Synthesis and Characterization of Poly（ether amide）s Containing Bisphthalazinone and Ether Linkages

A novel aromatic diacid, 4, 4′-bis[2-(4-carboxyphenyl)phthalazin- 1-one-4-yl]-bisphenyl ether III, containing bisphthalazinone and ether linkages was prepared from nucleophilic substitution of p-chlorobenzonitrile with the bisphenol-like monomer I, followed by alkaline hydrolysis of the intermediate dinitrile II. A series of poly(ether amide)s containing bisphthalazinone and ether linkages derived from diacid III and aromatic diamines were synthesized by one-step solution condensation polymerization using triphenyl phosphite and pyridine as condensing agents. Moreover, the properties of poly(ether amide)s including thermal stability,solubility and crystallinity were also studied.     

Synthesis of Methylenebis(Phosphonate) Analogues of Nucleotide Coenzymes. A Novel Coupling Mechanism

Synthesis of P¹, P²-disubstituted methylenebis(phosphonate)s as inhibitors of inosine monophosphate dehydrogenase is presented.     

Synthesis and Characterization of Modified Polyimides: Poly(Urethane-Imide)

Abstract

Poly(urethane-imide)s (PUIs) were prepared by the Diels–Alder (DA) reaction of 5-(2-furanylmethylcarbamato)-1-[1-(2-furanylmethylcarbamatomethyl)]-1, 3, 3, -trimethylcyclohexane (FFCH) with various bismaleimides. The DA reaction was carried out in 1, 4-dioxane as the solvent as well as in bulk. This was followed by aromatization of the polytetrahydrophthalimide intermediate in the presence of acetic anhydride. All polymers were characterized by elemental analysis, IR spectral studies, and thermogravimetry. The PUIs exhibited moderate thermal stability. FFCH and bismaleimide were polymerized (at 145 ± 10°C) by an in-situ DA reaction into thermally stable PUIs-glass fiber composites (i.e., laminates) and were characterized by their chemical resistance and mechanical properties.     

New Size-Expanded Fluorescent Thymine Analogue: Synthesis,Characterization, and Application

Here, the synthesis, photophysical characterization, and application of a new size-expanded thymine nucleoside, ^diox T , is described. ^diox T has desirable qualities as a T surrogate, including excellent quantum yield (0.36) and high environmental sensitivity. When incorporated into single- and double-stranded DNA, ^diox T showed excellent photophysical characteristics including a high quantum yield (average 0.20), and unlike BgQ, demonstrated dependence on neighboring bases without significant destabilization of the duplex. Interestingly, the matched base pair of adenine (A) and ^diox T has the unique property that it exhibits higher fluorescence than mismatched base pairs, and ^diox T has self-quenching effects. As one example of the possible applications of these promising features, single nucleoside polymorphism typing is demonstrated for discrimination of A by using ^diox T . The results suggest that ^diox T can be used for a broad range of applications in chemical biology.     

ChemInform Abstract: Synthesis and Structural Characterization of an Antiinflammatory Principle Purified from Lindera aggregata.

Linderaggrine A (I) exhibits significant inhibitory effects against the superoxide anion generation.     

Reactions of Cycloaliphatic Thioketones and Their Oxo Analogues with Lithiated Methoxyallene: A New Approach to Vinylthiiranes

Admantanethione smoothly reacted with lithiated methoxyallene at low temperatures yielding the expected allenyl‐substituted thiolate, which upon aqueous work‐up underwent spontaneous 1,3‐cyclization to afford a hitherto unknown methoxy‐substituted vinylthiirane derivative. The analogous reaction with adamantanone led to the corresponding allenyl alcohol that can be isolated and—depending on the conditions applied—either be converted into the corresponding vinyloxirane or into the 2,5‐dihydrofuran derivative. Sterically more crowded thioketones were also combined with lithiated methoxyallene, but in these cases competitive 1,5‐cyclization leading to isomeric dihydrothiophene derivatives was observed. DFT calculations of model intermediates and products show distinct energy differences of the sulfur and the corresponding oxygen compounds. Desulfurization of the adamantanethione‐derived vinylthiirane yielded a methoxy‐substituted 1,3‐diene that was studied in cycloadditions with electron‐deficient dienophiles. Whereas in the case of tetracyanoethylene the corresponding cyclobutane derivative was formed, the reaction with nitrosobenzene provided the expected 1,2‐oxazine derivative. By reductive cleavage of the N? O bond this heterocycle was converted into an unsaturated amino alcohol bearing an adamantane moiety.     

Synthesis and Structural Characterization of a Novel Cyclotetraphosphate

The crystal structure of (2-NH₂-5-ClC₅H₄N)₄P₄O₁₂.6H₂O was determined by X-ray diffraction on a single crystal. This compound crystallizes in an orthorhombic unit cell Pccn with the parameters a = 25,387(7) Å, b = 15,756(6) Å, c = 9,750(5) Å, V = 3900(2) ų, Z = 4, and D _x = 1,605 g.cm^?3. Crystal structure has been determined and refined to R = 0,036, using 7678 independent reflexions. This structure can be described as inorganic layers stacked along a-direction and held together through N-H… O hydrogen bonds, originating from the organic cations, giving rise to three-dimensional H-bonded assemblies. In addition, in this structure there is electrostatic, van der Waal forces and Cl… Cl interaction so as to increase the cohesion of 3D-network. Chemical preparation and characterization by RX diffraction, IR absorption, and thermal analysis are described.     

