Synthesis,Optical and Electrochemical Properties of D1–A–D2–A–D1 Type Conjugated Donor-Acceptor Assemblies of Five-Membered Aromatic Heterocycles

Chemistry of Heterocyclic Compounds - Novel conjugated systems of the D1–A–D2–A–D1 type were synthesized based on...     

Four New Isovalertatins M33, D13, D33, and D43, from the Culture Filtrate of Streptomyces luteogriseus

In a program of investigating the chemical constituents of the potentially α-amylase- inhibiting complex, WC670, extracted from the culture filtrate of Streptomyces luteogriseus, we found it contains the known aminooligosaccharides, isovalertatins M03, M…     

Ligusaginoids A–D,four eremophilane-type sesquiterpenoid dimers and trimers from Ligularia sagitta

Four novel highly oxygenated eremophilane-type sesquiterpenoid dimers and trimers with the unique 6/6/5/5 polycyclic skeleton, designated as ligusaginoids A–D (1–4), were isolated from the aerial parts of Ligularia sagitta. Their structures with absolute configurations were determined by a combined method. Moreover, a plausible biosynthetic pathway of 1–4 was also proposed. These compounds showed weak antibacterial activities.     

MAOS of D‐Gluconic Acid,D‐Glucono‐1,4‐ and 1,5‐Lactones,Esters, Hydrazides,and Benzimidazoles Thereof

Microwave‐assisted organic synthesis (MAOS) of D‐gluconic acid can be efficiently done by oxidation of D‐glucose with bromine water, upon irradiation with microwave (MW). It was also used for the conversion of D‐gluconic acid to ethyl D‐gluconate, D‐glucono‐1,4‐ and 1,5‐lactones, gluconyl hydrazide, and gluconyl phenylhydrazide in yields comparable to those obtained by conventional methods, but in much shorter times. A convenient microwave‐mediated condensation of D‐gluconic acid with o‐phenylenediamines provided the respective acyclonucleoside benzimidazole in short time and good yield.      

A New 1D Cadmium Coordination Polymer Based on N- and O-donor Ligands： Synthesis, Structure and Luminescent property

One new cadmium coordination polymer, [Cd(nbdc)(dmpy)]n (1, H2nbdc = 2-nitro- terephthalic acid, dmpy = 5,5′-dimethyl-2,2′-bipyridine) has been synthesized under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis (TGA), and single-crystal X-ray diffraction. Complex 1 is of monoclinic system, space group C2/c with a = 11.7684(9), b = 24.3715(19), c = 13.9898(11) , β = 107.652(2)°, V = 3823.5(5) 3, C20H15N3O6Cd, Z = 8, Mr = 505.75, Dc = 1.757 g/cm3, μ(MoKα) = 1.187 mm-1, F(000) = 2016, the final R = 0.0207 and wR = 0.0560 for 3034 observed reflections with I > 2σ(I). 1 exhibits an interesting one-dimensional double chain structure. Furthermore, the luminescent property of 1 has also been investigated.     

Unified Asymmetric Total Syntheses of (−)-Alotaketals A–D and (−)-Phorbaketal A

The novel tricyclic spiroketal alotane-type sesterterpenoids showed strikingly different biological activities and potency with subtle structural alterations. Asymmetric total syntheses of the tricyclic sesterterpenoids (−)-alotaketals A–D and (−)-phorbaketal A were accomplished [29–31 steps from (−)-malic acid] in a collective way for the first time. The key features of the strategy included 1) a new cascade cyclization of vinyl epoxy δ-keto-alcohols to forge the common tricyclic spiroketal intermediate, 2) a late-stage allylic C−H oxidation, and 3) olefin cross-metathesis to install the different side chains.     

