Thermal Behavior, Non-isothermal Decomposition Reaction Kinetics of Copper(Ⅱ) Salt of 4-Hydroxy-3,5-dinitropyridine and Its Application in Propellant

The thermal behavior and kinetic parameters of the major exothermic decomposition reaction of the title compound in a temperature-programmed mode were studied by means of TG-DTG and DSC. The critical temperature of thermal explosion was calculated. The effect of the title compound on the combustion characteristic of composition modifier double base propellant containing RDX was explored with a strand burner. The results show that the kinetic model function in differential forms, the apparent activation energy(E a) and the pre-exponential factor(A) of the major exothermic decomposition reaction are 3(1-α)[-ln(1-α)] 2/3, 190.56 kJ/mol and 10 13.39 s -1, respectively. The critical temperature of thermal explosion of the compound is 353.08 ℃. The kinetic equation of the major exothermic decomposition process of the title compound at 0.1 MPa could be expressed as dα/dT=10 14.65(1-α)[-ln(1-α)] 2/3 e -2.2920×104/T. As an auxiliary catalyzer, the title compound can help the main catalyzer of lead salt of 4-hydroxy-3,5-dinitropyridine to accelerate the burning rate and reduce the pressure exponent of RDX-CMDB propellant.

The Solvent Effect on the Chemoselectivity of Palladium-catalyzed Oligomerization of 3,3-Dimethyl-1-butyne

The chemoselectivities of PdCl2 and CuCl2-catalyzed oligomerization of 3, 3-dimethyl-butyne: 1, 3, 5-tri-tert-butylbenzene, 2, 2, 7, 7-tetramethyl-3, 6-dichloro-3, 5-octadiene and 2, 2, 7, 7- tetramethyl-3, 5-octadiyne were obtained, respectively, by regulating the polarity of the solvent.

Stereoselective Synthesis of δd-Selanyl Allylic Alcohols by Hydrozirconation of Propargyl Selenides

Hydrozirconation of propargyl selenides afford (E)-3-selanyl vinylzirconocenes chlorides 2. Intermediates 2 reacted with aldehydes to obtain d-selanyl allylic alcohols.

Catalytic HgCl_2-Samarium System Induced Reductive Coupling of Nitriles with Nitro Compounds

The intermolecular coupling of a nitro group with a cyano group mediated by a Sm(Hg) amalgam prepared from metal samarium powder and catalytic mercury dichloride was studied.

A ZINDO/1-CI Study of Substituted Triphenylamines for Use as Charge Transfer Materials

Electronic spectra of substituted triphenylamines are investigated in this paper by time dependent perturbation theory and ZINDO/1-CI calculation.

Ultrasonic-enhanced Stereoselective Debromination of vic-Dibromides to Alkenes with Metallic Zinc Powder in Aqueous Media

Carbon-carbon double bond functional groups are often protected through a popular bromination/debromination method because of their reactivity. An ultrasonic-enhanced stereoselective debromination of vic-dibromides with metallic zinc powder in aqueous media has been developed, which generates E-alkenes with excellent yields. The reactivity of vic-dibromides decreases in the order of 1,2-dibromo-1,2-diphenylethane>1,2-dibromo-1-phenylethane>1,2-dibromo-1,2-dialkylethane.

Efficient Debromination of Vicinal a, b-Dibromo Carboxylic Acid Derivatives with the Sm/HOAc System

The ? ?vicinal dibromo carboxylic acid and its derivatives were debrominated with Sm/HOAc system to afford the corresponding cinnamic acid and its derivatives in good yields under mild conditions.

Studies on the Synthesis of Penazetidine A, an Alkaloid Inhibitor of Protein Kinase C

A convergent asymmetric synthesis of (2S, 3R, 4S, 12'R)-3-hydroxy-2-hydroxymethyl- 4-(12' -methyloctadecyl)-N-(p-tolylsulfonyl)-azetidine, a key precursor of penazetidine A, has been achieved by starting from divinylcarbinol.

Synthesis and Crystal Structure of N-phenylthiocyano-phenyl-thioformamide bis(η_5-methylcyclopentadienyl)(tetrahydrofuran)Samarium(Ⅲ)

The insertion reaction of phenyl isothiocyanate into the Ln S bond was studied. Phenyl isothiocyanate reacted with [(CH 3C 5H 4) 2Sm(SPh)(THF)] 2 to give the title complex, (CH 3C 5H 4) 2Sm[SC(SPh)NPh](THF), in good yield, which was characterized by elemental analyses, IR, 1H NMR and X ray structural determination. The crystal structure analysis of complex shows that samarium atom is coordinated by two CH 3C 5H 4 groups, one O atom of THF, and N and S atoms from the SC(SPh)NPh ligand to form a distorted trigonal bipyramidal geometry.

