VII), and (E)-2-benzylidene-1-benzosuberol (VIII). The crystal structures have been determined for the following seven compounds: derivatives of 4-chromanones (IIIa–IIId), 1-tetrahydronaphtol (V), and 1-tetralones (VI and VII). The molecular features and intermolecular interactions in crystal state have been discussed.     

Theoretical refinements of theendo and theexo structures of tetraborane(8) carbonyl

The molecular structures of theendo (1a) andexo (1b) isomers of B₄H₈CO have been optimized at the ab initio MP2(Full)/6-31G^* level of theory. The agreement of the computed geometrical parameters with the recently published electron-diffraction (GED) data is very good, even though a number of geometrical constraints were applied in the experimental determination. The IGLO (individual gauge for localized orbitals)¹¹B NMR chemical shifts, calculated at the II//MP2/6-31G^* level, are also in accord with experiment. The formation of1a and1b by association of B₄H₈ and CO is computed to be exothermic by 22.8 and 22.2 kcal/mol, respectively, at the MP2(Full)/6-31G^*//MP2(Full)/6-31G^* + ZPE(6-31G^*) level of theory. The Lewis acid strength of B₄H₈ toward CO is comparable to that of BH₃.     

Synthesis and characterization of novel 2-(1-benzyl-3-[4-fluorophenyl]-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-one derivatives

Novel 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e were synthesized via Vilsmeier-Haack reaction of the appropriate 1-benzyl-2-(1-(4-fluorophenyl)ethylidene)hydrazines, derived from 4-fluoroacetophenone 1 with substituted 2-benzylhydrazines 2a to 2e . The base catalyzed condensation of 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e with 1-(4-fluoro-2-hydroxyphenyl)ethanone 4 gave (E)-3-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-1-(4-fluoro-2-hydroxyphenyl)prop-2-en-1-ones 5a to 5e . On cyclization with dimethyl sulfoxide (DMSO)/I₂, compounds 5a to 5e gave 2-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-ones 6a to 6e . Structures of all novel compounds were confirmed by infrared (IR), proton nuclear magnetic resonance (¹H NMR), carbon nuclear magnetic resonance (¹³C NMR), and mass spectral data. All the synthesized compounds were screened for their antibacterial activities.     

三苯基咪唑类化合物的合成及其紫外、荧光性质研究

设计合成了四种三苯基咪唑类化合物:4,5-二苯基-2-对甲酰基苯基咪唑(2a),4,5-二(2-硝基苯基)-2-对甲酰基苯基咪唑(2b),N-苄基-4,5-二苯基-2-对甲酰基苯基咪唑(2c)和N-苄基-4,5-二(2-硝基苯基)-2-对甲酰基苯基咪唑(2d),并用FT-IR,NMR和MS进行结构表征.在乙酸乙酯-石油醚溶液中获得了2c的单晶,用X射线单晶衍射法测定了其晶体结构,晶体属于三斜晶系,空间群P1,晶胞参数a=0.73796(15)nm,b=0.90136(18)nm,c=1.6644(3)nm,α=86.87(3)°,β=78.25(3)°,γ=89.94(3)°,V=1.0822(4)nm3,Dc=1.272g/cm3,Z=2,F(000)=436,μ=0.077mm-1,R1=0.0459,wR2=0.1303.研究了四种化合物的紫外与荧光性质,发现官能团硝基与苄基的引入,对其吸收峰和发射峰均有不同程度的影响:在紫外光谱中两种官能团均使吸收峰蓝移;在荧光光谱中苄基使发射峰蓝移而硝基使发射峰红移.测定了2a和2c在不同溶剂中的荧光寿命,其中2a在DMSO中寿命最长,为3.18ns.这些光谱性质为研究其双光子吸收、双光子荧光和非线性光学性质奠定了理论和实验基础.     