A 2D Lanthanide-organic Framework Based on Inorganic Lanthanum（Ⅲ） Sulfate Skeletons：Synthesis,Structure,and Luminescence and Thermal Properties

A new lanthanum coordination polymer formulated as {[La2(pyda) 2(μ4-SO4) ·5H2O]· 2H2O}n(1,H2pyda = 2,6-pyridine-dicarboxylic acid) has been synthesized from the reaction of H2pyda with lanthanide nitrate in the presence of sulfate as a counter anion. The compound was characterized by elemental analysis,IR spectroscopy and X-ray single-crystal diffraction. It crystallizes in the orthorhombic system,space group Pna21,with a = 18.8558(19) ,b = 6.5831(7) and c = 18.7543(19) . The compound is a 2D hybrid,in which the La(Ⅲ) ions were doubly connected by the carboxylic group of pyda2-ligand to form the La(Ⅲ) dimer followed by being grafted into 1D zig-zag chains which are further connected into a 2D network containing {[La(SO4) ]+}n helical chains. The interchain hydrogen bonding and π-π stacking interactions extended the 2D networks into a 3D supramolecular edifice.     

STELLADELIN D,A NEW CYCLIC UNDECAPEPTIDE FROM STELLARIA DELAVAYI

ＳＴＥＬＬＡＤＥＬＩＮＤ，ＡＮＥＷＣＹＣＬＩＣＵＮＤＥＣＡＰＥＰＴＩＤＥＦＲＯＭＳＴＥＬＬＡＲＩＡＤＥＬＡＶＡＹＩ￥ＹｕＲｕｉＺＨＡＯ；ＪｕｎＺＨＯＵ；ＸｉａｎＫａｉＷＡＮＧ；ＸｉａｏＬｉｎＨＵＡＮＧ；ＨｏｕＭｉｎｇＷＵ；ＣｈａｎｇＸｉａｎｇＣＨＥＮ...     

Toonapolyynes A–D,new polyynes from Toona ciliata

Abstract

Phytochemical investigation on the leaves and twigs of Toona ciliata has led to the isolation of four new polyynes (1–4) and two knowns (5 and 6). Their structures were determined by extensive spectroscopic analysis (MS, UV, IR, and NMR) and Mosher’s method. All compounds were evaluated for their inhibitory activities against HepG2 human tumor cell line but were inactive.     

A New 3D Metal-organic Framework with Tetranuclear Cadmium（II） Clusters： Synthesis,Structure, and Luminescent Property

A unique metal-organic framework [Cd2(L)1.5(μ3-OH)(H2 O)2 ]·2H2 O(1, H2 L = 2,5-dibenzoylterephthalic acid) has been synthesized under hydrothermal conditions, and characterized by single-crystal X-ray diffractions, elemental analyses, IR spectra and fluorescence spectrum. The compound is of triclinic system, space group P1, C33 H27 CdO14, Mr = 870.33, a = 12.2939(17), b = 12.5135(9), c = 13.2046(10), α = 115.3190(10), β = 96.9140(10), γ = 109.7950(10)°, V = 1641.6(3)3, Z = 2, Dc = 1.761 g/cm3, F(000) = 862, μ(MoK) = 1.366 mm-1, Rint = 0.0148, R = 0.0240 and wR = 0.0639 for 5995 observed reflections with I 2σ(I). X-ray analysis shows that the title complex exhibits a 3D framework with(412·63) topology, in which the tetra-nuclear [Cd4(μ3-OH)2 ] clusters act as 6-connected nodes, and the L ligands can be simplified to be linear connectors. Moreover, the thermal stability and fluorescence have been studied in detail.     

A New 1D Zinc Coordination Polymer Constructed by 1-Naphthylacetate and 4,4＇-bpy：Synthesis,Structure and Luminescent Property

One new zinc coordination polymer,[Zn(NAA)2(4,4'-bpy)]n(1,HNAA = 1-naphthaleneacetic acid,4,4'-bpy = 4,4'-bipyridine),has been synthesized under hydrothermal conditions and characterized by elemental analysis,IR spectroscopy,thermogravimetric analysis(TGA),and single-crystal X-ray diffraction.Coordination polymer 1 is of monoclinic system,space group Cc with a = 9.8720(6),b = 16.7397(9),c = 17.0371(12) ,β = 104.8080(10)°,V = 2721.9(3)3,C34H26N2O4Zn,Z = 4,Mr = 591.94,Dc = 1.444 g/cm3,μ(MoKα) = 0.946 mm-1,F(000) = 1224,the final R = 0.0282 and wR = 0.0720 for 3300 observed reflections with I > 2σ(I).1 exhibits an interesting one-dimensional chain structure.Furthermore,the luminescent property of 1 has also been investigated.     