3-三氯锡基丙酸酯及其配合物的合成与结构表征

合成了4个新的3-三氯锡基丙酸酯Cl3SnCH2CH2COOR(R=环戊基，1；环己基，2 ；环戊甲基，3；环己甲基，4)，并通过其与二丁基亚砜(L^1)、2，2’-联吡啶 (L^2)、1，10-菲咯啉(L^3)的低热固相反应合成了6个相应的配合物 Cl3SnCH2CH2COOR·L(L=L^1,a;L^2,b;L^3,c).利用元素分析、红外光谱、核磁共振 对其结构进行了表征，并通过X射线单晶衍射测定了1和2的晶体结构，二者均为具 有分子内羰基氧原子配位的畸变三角双锥结构．1属于单斜品系，空间群P21/c, a=0.9842(2)nm,b=1.0923(8)nm,c=1.23948(11)nm,β=93.894(15)°,V=1.3294(4) nm^3,Mr=366.23,Z=4.2属于单斜晶系，空间群P21/c,a=1.04443(9)nm,b=1.04823 (7)nm,c=1.28113(9)nm,β=90.953(8)°,V=1.40239(19)nm^3,Mr=380.25,Z=4.     

Synthesis and characterization of new poly(arylene ether)s containing heterocyclic units. II.

A series of new poly(arylene ether)s, containing naphthalene, pyridine, and quinoline units have been prepared by solution condensation polymerization. The synthesis involves nucleophilic displacement of aromatic dihalides with aromatic potassium bisphenates in an anhydrous dipolar aprotic solvent at elevated temperatures. The polymers, having inherent viscosity from 0.24 to 1.32 dL/g, were obtained in quantitative yield, have excellent thermal stability as shown by 10% weight loss temperatures in nitrogen and air (above 450 and 430°C, respectively) and high glass transition temperatures (in the range of 150–220°C). The introduction of quinoline moieties in the polymer backbone positively influences the thermal properties, such as high T_g/T_m ratios. © 1995 John Wiley & Sons, Inc.     

Synthesis of highly fluorescent materials: Isoindole-containing polymers

A series of stable, highly fluorescent and highly phenylated isoindoles have been synthesized by treating the respective o-dibenzoylbenzenes with anilines at 200°C in the presence of a catalytic amount of p-toluenesulfonic acid. The correlation between the emission frequences and the structures of the isoindoles is described. The same reaction has also been used to transform a series of poly(o-dibenzoylbenzene)s into poly(isoindole)s. The resulting polymers have been studied by ¹H-NMR, DSC, TGA, and fluorescence spectra. They are highly fluorescent materials with high molecular weights, high glass transition temperatures, and high thermal stabilities. The tetraphenyl substituted isoindole-containing polymers have a maximum emission around 468 nm, whereas the diphenyl substituted isoindole-containing polymers have their maximum emission around 486 nm. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3293–3299, 1999     

Synthesis,spectral and thermal properties of macrocyclic zinc(II) complexes

The new zinc ternary complexes [Zn(cyclen)NO₃]ClO4 (I), [Zn₂(cyclen)₂(m-nic)](ClO₄)₃ (II), [Zn₂(cyclen)₂(m-pic)](ClO₄)₃ (III) (cyclen=1,4,7,10-tetraazacyclododecane; nic=nicotinic acid; pic=picolinic acid) were synthesized and their spectral and thermal properties were investigated. The compounds were characterized by elemental analysis, IR spectroscopy and TG/DTG, DTA methods. Moreover, the way of coordination of pyridinecarboxylate anions was proposed on the basis of the spectral data and consequently proved with results of X-ray structure analysis. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis of Cyclosporine and Analogues: Structural Requirements for Immunosuppressive Activity

Cyclosporine is a new immunosuppressive drug which was first marketed in 1983 under the trade name Sandimmune®. This compound, an innovation in selective immune modulation, was isolated from a fungal culture and characterized as a cyclic undecapeptide containing a novel amino acid together with several N-methylated amino acids. The new amino acid (4R)-4-[(E)-2-butenyl]-4,N-dimethyl-L -threonine (MeBmt) was the only unknown amino acid of cyclosporine and there had previously been no means for its isolation. For this reason and because it seemed possible that MeBmt could play a significant role in determining the pharmacological activity of cyclosporine, its synthesis in enantiomerically pure form was undertaken. The next step was the development of a total synthesis of cycloporine, which appeared attractive, not only for its intrinsic worth, but also as an important tool for investigating the relationships between structure and immunosuppressive activity. Essential for the immunosuppression are the amino acids MeBmt, Abu, Sar, and MeVal in the positions 1, 2, 3 and 11, but probably also still larger parts of the molecule. Such information could be valuable for finding new chemical leads or drugs with a new activity profile.     

