A Convenient Method for Synthesis of Novel Cyclic Ethers (1R,2R,3R,5S,7S,9R,12R)-3-(t-Butyldimethylsilyl)oxy-7-methoxymethyl-oxy-2,10-dimethyl-12-oxatricyclo [7.2.1.0~(5,12)] dodecane

Coloradocin, a novel macrolide antibiotic from cultures of Actinoplanes coloradoensis1exhibits activity against pathogenic anaerobic and microaerophilic species2. Because itslow toxicity and substantial oral activity3, , as well as its unusual structure5, several 4research groups initiated approaches towards the synthesis of coloradocin6, whichculminated in the synthesis of 18-deoxynargenicin A1 by Kallmerten et al.7. …     

1,3-Dipolar Cycloaddition of Substituted Benzonitrile Oxide to 5-(R)-(l-Menthyloxy)-2(5H)-furanone

Isoxazoline compounds as key intermediates for construction of natural products have been developed very fast as an hot area in organic synthesis1. 5-(R)-(l-menthyloxy)- 2(5H)-furanone as a valuable chiral synthon has been recently studied for its high stereoselectivity in many reactions2. In this paper, we focused on its reactivity and regioselectivity of the 1,3-dipolar cycloaddition with the substituted benzonitrile oxide3 and several isoxazoline compounds were obtained and characterized…     

Enamine Configuration of 5-Methyl-2-phenyl-4-[（Z）-3-tolylamino-phenylmethylene]pyrazol-3（2H）-one

1 INTRODUCTION In contrast to the old-line academic and practical studies of 1-phenyl-3-methyl-4-benzoyl-5-pyrazo- lone (PMBP) on the metal coordination chemistry[1], the complexes of β-ketoamines derivated from PMBP received little attention due to its complicated com- plexation. However, in recent years, there has a sudden growth of this area as a result of its timely interest in biological activities[2]. Recently, a series of β-ketoamines[3] containing PMBP have been prepared fro…     

利用磁性可回收的Fe_3O_4纳米颗粒催化剂合成苯并咪唑的新方法(英文)

Magnetically recoverable Fe3O4 nanoparticles have been synthesized as a catalyst for the cyclocondensation of 1,2-phenylenediamines with orthoesters under solvent-free conditions.Catalyst loadings can be as low as 1 mol% to give high yields of the corresponding benzimidazole derivative at 80 °C.This green method offers significant advantages in terms of its simplicity,low catalyst loadings,high product yields,and non-toxic nature.The Fe3O4 nanoparticles were characterized by X-ray diffraction,transmission electron microscopy,and Fourier transform infrared spectroscopy.     

Evaluation of Transient Absorption Spectra of N, N, N, N- Tetra - ( p -methylphenyl ) - 4, 4- diamino - 1, 1- diphenyl Ether ( TPDAE ) for Electron Transfer from TPDAE to Fullerenes ( C_(60) / C_(70) ) by Laser Flash Photolysis

Fullerenes C60 and C70 have high electron affinity ( 2.6 - 2.8 ev ) and readily form anions on electronchemical reduction1, which were famous as electron acceptor in photo-excitation because of symmetrical shape, large size, and properties of its p - electron system2. After observation of molecular ferromagnetism3 in the tetrakis (dimethylamino ) ethylene salt of C60 as well as the occurrence of ultra-fast photoinduced electron transfer within the dimethyl aniline - C60 complex4, prompted us…     

STUDY ON THE CHAIN-EXTENDING REACTION OF POLY (ETHYLENE TEREPHTHALATE) WITH 2, 2′-BIS (4H-3, 1-BENZOXAZIN-4-ONE)

2,2'-Bis (4H-3, 1-benzoxazin-4-one) (BBON) has been proved to be an effective chainextender for poly (ethylene terephthalate) (PET). In order to study the reaction mechanismand kinetics of chain-extending reaction, β-bishydroxyethylene terephthalate (BHET) wasselected as model compound. The NMR data, IR spectra and number average molecularweight (M_n) of the products obtained from the reaction of BBON and BHET verify thatBBON is a hydroxyl-reactive extender. The mechanism was discussed. Kinetics dataindicate that extending reaction is a second order reaction, and BBON has high reactivity.The activation energy (E_a) was measured.     