FOUR NEW GLYCOSIDES, LIGUROBUSTOSIDES A, B, C AND D FROM LIGUSTRUM ROBUSTUM

ＦＯＵＲＮＥＷＧＬＹＣＯＳＩＤＥＳ，ＬＩＧＵＲＯＢＵＳＴＯＳＩＤＥＳＡ，Ｂ，ＣＡＮＤＤＦＲＯＭＬＩＧＵＳＴＲＵＭＲＯＢＵＳＴＵＭ￥ＪｕｎＴＩＡＮ；ＨｏｎｇＪｉｅＺＨＡＮＧａｎｄＨａｎＤｏｎｇＳＵＮ．（Ｌａｂｏｒａｔｏｒｙｏｆｐｈｙｔｏｃｈｅｍｉｓｔｒ...     

Synthesis of 3‐Methoxyoxetane δ‐Amino Acids with D‐lyxo,D‐ribo,and D‐arabino Configurations

Starting from 1,2‐isopropylidene‐d‐xylose (1), 3‐methoxyoxetane δ‐amino acids with d‐lyxo, d‐ribo, and d‐arabino configurations were synthesized. The early introduction of an azide function at C‐5 of 1 shortened the synthetic pathway. Ring contraction of the intermediate d‐xylono‐1,4‐lactone 6 via triflation and treatment with base led to the corresponding 3‐methoxyoxetane δ‐amino ester with d‐lyxo configuration 7. The analogous procedure for d‐ribono‐1,4‐lactone 16 furnished a mixture of d‐ribo and d‐arabino esters 17 and 18. Hydrolysis of the methyl esters 7, 17, and 18 to their corresponding δ‐amino acids was successful with LiOH in THF, in contrast to that of their 3‐hydroxy analog 11.      

A straight forward and first total synthesis of Penilumamides B–D

A simple and straight forward first total synthesis of rare lumazine peptides, Penilumamide B, C and D isolated from the marine-derived fungi Aspergillus and Penicillium sp. is described from a common starting material, 1,3-dimethyllumazine-6-carboxylic acid. Penilumamide C was prepared from Penilumamide B by oxidation of the methionine residue to the corresponding sulphone.     

Synthesis of Gibbilimbols A ～ D and Their ( Z )-Isomers

Gibbilimbols (1) were isolated from the leaves of Piper gibbilimbum in Papua New Guinea, which showed cyto toxicity toward KB nasopharyngal cancer cells (EDs0 2～ 8 μg/mL) and antibacterial activity against Staphylococcus epidermidis and Bacillus cereus (MIC 2 ～4 μg/mL). [1] Only two methods were reported for the synthesis of them,one is a coupling of phenolic part with alkyne, followed by reduction of triple bond by Mori. [2]     

4,5-Pyrenocyanine--just another phthalocyanine? A STM and 2D WAXS study

Pyrene-fused tetraazaporphyrins were synthesized from pyrene-4,5-dicarbonitrile precursors using a recently reported procedure as the key step for the asymmetric substitution of pyrene. Metal-free, zinc- and lead-centered pyrenocyanines were obtained and their optical properties as well as their molecular assembly in the solution and bulk phases and at the liquid/solid interface were studied. The characteristic Q-band appears broadened, most likely owing to distortion of the molecule introduced by the steric demand of the angularly extended aromatic residue. The angular annulation does not bathochromically shift the Q-band as far as would have been expected for the linear case. Peripheral substitution with linear and branched alkoxy chains affords solubility of the compounds in organic solvents. The influence of the distinct steric demand of the substituents on aggregation was investigated for metal-centered pyrenocyanines by using temperature-dependent (1)H NMR and UV/Vis spectroscopy. The self-assembly at the liquid/solid interface was studied using scanning tunneling microscopy. The alkoxy substituents facilitate the anchoring of these slightly non-planar molecules on the surface of graphite. Pyrenocyanine molecules form well-ordered 2D arrays in which the molecules are arranged in rows. The angular annulation of the pyrenocyanine residue leads to characteristic adsorption behavior at the liquid/solid interface, in which the molecules adsorb in two different adsorption geometries. The alkoxy side-chains give rise to a discotic columnar superstructure and induce distinct thermotropic behavior. Dependent on the steric demand of the branched chains and the central metal atom, the molecules are rotated with respect to each other to form helical organization.     

