A Convenient Synthesis of 2-Arylnaphtho[1,2-d]oxazole Derivatives Promoted by Triethylamine

A variety of 2-arylnaphtho[ 1,2-d]oxazole derivatives were efficiently synthesized in moderate to high yields by the reaction of aromatic aldehydes with 1-amino-2-naphthol derivatives in the presence of triethylamine in refluxing ethanol in air. Seven new 2-arylnaphtho[1,2-d]oxazole derivatives were obtained and characterized by the spectral data and elemental analysis. In addition, the X-ray crystal structures of 2-[4-（N,N-dimethylamino）phenyl]naphtho[ 1,2-d] oxzole （3d） and 1, 1＇-bis（naphtho[ 1,2-d]oxazol-2-yl）ferrocene （3n） have been determined.     

Theoretical Studies on Reaction Mechanism of CH3SO with NO

The potential energy surface （PES） of CH3SO radical with NO reaction has been studied at MP2/6-311G（2df, p） and QCISD/6-311G（2df, p） levels. Geometries of the reactants, transition states （TS） and products were optimized at B3LYP/6-311G （d,p） level. The geometries of the transition states were found for the first time. The calculated results show that the reaction can proceed via singlet-state or triplet-state PES. Because of the high energy barrier of triplet surface, the singlet surface reactions are dominant. The topological analysis of electron density shows that there are two kinds of structaral transition states （the bifurcation-type ring structure transition state and the T-shaped conflict structure transition state） in the titled reaction. The total electronic density of the reactants, TS and products and the spin electronic density on the triplet surface were also discussed in this paper.     

Synthesis of Fluoroalkylated Heterocycles via the Reaction of 3-（1-Hydropolyfluoroalkenyl）-l-oxo-2,4,1-benzoxazines with Dinucleophilic Reagents

The reaction of 3-（1-hydropolyfluoroalkenyl）-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was investigated. 7-Fluoroalkyl-2,3-dihydro- 1,4-diazepine[ 1,2-d]quinazolin- 11-ones 2, 2-fluoroalkylisoxazolo[3,2-b]quinazolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane, hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.     

An Efficient Synthesis of Highly Optically Active 4-Substituted-2（5H）-furanones from Chiral 3-Bromo-2（5H）-furanone

Highly optically active 4-substituted-2(5H)-furanones 6a-6j were obtained in good yields with de≥98% by the tandem Michael addition/elimination reaction of chiral 3-bromo-2(SH)-furanone (4a), which was conveniently prepared starting from 2-furaldehyde under mild conditions. The products were identified on the basis of their satisfactory elemental analysis and spectroscopic data of IR, UV, ^1H NMR, ^13C NMR and mass spectra. The stereochemistry and absolute configuration of this type of compounds were established by the X-ray crystallographic study. The reaction provided a short and efficient synthesis of the interesting highly optically active 4-subsdtuted-2(5H)-furanones containing an active pyrimidine and a purine base group.     

Synthesis, Characterization and Properties of Tri-substitute Potassium Salt of Trinitrophloroglucinol

The title complex [K3（TNPG）·（H2O）2]n was synthesized by the reaction of the aqueous solutions of trinitrophlomglucinol （TNPG） with KHCO3. The complex was characterized by elemental analysis and FTIR spectroscopy, and its single crystal structure was determined by X-ray diffraction analysis. The structural analysis demonstrates that two different coordination modes of K cations [K（1） and K（2）] are around TNPG^3- anions in complex [Ka（TNPG）·（H2O）2]n, where the coordination numbers are eight. All K atoms coordinate with O atoms of phenolic hydroxyl group and nitro-group simultaneously. The thermolysis of the [Ka（TNPG） · （H2O）2]n has been investigated by using differential scanning calorimetry （DSC） and thermogravimetry-derivative thermogravimetry （TG-DTG） at a heating rate of 10 ℃/min. The thermal decomposition processes of the title complex were comprised of one endothermic dehydration stage and one exothermic decomposition stage in 270-320℃, and the final decomposition residue contained KNC. Impact and friction sensitivity results of the complex revealed its sensitive nature towards mechanical stimuli. The experiments verified that the complex has some characteristics of explosive.     