Investigation on Vibrational Spectra and Structures of 4-Mercaptopyridine Monomer and Its Dihydrate

Introduction4-Mercaptopyridine(4MPY)has been always em-ployed as a model molecule and a probe molecule forRaman spectra in many studies because of its specialstructure with two active groups and its excellent signalin a Raman spectrum.Therefore,4MPY has b…     

Synthesis, Properties and Crystal Structure of a Novel Coordinated Polymer:{(H_2en)(H_3O)[(BiPb(C_2O_4)_4(H_2O)_2)]·2(H_2O)}_n

1 INTRODUCTION It is well-known that bismuth and lead display attractive properties as promoting elements in noble metal-based catalysts[1], and thermal decomposition of ammonium metal oxalates can yield crystalline porous materials with a high surface area. This feature makes them attractive as precursors for catalysts and other nanocrystalline oxides[2]. Because of their topology, the oxalates themselves also possess inte- resting properties such as the capability of ion-exchange. The …     

Biotransformation of 14-Deacetoxy-13-oxo sinenxan A by Ginkgo Cell Cultures

Sinenxan A, 2a, 5a, 10b,14b-tetraacetoxy-4(20),11-taxadiene, is a taxoid isolated from the callus cultures of Taxus spp. in high yield (ca. 1~2% of dry weight)1,2. The rich resources and its taxane-skeleton vest it valuable potential for the semisynthesis of paclitaxel or other structurally related bioactive compounds, such as 搒econd -generation?taxoid anticancer agents and taxane-based multidrug resistant anticancer agents3-5. Many remarkable studies on its structural modification by chemi…     

Bis(1-(4-(dimethylamino)benzylidene)-4-phenylthiose micarbaznato)palladium(Ⅱ):Synthesis,Crystal Structure and Its Dual Fluorescence Property

The title compound bis(1-(4-(dimethylamino)benzylidene)-4-phenylthiosemicar-bazato)-palladium(Ⅱ)(PdL2) was obtained by reacting 1-(4-(dimethylamino)benzylidene)-4-phenyl-thiosemicarbazide with dichlorobis(benzonitrile)palladium(Ⅱ) in methanol,and its structure was characterized by single-crystal X-ray diffraction.The crystal of PdL2 was obtained in dimethyl-formamide(DMF) solvent with solvent molecules involved in the cell and crystallizes in the monoclinic system,space group C2 with a = 18.485(15),b = 7.090(5),c = 17.595(11) ,β = 121.21(3)o,V = 1972(2) 3,Z = 2,Mr = 847.40,Dc = 1.427 g/cm3,μ = 0.624 mm-1,F(000) = 880,R = 0.0607 and wR = 0.1358.The Pd atom adopts a distorted square planar coordination geometry with two Pd-N and two Pd-S bonds.The ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via mercapto sulfur and the imine nitrogen atom,which binds to palladium as bidentate N,S-donors forming five-membered chelate rings.The complex formed hydrogen bonding interaction with solvent DMF molecules from the hydrogen of phenylamine to the oxygen of DMF and several intramolecular hydrogen bonds.Pd(Ⅱ) perturbed ligand π-π* transition and metal-to-ligand charge transfer(MLCT) transition are observed in its electronic absorption spectra.The complex exhibits intraligand 1π-π*(IL) state and MLCT state dual fluorescent emissions in organic solvent at room temperature.     