1D + 1D → 1D polyrotaxane, 2D + 2D → 3D interpenetrated, and 3D self-penetrated divalent metal terephthalate bis(pyridylformyl)piperazine coordination polymers

Divalent metal coordination polymers containing terephthalate (tere) and bis(4-pyridylformyl)piperazine (bpfp) show diverse and interesting two-dimensional (2D) interpenetrated, three-dimensional (3D) self-penetrated, or one-dimensional (1D) polyrotaxane topological features. Isostructural {[M(tere)(bpfp)(H(2)O)(2)]?4H(2)O}(n) phases (1, Zn; 2, Co) exhibit mutually inclined 2D + 2D → 3D interpenetration of gridlike layers. {[Cd(4)(tere)(4)(bpfp)(3)(H(2)O)(2)]·8H(2)O}(n) (3) possesses a novel 3,4,8-connected trinodal self-penetrated network with (4.6(2))(2)(4(2)6(16)8(7)10(3))(4(2)6(4))(2) topology. [Zn(2)Cl(2)(tere)(bpfp)(2)](n) (4) is the first example of a 1D + 1D → 1D polyrotaxane coordination polymer, to the best of our knowledge. Metal coordination geometry plays a crucial role in dictating the overall dimensionality in this system. Thermal decomposition behavior and luminescent properties of the d(10) configuration metal derivatives are also presented herein.     

A Novel, Simple and Efficient Synthesis of Ferrocenyl Enones and Alkynols

Propargylic alcohols are versatile precursors to many organic molecules including natural products and pharmaceutical compounds.[1] In our continuing interest in the development of practical methods for synthesis of ferrocene derivatives, we decided to investigate the efficiencies of ferrocenylacetylene addition to aromatic aldehydes under t-BuOKcatalyzed condition.[2] Interestingly, we found that the usually reliable coupling reaction between terminal alkyne of type 1 and aromatic aldehydes of type 2 does not furnish the expected propargylic alcohols, but that the isomeric aryl enones 3are found in high yield and very short reaction time (10～20 min). This provided a promising protocol for preparation of ferrocenyl chalcones in a practical, economical and mild sense compared with the traditional method. To the best of our knowledge, this unusual reaction was first observed for the addition of ferrocenylacetylene to aldehyde in a base-catalyzed manner (Eq. 1).     

Potential Biodegradable Implants from ϵ-Caprolactone and D,L-Lactide Copolymers: Synthesis,Properties, and In Vivo Degradation

Random copolymers of ?-caprolactone (CL) and D, L-lactide (DLLA) were synthesized by ring-opening polymerization using stannous octoate as catalyst. The effect of polymerization conditions, such as feeding dose, reaction temperature, polymerization time, and catalyst content on the properties of the copolymers was evaluated to prepare suitable copolymers with controlled properties for biodegradable implant applications. The results showed that the polymerization conditions influenced the thermal and mechanical properties of the copolymers strongly and controllable and tunable properties of random copolymers could be obtained by adjusting the copolymer compositions. The optimum reaction conditions to prepare the CL-DLLA copolymers for implant applications are 30–87 mol.% DLLA content in feeding dose, 110°C reaction temperature, and 24 h polymerization time. The results of in vivo implantation revealed the excellent degradability of CL-DLLA copolymers. Copolymers of CL and DLLA with different compositions and properties would be suitable for the application of biodegradable implants.