两个新颖的联环十二烷衍生物的合成及结构表征

2-（2＇-Oxo-3＇-oximidocyclododecyl） cyclododecanone （1） and 2-（1＇-hydroxylcyclododecyl） cyclododecanone （2） were synthesized and characterized. The conformation analysis was carried out based on the NMR, molecular mechanics calculation and X-ray diffraction. The conformation of two cyclododecyl moieties of both 1 and 2 was found to be the [3333]-2-one or [3333] square conformation both in the crystal state and the solution. The dihedral angle between carbonyl and the oxime double bond of the ring B is 180°in the crystal of 1. The protons or hydroxyl group of carbon atoms to link the two cyclododecyl moieties of 1 and 2 constitute dihedral angles of 174°in the crystal, and 175°in the solution, and the C-C 6 bond between two cyclododecyl moieties can not freely rotate in the solid state and the solution. In addition, compound 2 was the first example of a-comer-anti-monosubstituted cyclododecanone. synthesis     

3－烷基-4-羟基-2-噻唑烷硫酮-4-羧酸乙酯的一锅煮合成

Ethyl 3-alkyl-4-hydroxy-2-thioxothiazolidine-4-carboxylates were prepared in excellent yields from the reaction of corresponding primary amines with carbon disulfide and ethyl 3-bromo-2-oxopropanoate in the presence of anhydrous potassium phosphate in DMF at room temperature within 1 h. The structures of the highly functionalized products were corroborated spectroscopically （IR, ^1H NMR, ^13C NMR, EI-MS） and by elemental analyses. A plausible mechanism for such type of cyclization was proposed.     

Synthesis,Structure and Quantum Chemical Study on the Organotin Complex [Di（2,4,6-trichlorobenzyl）]tin Bis（quinoline-2-formate）

The title compound was prepared by the reaction of di（2,4,6-trichlorobenzyl） stannic chloride with quinoline-2-formate and characterized with elemental analysis, ^1H NMR, IR and X-ray diffraction methods. It crystallizes in monoclinic, space group P21/n with a = 1.3138（3）, b = 1.8756（4）, c = 1.4599（3） nm, β = 92.731（3）°, V = 3.5933（12） nm^3, Z = 4, Dc = 1.795 g/cm^3, μ（MoKa） = 1.425 mm^-1, F（000） = 1920, R = 0.0778, wR = 0.2286 （for Ⅰ〉 2σ（Ⅰ）） and R = 0.0932, wR = 0.2415 （for all data）. The independent reflections were 6359, among which 5030 were observed （Ⅰ〉 2σ（Ⅰ）） and used in the succeeding refinement. Structural analysis indicates that Sn is in a distorted octahedral coordination environment, and a three-dimensional network could be observed via intermolecular hydrogen bonds. Finally, the stability, frontier orbital composition and energy of the title compound were discussed with Lanl2dz basis set and G98W program.     

邻位吡啶自由基多通道分解反应的动力学和反应机理研究

Utilizing Gaussian94 program package, all species involved in decomposition reactions of o-pyridyl radical were optimized fully at B3LYP/6-311＋＋G^＊＊ level. Intrinsic reaction coordinate calculations were employed to confirm the connections of the transition states and products, and transition states were ascertained by the number of imaginary frequency （0 or 1）. The reaction mechanism was elucidated by the vibrational mode analysis and electronic population analysis, and the reaction rate constants were calculated with transition state theory.     

Synthesis and electrochemical properties of 2,6-bis（6-aryl-[1,2,4]- triazolo[3,4-b][1,3,4]-thiadiazole-3-yl）pyridines

By the condensation of 2,6-bis（4-amino-5-mercapto-[1,2,4]-triazoles-2）pyridine with aromatic acid in the presence of phosphorus oxychloride. Compounds of 2,6-bis（6-aryl-[1,2,4]-triazolo[3,4-b][1,3,4]-thiadiazole-3-yl）pyridines were synthesized. Their structures were confirmed by IR, ^1H NMR spectroscopies and elemental analysis. Their electrochemical behavior and cyclic voltammogram also were be studied. The results showed that they have high ionization potentials and good affinity.     

1,2‐Bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile and Vinyl Ethers: Cyclic Ketene Imines on the Pathway to 1 : 2 Cycloadducts

(E)‐ and (Z)‐1,2‐bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile (BTE; (=E)‐ and (Z)‐1,2‐bis(trifluoromethyl)but‐2‐enedinitrile) were reacted with an excess of methyl vinyl ether, used as solvent, and furnished 1 : 2 adducts 6 (54%) and cyclobutanes 3 as 1 : 1 adducts (41%). The four diastereoisomeric bis‐adducts 6 (different ratios from (E)‐ and (Z)‐BTE) are derivatives of 1‐azabicyclo[4.2.0]oct‐5‐ene; X‐ray analyses and ¹⁹F‐NMR spectra revealed their structures. Since the cyclobutanes 3 are resistant to vinyl ether, the pathways leading to mono‐ and bis‐adducts must compete on the level of the intermediate l,4‐zwitterions 1 and 2 . The latter either cyclize to the cyclobutanes 3 or to six‐membered cyclic ketene imines 8 which accept a second molecule of vinyl ether to yield the bis‐adducts 6 . The occurrence of the highly strained ketene imines 8 gains credibility by comparison to stable seven‐membered cyclic ketene imines recently reported.     