Heterogeneous isomorphism hollow SiGe nanospheres with porous carbon reinforcing for superior electrochemical lithium storage

Silicon is emerging as a promising next-generation lithium-ion battery anode because of its high theoretical capacity and low cost. However, the poor cyclability and inferior rate performance hinder its largescale applications. Here, hollow silicon/germanium(H-SiGe) nanospheres with a binary-active component and heterogeneous structure combined with porous carbon(pC) reinforcing are synthesized as lithium-ion battery anodes. Experimental studies demonstrate that the H-SiGe/pC anodes possess tiny...     

Synthesis and Anti-HIV Activity of Trisubstituted （3＇R, 4＇R）-3＇,4＇-Di-O-（S）-camphanoyl-（＋）-c/s-khenactone （DCK） Analogs

To further explore the potential of DCK analogs as anti-HIV drug candidates, ten new tri-substituted （3＇R,4＇R）-3＇,4＇-di-O-（S）-camphanoyl-（＋）-cis-khellactone （DCK） derivatives （4-13） were designed, synthesized, and evaluated against HIV replication in MT4 cells and H9 lympho- cytes.     

Chemistry of1,16–Dihydroxytetraphenylene and 2,3,9,10–Tetrakis(trimethylsilyl)pentacene

Recently, four tetraphenylenols, as well as several non–substituted and substituted 2,3,9,10–tetrakis(trimethylsilyl)pentacenes were realized in our laboratories. In this presentation, the synthesis, hydrogen bonding properties, and chiral recognition studies of (S)–1,16–dihydroxytetraphenylene (1) and its (R)–enantiomer will be delineated. 1,16–Bis(diphenylphosphino)tetraphenylene (2) was also realized from 1 and was employed in the formation of a stable platinum complex. The synthesis…     

EPR SPECTRA OF THE HIGH Tc SUPERCONDUCTOR YBa_2Cu_3O_7

<正> INTRODUCTION. The research on a series of high T_c Y-Ba-Cu-O superconductors since its dxscovery has been found interesting. Preparations and structural studies concerning this field, as well as some spectroscopic work on the study of the superconductive mechanism have been reported. In this communication, we report the EPR studies of the superconductor YBa_2Cu_3O_7 both at room temperature and at liquid N_2 temperature.     

(Et_4N)_2[Fe_4(SPh)_10] Stimulated S_(RN)1 Reactions of α-Bromonaphth-alene with Pinacolone Carbanion

The studies of the radical chain nucleophilic substitution reaction (SRN1) have been active field in both mechanism and organic synthesis research1-4. The mechanism is a well known process by which a nucleophilic substitution is produced on a non-actived adequated substituted substrate. It is a chain process which involves radicals and radical anions as intermediates. The main steps of this mechanism are sketched in scheme 1. As stimulated methods of initiation step, the photostimulated5-7, …     

以对二甲苯氧化为对苯二甲酸为例简要综述一级C–H键活化(英文)

The oxidation of para‐xylene to terephthalic acid has been commercialised as the AMOCO process(Co/Mn/Br) that uses a homogeneous catalyst of cobalt and manganese together with a corrosive bromide compound as a promoter. This process is conducted in acidic medium at a high tempera‐ture(175–225 °C). Concerns over environmental and safety issues have driven studies to find mild‐er oxidation reactions of para‐xylene. This review discussed past and current progress in the oxida‐tion of para‐xylene process. The discussion concentrates on the approach of green chemistry in‐cluding(1) using heterogeneous catalysts with promising high selectivity and mild reaction condi‐tion,(2) application of carbon dioxide as a co‐oxidant, and(3) application of alternative promoters. The optimisation of para‐xylene oxidation was also outlined.     