Diorganotin Complexes with N(4)-Phenylthiosemicarbazones: Synthesis,Spectroscopic Characterization,and Antibacterial Activity

Abstract

The organotin(IV) complexes, SnPh₂L^a (1), SnMe₂L^a (2), SnBu₂L^a (3), SnPh₂L^b (4), SnMe₂L^b (5), SnPh₂L^c (6), SnMe₂L^c (7), and SnBu₂L^c (8) were obtained by reaction of SnR ₂Cl₂ (R = Ph, Me, and Bu) with 1-(5-bromo-2-hydroxybenzylidene)-4-phenylthiosemicarbazide (H₂L^a), 1-((2-hydroxynaphthalen-1-yl)methylene)-4-phenylthiosemicarbazide (H₂L^b), and 1-(2-hydroxy-3-methoxybenzylidene)-4-phenylthiosemicarbazide (H₂L^c). The synthesized complexes have been investigated by elemental analysis, IR, ¹H NMR, and ¹¹⁹Sn NMR spectroscopy. The data show that the thiosemicarbazone acts as a tridentate dianionic ligand and coordinates via the thiol group, imine nitrogen, and phenolic oxygen. The coordination number of tin is 5. The in vitro antibacterial activities of the ligands and their complexes have been evaluated against Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria and compared with the standard antibacterial drugs.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the following free supplemental files: Additional figures and tables]     

The aromatic diboracyclopropenyl (diboriranyl) anion; CB2H3 −: An ab initio study

The most stable structure of CB₂H₃ ^–, as established computationally, is the aromatic diboracyclopropenyl (diboriranyl) anion (5), while open-chainC _2v, isomer H₂BCBH (7) is only 3 kcal/mol higher in energy at the QCISD(T)/6-311 +G^**//MP2/6-31+G^*+ZPE (HF/6-31 +G^*). The 47-kcal/mol barrier between cyclic,5, and open-chain,7, structures suggests that both of them may be observed. The aromatic stabilization energy of the diboriranyl anion (18 kcal/mol) is half the value in the isoelectronic cyclopropenium ion, C₃H₃ ⁺. The computed, by IGLO method (5a), and experimental (6a) chemical shifts,(¹³C) and(¹¹B), agree within 4 ppm range. The theoretical vibrational frequencies of the most stable isomers,5 and7, are presented for experimental verification of these species.     

Synthetic Studies on Sialoglycoconjugates 104: Synthesis of Kdn-Lewis X Ganglioside Analogs Containing Modified Reducing Terminal and L-Rhamnose in Place of L-Fucose 1 2

Abstract

KDN-Le^x ganglioside analogs (10, 13, 16 and 19) containing the modified reducing terminal and L-rhamnose in place of L-fucose have been synthesized. Glycosidation of methyl 2,3,4-tri-O-benzyl-1-thio-α-L-rhamnopyranoside (1) with 2-(trimethylsilyl)ethyl O-(2-acetamido-4,6-O-benzylidene-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-benzyl-α-D-galacopyranoside (2), followed by reductive ring opening of the benzylidene acetal, gave 2-(trimethylsilyl)ethyl O-(2,3,4-tri-O-benzyl-α-L-rhamnopyranosyl)-(1→3)-O-(2-acet-amido-6-O-benzyl-2-deoxy-β-D-glucopyranosyl)-(1→3)-O-(2,4,6-tri-O-benzyl-β-D-galactopyranosyl)-(1→4)-2,3,6-tri-O-benzyl-β-D-glucopyranoside (4). The tetrasaccharide 4 was coupled with methyl O-(methyl 4,5,7,8,9-penta-O-acetyl-3-deoxy-D-glycero-α-D-galacto-2-nonulopyranosylonate)-(2→3)-2,4,6-tri-O-benzoyl-1-thio-β-D-galactopyranoside(5), using dimethyl(methylthio)sulfonium triflate (DMTST), to give the hexasaccharide 6, which was converted into compound 11 in the usual manner. Compounds 8 and 11 were transformed, via bromination of the reducing terminal, radical reduction, O-deacylation and saponification of the methyl ester, into the desired KDN-Le^x hexasaccharides (10, 13). On the other hand, glycosylation of 2-(tetradecyl)hexadecanol with α-trichloroacetimidates 14 and 17, afforded the target ganglioside analogs 16 and 19.