Synthesis and characterization of three dinuclear copper(I) complexes of 1,2‐bis(diphenylphosphino)‐1,2‐dicarba‐closo‐dodecaborane

Three dinuclear copper(I) complexes, [Cu₂(µ‐Cl)₂(1,2‐(PPh₂)₂‐1,2‐C₂B₁₀H₁₀)₂]·2CH₂Cl₂ ( 1 ), [Cu₂(µ‐Br)₂(1,2‐(PPh₂)₂‐1,2‐C₂B₁₀H₁₀)₂]·2THF ( 2 ) and {Cu₂(µ‐I)₂[1,2‐(PPh₂)₂‐1,2‐C₂B₁₀H₁₀]₂} ( 3 ) have been synthesized by the reactions of CuX (X = Cl, Br and I) with the closo ligand 1,2‐(PPh₂)₂‐1,2‐C₂B₁₀H₁₀. All these complexes were characterized by elemental analysis, FT‐IR, ¹H and ¹³C NMR spectroscopy and X‐ray structure determination. Single crystal X‐ray structure determinations show that every complex contained di‐µ‐X‐bridged structure involving a crossed parallelogram plane formed by two Cu atoms and two X atoms (X = Cl, Br, I). The geometry at the Cu atom was a distorted tetrahedron, in which two positions were occupied by two P atoms of the PPh₂ groups connected to the two C atoms of carborane (Cc), and the other two resulted from two X atoms which bridged the other Cu atom at the same time. To the best of our knowledge, this is the first example of copper(I) complexes with 1,2‐diphenylphosphino‐1,2‐dicarba‐closo‐dodecaborane as ligand characterized by X‐ray diffraction. The catalytic property of the complex 3 for the amination of iodobenzene with aniline was also investigated. Copyright © 2005 John Wiley & Sons, Ltd.     

[Hg2(μ‐bpe)(μ‐OAc)2(μ‐SCN)2]n,a New Two‐Dimensional Coordination Polymer Involving Three Simultaneously Bridging Ligands: 1,2‐Bis(4‐pyridyle)ethene,Acetate, and Thiocyanate

A new mercury(II) complex of 1,2‐bis(4‐pyridyle)ethene (bpe) with anionic acetate and thiocyanate ligands has been synthesized and characterized by elemental analysis, IR, ¹H NMR and ¹³C NMR spectroscopy. The single crystal X‐ray analysis shows that the complex is a two‐dimensional polymer with simultaneously bridging 1,2‐bis(4‐pyridyle)ethane, acetate and thiocyanate ligands and basic repeating dimeric [Hg₂(μ‐bpe)(μ‐OAc)₂(μ‐SCN)₂] units. The two‐dimensional system forms a three‐dimensional network by packing via π‐π stacking interactions.     

1,2‐Bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile: Enol Ethers and Ketene Acetals as Cycloaddition Partners

(E)‐ and (Z)‐1,2‐bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile ((E)‐ and (Z)‐BTE, resp., =(E)‐ and (Z)‐2,3‐bis(trifluoromethyl)but‐2‐enedinitrile) were used as a stereochemical probe in studying (2+2) cycloadditions of acceptor with donor alkenes. The additions to methyl (E)‐ and (Z)‐propenyl ether gave rise to the eight conceivable cyclobutanes 8 , although in different ratios in reactions of (E)‐ and (Z)‐BTE. The ¹⁹F‐NMR data served the structural assignment and the quantitative analysis. The mechanistic discussion is based on rotations and ring closures of the assumed 1,4‐zwitterionic intermediates. Dimethylketene dimethyl acetal, methylketene dimethyl acetal, and ketene diethyl acetal show an increasing rate in their reactions with BTE as well as in the equilibration of the cycloadducts.     

Rapid Synthesis of 3‐Aminoimidazo[1,2‐a]Pyridines and Pyrazines

p‐Toluenesulfonic acid catalyzed the one‐pot, three‐component synthesis of 3‐aminoimidazo[1,2‐a]pyridines and pyrazines through a condensation reaction of a 2‐aminoazine, an aldehyde, and an isocyanide at room temperature. This methodology affords a number of 3‐aminoimidazo[1,2‐a]pyridines in reasonable yields and short reaction times without any significant optimization of the reaction conditions.     