光学纯(S)-2-(苄氧酰氨基)-4-氧代丁酸苄酯的合成和结构表征

以L-蛋氨酸为起始原料,经甲基化、水解、羧基和氨基保护及氯铬酸吡啶嗡盐(PCC)氧化等6步反应,合成了高光学纯度的(S)-2-(苄氧酰氨基)-4-氧代丁酸苄酯。通过1HNMR、IR、MS和mp测试技术表征了其结构;分别用手性柱HPLC和旋光仪法测定了它的化学纯度和光学纯度(ee%值)分别为99.3%和99.5%,产物的总收率为30.0%。     

Alkaline Earth Metallocenes Coordinated with Ester Pendants: Synthesis,Structural Characterization,and Application in Metathesis Reactions

A variety of ester‐substituted cyclopentadiene derivatives have been synthesized by one‐pot reactions of 1,4‐dilithio‐1,3‐butadienes, CO, and acid chlorides. Direct deprotonation of the ester‐substituted cyclopentadienes with Ae[N(SiMe₃)₂]₂ (Ae=Ca, Sr, Ba) efficiently generated members of a new class of heavier alkaline earth (Ca, Sr, Ba) metallocenes in good to excellent yields. Single‐crystal X‐ray structural analysis demonstrated that these heavier alkaline earth metallocenes incorporated two intramolecularly coordinated ester pendants and multiply‐substituted cyclopentadienyl ligands. The corresponding transition metal metallocenes, such as ferrocene derivatives and half‐sandwich cyclopentadienyl tricarbonylrhenium complexes, could be generated highly efficiently by metathesis reactions. The multiply‐substituted cyclopentadiene ligands bearing an ester pendant, and the corresponding heavier alkaline earth and transition‐metal metallocenes, may have further applications in coordination chemistry, organometallic chemistry, and organic synthesis.     

Synthesis and Structural Characterization of new Tri (2-methyl-2- phenylpropyl) tin Carboxylates containing Germanium

Organotincompoundsareextensivelystudiedfortheirbiologicalactivity'.Organogermaniumisanotherkindofelementthathasawiderangeofbiologicalactivity=.Tolinkbiologicalactivepropertiesoforganotinandorganogermaniumcompounds.wehavepreviouslyreportedthebiologicalactivityoftrialkyltingermylpropionates'andanticanceractivityofdibutyltindigermylpropionates'.ItiswellknownthatTorque(his[tri(2-methyl-2-phenylpropyl)tin]oxide)iswidelyusedinagricultureasanacaricide.Inthispaper,asthecontinuationofourpreviouswork"'…     

Oligoagarose-Graft-Polycaprolactone Copolymers: Synthesis and Characterization

In this paper, we combine hydrophilic oligoagarose (DP_n = 10–15), issued from enzymatic degradation of the natural biopolymer agarose, with polycaprolactone, a synthetic biodegradable and hydrophobic polyester. To synthesize these amphiphilic graft copolymers, we use partially acetylated oligoagarose as macroinitiator in combination with tin (II) octanoate for the bulk polymerization of ε-caprolactone. The grafting was confirmed by NMR and SEC which showed a monomodal distribution. After removal of the acetyl protecting groups, copolymers with 30–60% free hydroxyl groups were soluble in water and insoluble in chloroform, thus indicating that they probably adopt micelle-like structures in aqueous solution with a PCL hydrophobic core and spherical oligoagarose side chains.     

Synthesis of ( ) 8-O-Cinnamyl-p-chlorogoniotriol and its Analogues

HowiinolAI',anovellactoneisolatedfromtheethanolicextractsoftherootandsternbarkofGoniolhanlush()TI)iiMerr.(Annoaceae)inourlaboratory.hasbeenshowntopossesssignificantantitullloractivitiestowardhumantumor117vilroandI,71'if'oandfoxytoxlcit}.Recently.wehavesynthesized1anditsderivativeswitllditTerentestergroupsstartingfromcommerciallyavailablea-D-glucoheptonic-y-lactone.Inordertotindtheirrelationshipofstructureandactivityandtosearchfordrugswithmorepotentantitumoractivity.wehavesynthesized( )8-O-…     

倍半萜EnglerinA及其类似物的合成

2008年从东非大戟科属植物Phyllanthus engleri 中分离的吉玛烷型倍半萜(-)-englerin A对6种肾脏癌细胞展示了非常好的抑制活性(GI₅₀:1-87nm),甚至比紫杉醇的抗癌活性高1-2个数量级。这类倍半萜因其结构特点和显著的抗癌活性引起了有机化学界的广泛关注, 短短几年之内,就有多条全合成路线先后被报道。本文主要综述了(-)-englerin A及其类似物的合成进展,按照各个研究小组运用的关键策略加以分类,来阐述他们各自的合成特点。