     

15N, 31P,and 13C NMR Spectroscopy of N-Arylsulfonyl-and N-Arylcarbonyl-P,P,P-triphenylphospha-λ-Azenes. Substituent Effects and Electronic Structure

Abstract

The ¹⁵N, ³¹P and ³¹C NMR spectra of several series of phospha-λ⁵-azenes are reported. For the N-arylsulfonyl-P,P,P-triphenylphospha-δ⁵-azene series (R-C₆H₄N-SO₂-PPh₃), the ³¹P chemical shifts, various ¹³C chemical shifts and ¹J_PN were observed to correlate linearly with the Hammett σ constants. Interestingly, the ¹⁵N chemical shifts did not correlate acceptably with any σ or with the Taft dual substituent parameter equation, and 1J_PC was invariant with substituent. For the N-arylcarbonyl-P,P,P-triphenylphospha-λ⁵-azene series (R-C₆H₄-CO-N=PPh₃), δ_31P and various δ_13C's were observed to linearly correlate with the δ constants, while δ_15N, ¹J_PN and ¹J_PC correlated with both the σ and σ constants. For the N-phenyl-P,P,P-triarylphospha-λ⁵-azene series [Ph-N=P(C₆H₄-R)₃] the best correlations were observed between ³¹P, ¹⁵N and several ¹³C chemical shifts and the σ constants.     

Syntheses and crystal structures of new mononuclear and binuclear ruthenium complexes supported by salicylaldimine ligands

Treatment of Ru₃(CO)₁₂ with salicylaldimines [2-HOC₆H₄-CH?=N–C₆H₄-4-R] [R?=?Me; Cl; Br; OMe; CF₃] in refluxing toluene gave three novel binuclear ruthenium carbonyl complexes {[µ-?²-2-OC₆H₄-CH=N-C₆H₄-4-R)][µ-?²-2-CH₂-OC₆H₄][µ-?-NH-C₆H₄-4-R]}Ru₂(CO)₄ [R?=?Me (1), Cl (2), Br (3)] and three mononuclear carbonyl complexes [2-OC₆H₄-CH=N-C₆H₄-4-R][2-OC₆H₄-CH₂NH-C₆H₄-4-R]Ru(CO)₂ [R?=?Me (4), OMe (5), CF₃ (6)], respectively. The structures of 1–6 were fully characterized using IR and NMR spectroscopy, elemental analysis and single-crystal X-ray diffraction. These results suggest that the substituent group on the phenyl of salicylaldimine has a significant effect on the structure of the Ru complex.

     

Studies on the manganese and copper complexes derived from chiral Schiff base: synthesis,structure, cytotoxicity and DNA/BSA interaction