An Efficient Synthesis of Spiro‐oxindole Derivatives by Three‐Component Reactions in Water

An efficient synthesis of (3S)‐1,1′,2,2′,3′,4′,6′,7′‐octahydro‐9′‐nitro‐2,6′‐dioxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carbonitrile is achieved via a three‐component reaction of isatin, ethyl cyanoacetate, and 1,2,3,4,5,6‐hexahydro‐2‐(nitromethylidene)pyrimidine. The present method does not involve any hazardous organic solvents or catalysts. Also the synthesis of ethyl 6′‐amino‐1,1′,2,2′,3′,4′‐hexahydro‐9′‐nitro‐2‐oxospiro[3H‐indole‐3,8′‐[8H]pyrido[1,2‐a]pyrimidine]‐7′‐carboxylates in high yields, at reflux, using a catalytic amount of piperidine, is described. The structures were confirmed spectroscopically (IR, ¹H‐ and ¹³C‐NMR, and EI‐MS data) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2).     

Efficient Synthesis of New Tetracyclic Benzofuro[3,2-d]-imidazo[1,2-a] pyrimidine-2,5-(1 H,3 H)-diones

The aza‐Wittig reaction of iminophosphorane ( 1 ) with aromaic isocyanates gave carbodiimides ( 2 ), which were allowed to react further with (‐amino ester in the presence of a catalytic amount of sodium ethoxide to give selectively new tetracyclic benzofuro[3,2‐d]imidazo[1,2‐a]pyrimidine‐2,5‐(1H,3H)‐diones ( 5 ) in good yields. X‐ray structure analysis of 5i verified the proposed structure and the reaction selectivity.     

One‐Pot Synthesis of Novel Pyrrolo[1,2‐a]quinoxaline‐4(5H)‐ones Using Benzene‐1,2‐diamine,Acetylenedicarboxylates, and β‐Nitrostyrene Derivatives

The reaction between a variety of o‐phenylenediamines (=benzene‐1,2‐diamines), dialkyl acetylenedicarboxylates, and derivatives of nitrostyrene (=(E)‐(2‐nitroethenyl)benzene) in the presence of sulfamic acid (SA; H₃NSO₃) as catalyst led to the corresponding pyrrolo[1,2‐a]quinoxaline‐4(5H)‐one derivatives in high yields.     

A Facile Synthesis of Oxoindenothiazine and Dioxospiro(indene‐2,4′‐thiazine) Derivatives from (Substituted ethylidene)hydrazinecarbothioamides

(E)‐2‐[2‐(1‐Substituted ethylidene)hydrazinyl]‐5‐oxo‐9b‐hydroxy‐5,9b‐dihydroindeno[1,2‐d][1,3]‐thiazine‐4‐carbonitriles and (E)‐5‐oxo‐[(E)‐(1‐substituted ethylidene)hydrazinyl]‐2,5‐dihydroindeno[1,2‐d][1,3]thiazine‐4‐carbonitriles have been obtained from the reaction of 2‐(substituted ethylidene)hydrazinecarbothioamides with 2‐(1,3‐dioxo‐2,3‐dihydro‐1H‐inden‐2‐ylidene)propanedinitrile ( 1 ) in ethyl acetate solution. However, (Z)‐6′‐amino‐1,3‐dioxo‐3′‐substituted‐2′‐[(E)‐(1‐phenylethylidene)hydrazono]‐1,2′,3,3′‐tetrahydrospiro(indene‐2,4′‐[1,3]thiazine)‐5′‐carbonitriles were observed during the reaction of N‐substituted‐2‐(1‐phenylethylidene)hydrazinecarbothioamides with ( 1 ). The structure assignment of products has been confirmed on the basis of ¹H‐, ¹³C‐NMR, and mass spectrometry, as well as theoretical calculations.     

Influence of Secondary Bonds on the Network Assembly and Property in Lead(II) 3‐Sulfobenzoate Coordination Polymer

A unique 3‐D Pb^II coordination polymer containing ligands 1,2‐bis(4‐pyridyl)ethylene (bpe) and 3‐sulfobenzoate (3‐sb), [Pb(3‐sb)(bpe)_0.5]_n ( 1 ) has been synthesized by hydrothermal reaction and characterized by elemental analysis, IR, TGA, ¹H NMR, powder X‐ray analysis, and fluorescent spectrum. The single‐crystal X‐ray analysis shows that eight coordination bonds can be divided as five primary bonds and three secondary bonds. The secondary bonds largely enhance the solid stability and provide a high‐dimensional network assembly. The complex also displays strong fluorescent property.