热分解双(2-氨基烟酸)锌(Ⅱ)制备的介孔微砖ZnO纳米颗粒的光催化活性(英文)

Hollow microblocks of [Zn(anic)_2], as a novel coordination compound, were synthesized using 2-aminonicotinic acid(Hanic) and zinc(Ⅱ) nitrate tetrahydrate. The chemical composition of the zinc complex, ZnC_(12)H_(10)N_4O_4, was determined by Fourier transform infrared(FTIR) spectroscopy and elemental analysis. The synthesized zinc complex was used as a precursor to produce ZnO nanostructures by calcination at 550 °C for 4 h. Morphological studies by scanning electron microscopy and transmission electron microscopy revealed the formation of porous microbricks of ZnO nanoparticles. N_2 adsorption-desorption analysis showed that the obtained ZnO microbricks possess a mesoporous structure with a surface area of 8.13 m~2/g and a pore size of 22.6 nm. The X-ray diffraction pattern of the final product proved the formation of a pure ZnO composition with a hexagonal structure. Moreover, FTIR analyses showed that the 2-aminonicotinic acid ligand peaks were absent after the calcination step. Diffuse reflectance spectroscopy was used to determine the band gap energy of the produced ZnO and it was about 3.19 eV. To investigate the photocatalytic activity of the porous ZnO nanostructure, a series of photocatalytic tests were carried out to remove Congo red, as a representative toxic azo dye, from aqueous solution. The results show that the product can be used as an efficient photocatalyst for waste water treatment with high degradation efficiency.     

Synthesis and characterization of a new open-framework zinc phosphite (4,4′-(C5H4N)2(CH2)3)·[Zn3(HPO3)4]

Employing 4,4-trimethylenedipyridine as a template,a new two-dimensional zinc phosphite (4,4-(C5H4N)2(CH2)3)· [Zn3(HPO3)4 ] has been prepared at room temperature and characterized by single-crystal X-ray diffraction,FTIR,elemental analysis,powder X-ray diffraction,and thermogravimetric analysis.The compound crystallizes in the monoclinic space group P2 1 /c,with cell parameters,a=9.3309(19),b=14.798(3),c=33.637(7),β=91.11(3),V=4643.8(16) nm 3 and Z=4.The connectivity of the ZnO4 tetrahedra and HPO 3 pseudo pyramids results in infinite corner-sharing 4-membered ring chains as second building units which are further linked by Zn O P bonds to form a 2-D layer that with interesting 8-membered ring channels along the [100] direction.The diprotonated 4,4-trimethylenedipyridine molecules sit in the middle of the layers along the [100] direction and interact with the framework via hydrogen bonds.     

以对二甲苯氧化为对苯二甲酸为例简要综述一级C–H键活化(英文)

The oxidation of para‐xylene to terephthalic acid has been commercialised as the AMOCO process(Co/Mn/Br) that uses a homogeneous catalyst of cobalt and manganese together with a corrosive bromide compound as a promoter. This process is conducted in acidic medium at a high tempera‐ture(175–225 °C). Concerns over environmental and safety issues have driven studies to find mild‐er oxidation reactions of para‐xylene. This review discussed past and current progress in the oxida‐tion of para‐xylene process. The discussion concentrates on the approach of green chemistry in‐cluding(1) using heterogeneous catalysts with promising high selectivity and mild reaction condi‐tion,(2) application of carbon dioxide as a co‐oxidant, and(3) application of alternative promoters. The optimisation of para‐xylene oxidation was also outlined.     

A new efficient route for the synthesis of 4,4′,6,6′-tetra(azido) azo- 1,3,5-triazine

A new method for the synthesis of 4,4′,6,6′-tetra(azido)azo-1,3,5-triazine(TAAT)is described.The key intermediate 4,4′,6,6′- tetra(azido)hydrazo-1,3,5-triazine(TAHT)was synthesized by nucleophilic substitution in the case of sodium azide as nacleophile. N-Bromosuccinide(NBS)was used as oxidant to oxidize TAHT by a tractable operation under mild reaction condition.The target compound TAAT was obtained with a facile process and high overall yield of 81%.The structures of TAAT and its intermediates were identified by spectroscopic methods.