Abstract

Three new manganese and copper complexes, [Mn(ONO-(S)L¹)₂] (1), [Cu(ONO-(R)L²)]₄·2CH₃OH (2), and [Mn₃(ONO-(S)L³)₄(OAc)₄(H₂O)₂] (3), {[H₂L¹ = (S)-2-phenyl-2-(2-hydroxy-5-chlorobenzylideneamino)ethane-1-ol], H₂L² = (R)-2-(2-hydroxy-5-chlorobenzylideneamino)butane-1-ol] and H₂L³ = (S)-2-phenyl-2-(2-hydroxy-3-methoxybenzylideneamino)ethane-1-ol]}, have been synthesized. The crystal structures of 1–3 were determined through single-crystal X-ray diffraction. The structure of mononuclear 1 shows a six-coordinate octahedral geometry around the manganese ion. Complex 2 is a five-coordinate tetranuclear copper complex with the central Cu atoms adopting distorted square pyramidal geometry. Complex 3 shows a trinuclear structure with the six-coordinate Mn ions surrounded by four L³ ligands and acetate ions. The in vitro cytotoxicity screening revealed that the 1–3 had substantial cytotoxicity against three cancer cell lines (HepG2, MDA-MB-231, and A549), even higher than that of cisplatin. Inspiringly, 2 derived from (R)-Schiff base ligand H₂L² was more potent against MDA-MB-231 cells. Interaction of 1–3 with calf-thymus DNA (CT-DNA) has been investigated using UV-vis, viscosity and thermal denaturation experiments. It was found that 1 binds with DNA through intercalation while 2 and 3 interact with DNA probably through groove-binding and electrostatic mode. In addition, the capability of the complexes to bind with bovine serum albumin was monitored using some spectral techniques. The metal ions, chiral and nuclearity have significant influences on the properties of the title compounds.     

ON THE PHOSPHORUS-31 CHEMICAL SHIFTS OF SUBSTITUTED TRIARYLPHOSPHINES

Abstract

The ³¹P chemical shifts of eleven (4-ZC₆H₄)₃P compounds show a slight correlation with the Hammet [sgrave]para constant of Z. The unusually large upfield chemical shifts of (2-ZC₆H₄)₃P compounds are attributed to an extreme “gamma” effect caused by the restricted conformations due to the steric influence of the ortho substituents. Chemical shifts are given for about thirty triarylphosphines, and group contributions to phosphine chemical shifts are listed for twenty-one aryl groups.     

Synthesis,structures, catalytic,and anticancer activities of some coordination compounds involving two new triazole derivatives

Five N-heterocyclic carboxylate-based coordination complexes, [Co(L¹)₂(H₂O)₂]·2H₂O (1), [Cd(L¹)₂(H₂O)₂]·2H₂O (2), [Co(L²)(H₂O)₃] (3), [Ni(L²)(H₂O)₃] (4), and [Cu₂(L²)₂(H₂O)₂] (5), have been synthesized and characterized by elemental analysis, IR spectroscopy, Powder X-ray diffraction, thermogravimetric analyses, and single-crystal X-ray crystallography, where HL¹ is 2-((5-amino-1H-1,2,4-triazol-3-yl)thio)acetic acid and H₂L² is 2-((5-amino-1-(carboxymethyl)-1H-1,2,4-triazol-3-yl)thio)acetic acid. In these complexes, the hydrogen bonds (H-bonds) play an important role in their packing structures. Complex 1 has nine H-bonds showing a 3-D sqc38 topology. Complex 2 has 17 H-bonds exhibiting a 3-D hxl network. Complexes 3 and 4 are isomorphic, both of which possess ten H-bonds to present a 3-D btc topology. Complex 5 with eight H-bonds forms a 2-D sq1 structure. In addition, complex 3 catalyzes the decolorization of methyl orange. Meanwhile, 1, 3, and 5 show certain anticancer activities to inhibit the growth of HepG2 cells.     

Tricarbonylchromium complexes with phenalene. Synthesis, structure, and thermal rearrangements

The reaction of phenalene with Cr(CO)₃Py₃/BF₃·OEt₂ afforded a mixture of two isomeric complexes, tricarbonyl(6a,7-9,9a,9b-·⁶-phenalene)chromium (1) and tricarbonyl(3a,6a,9b,4-6-·⁶-phenalene)chromium (2). Deprotonation of the mixture of compounds1 and2 followed by treatment with MeI, BuⁿI, or D₂O gave complexesexo-1-R-1 (3–5: R=Me (3), Buⁿ (4), or D (5)). The molecular geometry of complex3 was established by X-ray structural analysis. Heating of complex5 in toluene or C₆F₆ at 90–110 °C resulted in redistribution of deuterium among positionsexo-1,endo-1, and 3 in the resulting complexes of types1 and2 via sigmatropic shifts of the H _exo and H _endo atoms in the nonaromatic ring as well asvia inter-ring migrations of the tricarbonylchromium group. In the case of3, the methyl label is distributed among positionsexo-1 and3 to form isomeric complexes with similar structures (exo-1-Me-2 (6), 3-Me-2 (7), and 3-Me-1 (8), respectively)via processes analogous to those observed in the case of isomerization of compound5 (except for migration of the H _exo atom). The mechanisms of these rearrangements are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1863–1880, October, 1997.     

Synthesis,crystal structure and antibacterial activity of manganese(III) and cobalt(III) complexes containing pentadentate Schiff bases of a common amine and thiocyanate

Abstract

Four new mononuclear Schiff base manganese(III) and cobalt(III) complexes viz. [Mn(L¹)(NCS)] (1), [Mn(L²)(NCS)] (2), [Co(L³)(NCS)] (3), and [Co(L⁴)(NCS)]·0.5CH₃OH·0.5H₂O (4), containing thiocyanate as a common pseudohalide ion are reported. The pentadentate Schiff base ligands H₂L¹, H₂L², H₂L³, and H₂L⁴ were obtained by the condensation of substituted salicylaldehydes with N-(3-aminopropyl)-N-methylpropane-1,3-diamine. The syntheses of the complexes have been achieved by the reaction of manganese(II) perchlorate or cobalt(II) perchlorate with the respective Schiff bases in the presence of thiocyanate in methanol medium. Complexes 1–4 have been characterized by microanalytical, spectroscopic, single-crystal X-ray diffraction and other physicochemical studies. Structural studies reveal that 1–4 adopt nearly similar structures containing the MN₄O₂ (M?=?Mn, Co) chromophore in which each central M(III) ion adopts a distorted octahedral geometry. Weak intermolecular H-bonding interactions are operative in these complexes to bind the molecular units. The antibacterial activity of 1–4 and their constituent Schiff bases has been tested against some common bacteria.     

Construction of Cd(II) complexes based on 2-(1H-imidazol-1-methyl)-1H-benzimidazole and 1,4-benzenedicarboxylate

Three new Cd(II) complexes incorporating both 2-(1H-imidazol-1-methyl)-1H-benzimidazole (imb) and 1,4-benzenedicarboxylate (bdic^2?), [CdCl(bdic)_1/2(imb)₂]_n (1), {[Cd(bdic)(imb)(H₂O)]·DMF·2H₂O}_n (2), and [Cd(bdic)(imb)]·3H₂O}_n (3), have been prepared and structurally characterized by single crystal X-ray diffraction. Bdic^2? anions connect the?Cd-imb-Cd-imb?chains leading to a 2-D structure of 1. Bdic^2?(A) and bdic^2?(B) anions link the binuclear [Cd₂(imb)₂(H₂O)₂] units forming a 2-D structure of 2. Complex 3 features a 2-D structure involving supramolecular “double-layer” motifs. IR spectra and thermogravimetric curves are consistent with the results of the X-ray crystal structure analysis; 1–3 exhibit good fluorescence in the solid state at room temperature.     

Electron delocalization in mixed-valence butadienediyl-bridged diruthenium complexes

We report electrochemical and spectroelectrochemical investigations on the butadienediyl-bridged diruthenium complexes [{Ru(PPh₃)₂(CO)Cl}₂(μ-C₄H₄)] (1), [{Ru(PEt₃)₃(CO)Cl}₂(μ-C₄H₄)] (2), and [{Ru(PPh₃)₂(CO)Cl(NC₅H₄COOEt-4)}₂(μ-C₄H₄)] (3). All these complexes are oxidized in two consecutive one-electron steps separated by 315 to 680 mV, depending on the co-ligands. The first oxidation is a chemically and electrochemically reversible process whereas the second varies from nearly reversible to irreversible at room temperature. We have generated and investigated the mixed-valence monocations and observed CO band shifts of ca 25 cm⁻¹ and the appearance of new bands in the visible regime at ca 720 to 800 and 430 to 450 nm. The lower-energy band which tails into the near infrared has been assigned as a charge-resonance (or intervalence charge-transfer) absorption and used to estimate the electronic coupling parameter H _AB. Our investigations point to valence delocalization for 2 ⁺ , and nearly delocalized behavior for 1 ⁺ and 3 ⁺ . Even the complex with the smallest potential splitting is, however, fully delocalized on the longer ESR timescale, as is evident from the coupling pattern of the solution spectrum. Overall IR band shifts on full oxidation and the hyperfine splittings for 1 ⁺ argue for charge and spin delocalization onto the bridging C₄H₄ ligand. This issue has also been addressed by quantum chemical calculations employing DFT methods. Geometry optimizations at each oxidation level reveal inversion of the C–C bond pattern from a short–long–short to a long–short–long alteration and a bis(carbenic) structure at the dication stage. All spectroscopic features such as IR band shifts, average g-values and g-tensor anisotropies are fully reproduced by the calculations. Presented at the 3rd Chianti Electrochemistry Meeting, July 3.–9.2004, Certosa di Pontignano, Italy     

Syntheses and crystal structures of four lanthanide complexes based on two tri-protonated hexacarboxylic acids of 1,2,3,4,5,6-cyclohexane-hexacarboxylic acid and mellitic acid

Four lanthanide complexes with two tri-protonated hexacarboxylic acids [1,2,3,4,5,6-cyclohexane-hexacarboxylic acid (H₆chhc) and mellitic acid (H₆Mel)], [Pr(H₃chhc)(DMF)₃(H₂O)]·H₂O (1), Nd(H₃chhc)(DMF)₃ (2), [Er(H₂O)₈]·(H₃Mel)·9(H₂O) (3), and [Yb(H₂O)₈]·(H₃Mel)·8.5(H₂O) (4), have been synthesized in solution at room temperature and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal structures of 1 and 2 are made up of a (4⁴, 6²) 2-D network extended infinitely parallel to the (1?0?0) plane. The H₃chhc^3? anions assume a cis-e,a,e,a,e,a-conformation with the central ring in chair-shaped configuration. In 3 and 4, the H₃Mel^3? as counter ions are interconnected by hydrogen bonds to form 2-D organic supramolecular layers. The coordination modes and abilities of H₆chhc and mellitic acid are discussed and compared. The luminescences of 1–4 have been investigated.     

Green and efficient synthesis of 1H-indazolo[1,2-b] phthalazine-1,6,11(13H)-triones using ZrO(NO3)2.2H2O as a novel catalyst and theoretical study of synthesized compounds

The one-pot three-component synthesis for the preparation of 1H-indazolo[1,2-b] phthalazine-1,6,11(13H)-triones through condensation of phthalimide, hydrazine monohydrate, dimedone, and aromatic aldehydes in the presence of a novel catalytic amount of ZrO(NO₃)₂.2H₂O at reflux conditions in water has been reported. Quantum theoretical calculations for the three structures of compounds ( 5a , 5b , and 5c ) were performed using the G3MP2, LC-ωPBE, MP2, and B3LYP methods with the 6-311 + G** basis set. After optimizing the structures, geometric parameters were obtained and experimental measurements were compared with the calculated data. The structures of the products were confirmed by IR, ¹H NMR, ¹³C NMR, and elemental analysis. IR spectra data and ¹H NMR and ¹³C NMR chemical shifts computations of the 1H-indazolo[1,2-b]phthalazine-1,6,11(13H)-trione derivatives in the ground state were calculated. Frontier molecular orbitals, total density of states, thermodynamic parameters, and molecular electrostatic potentials of the title compounds were investigated by theoretical calculations. Molecular properties such as the ionization potential (I), electron affinity (A), chemical hardness (η), electronic chemical potential (μ), and electrophilicity (ω) were investigated for the structures. Consequently, there was an excellent agreement between experimental and theoretical results.     

Synthesis and Characterization of Hg(II) Complexes with 2-Subsituted Benzothiazole Thiophosphates

Some complexes of 3-methyl-2-benzothiazolylidenamido thiophosphoryl dichloride (L₁), (3-methyl-2-benzothiazolylidenamido)–bis-(diethylamido) thiophosphate (L₂), 3-benzyl-2-benzothiazolylidenamido thiophosphoryl dichloride (L₃), and (3-benzyl-2-benzothiazolylidenamido)–bis-(diethylamido) thiophosphate (L₄) have been synthesized by a reaction with mercuric chloride in a 1:1 ratio. The complexes have been characterized by elemental analysis, electrical conductivity, and mass and IR spectral studies. The stability constants of these complexes have also been determined by a spectrophotometric technique and compared with zinc complexes of the previously discussed ligands.     

Synthesis of Four Spacer-Containing Trisaccharides with the 4-0-(β-L-Rhamnopyranosyl)-D-glucopyranose Unit in Common,Representing Fragments of Capsular Polysaccharides from Streptococcus Pneumoniae Types 2, 7F, 22F,and 23F

Abstract

The synthesis is reported of 3-aminopropyl 3-O-[4-O(β-L-rhamnopyranosyl)-β-D-glucopyranosyl]-α-L-rhamnopyranoside (34), 3-aminopropyl 2-acetamido-3-O-[4-0-(β-L-rhamnopyranosyl)-β-D-glucopyranosyl]-2-deoxy-β-D-galactopyranoside (37), 3-aminopropyl 3-O-[4-O-(β-L-rhamnopyranosyl)-α-D-glucopyranosyl]-α-D-galactofuranoside (41), and 3-aminopropyl 4-O-[4-O-(β-L-rhamnopyranosyl)-β-D-glucopyranosyl]-β-D-galactopyranoside (45). These are spacer-containing fragments of the capsular polysaccharides of Streptococcus pneumoniae type 2, 7F, 22F, and 23F, respectively, which are constituents of Pneumovax^© 23. 2,3,4-Tri-O-benzyl-α-L-rhamnopyranosyl bromide was coupled to l,6-anhydro-2,3-di-(O-benzyl-β-D-glucopyranose (3). Opening of the anhydro ring, removal of AcO-1, and imidation of l,6-anhydro-2,3-di- O-benzyl-4-O-(2,3,4-tri-O-benzyl-β-L-rhamnopyranosyl)-β-D-glucopyranose (4β) afforded 6-O-acetyl-2,3-di-O-ben-zyl-4-O-(2,3,4-tri- O-benzyl-β-L-rhamnopyranosyl)-αβ-D-glucopyranosyl trichloroacet-imidate (7αβ). Condensation of 7αβ with 3-N-benzyloxycarbonylaminopropyl 2-O-ben-zyl-5,6-O-isopropylidene-α-D-galactofuranoside (26), followed by deprotection gave 41 Opening of the anhydro ring of 4 p followed by debenzylation, acerylauon, removal of AcO-1, and imidation yielded 2,3,6-tri-(9-aceryl-4-O-(2,3,4-tri-0-acetyl-P-L-rharnnopyran-.-osyl)-α-D-glucopyranosyl trichloroacetimidate (11). Condensation of 11 with 3-N-bcn-zyloxycarbonylaminopropyl 2,4-di-O-benzyl-α-L-rhamnopyranoside (18), with 3-N-bcn-zyloxycarbonylaminopropyl 2-acetamido-4,6-O-benzylidene-2-deoxy-β-D-galactopyran-oside (21), or with 3-N -benzyloxycarbonylaminopropyl 2-O-acetyl-3-O-allyl-6-O-benzyl-β-D-galactopyranoside (31), followed by deprotection afforded 34, 37, and 45, respectively.