The Preparation of α-Phosphonovinylzirconocenes and their Application in the Stereospecific Synthesis of α-Halo-1 -alkenylphosphonates

Hydrozirconation of 1-alkylnylphosphonates gives the organozirconium(Ⅳ) complexes 2 in syn-addition way. Complexs 2 was trapped with NCS, NBS or I2 to afford stereodifined α-halo-1-alkenylphosphonates in moderate to high yields.

Stereospecifical Preparation of (E)-a-Stannyl-1-alkenylphosphonates and their Application in Stille Reaction

The palladium catalyzed hydrostannation of 1-alkenylphosphonates gives the (E)-α-stannyl 1-alkenylphosphonates 2 stereospecifically. Compounds 2 can occur Stille coupling reaction to afford a, b-disubstituted vinylphosphonates with the retention of the configuration.

Convenient Solid-phase Synthesis of Benzothiazole Derivatives

Resin-bound cyclic malonic ester l reacted with aryl isothiocynate, then was treated with bromine, followed by cleavage from the resin under perchloric acid to give benzothiazoles 4.

Synthesis and Characterization of the Chiral Skeleton Cluster [NiRuMo(CO)_5(μ_3-S)(η~5-C_5H_5)(η~5-C_5H_4COCH_3)]

The new chiral cluster [NiRuMo(CO)5(m3-S)(h5-C5H5)(h5-C5H4COCH3)] 3 was synthesized by the reaction of precursor [CoRuMo(CO)8(m3-S)(h5-C5H4COCH3)] 1 with NiCp2 2 in refluxing THF. It was characterized by C/H elemental analysis, IR and 1H NMR. Molecular structure of cluster 3 was determined by single-crystal X-ray analyses. Crystal data: triclinic, space group P with the following crystallographic parameters: a = 7.9606(8), b = 8.5604(9), c = 14.779(2) , a = 93.908(2), b = 105.057(2), g = 101.463(2)? C17H12O6MoNiRuS, Mr = 600.05, Z = 2, V = 945.5(2) 3, Dc = 2.108 g/cm3, m = 2.568 mm-1, (2q )max ≤ 56.48, F(000) = 584,the final R = 0.0380 and wR = 0.0674 for 2995 observed reflections with I > 2.00s(I).

Formation of α,α'-Bis(substituted benzylidene)cycloalkanones from Masked Aldehydes Promoted by Samarium(III) Triiodide

Diacetates 1 and N-[(1-benzotriazol-l-yl)alkyl]amides 2, both masked forms of aldehydes, could undergo deprotection and condensation with cycloalkanones in a one-pot procedure promoted by samarium(III) iodide (SmI3) to afford α,α'-bis(substituted benzylidene) cycloalkanones in good yields.

Samarium-promoted Chemoselective Reduction of Aromatic Nitro Compounds in Ionic Liquid

bState Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China The differently substituted aromatic nitro compounds were chemoselectively reduced by Sm/HOAc system in an ionic liquid medium to afford aromatic amines. Under these conditions the other substituents, such as -X, -CHO, -COOH, -CN, -NHTos and -alkyl, remained intact. The notable advantages of this reaction are its mild conditions, simple operation, short reaction time, high yields and easy recycling of ionic liquid.

One-Pot Syntheses of 3,4-Dihydropyrimidine-2(1H)-thiones Catalyzed by La(OTf)_3

A general and practical procedure for the syntheses of 3,4 dihydropyrimidine 2(1 H ) thiones by a one pot condensation of aldehyde, β ketoester or β diketone and thiourea using La (OTf) 3 as the catalyst is described. Mild reaction conditions, excellent yields as well as the environmentally friendly character of La(OTf) 3 make it an important alternative to the classic acid catalyzed Biginelli's reaction.

Recent Advances in Organic Reactions Catalyzed by Lanthanide(III) Complexes

Lanthanide compounds have been attracting much attention in organic synthesis. Chiral Ln substituted BINOL have been widely studied in several asymmetric organic reactions. LnCl 3 and Ln(OTf) 3 have been expected to serve as Lewis acids and have been applied to many important synthetic reactions in a one pot manner. Ln(O i Pr) 3 exhibits some basic characters, which also can be utilized in some special organic transformation. This article deals with some lanthanides(III) complexes promoted organic reactions, which we have recently developed.

Boron(III) Tribromide or Titanium(IV) Bromide and Lewis Base Promoted Baylis-Hillman Reaction

It was found that, when the Baylis-Hillman reaction of arylaldehydes withmethyl vinyl ketone was carried out at below - 20℃ in the presence of boron (Ⅲ) tribromide ortitanium (Ⅳ) bromide using a catalytic amount of Lewis base such as amine, the brominated compoundsand the Baylis-Hillman adducts could be obtained as the major products in good yields for variousaryl aldehydes. But at room temperature, the elimination products were the major products. Inaddition, the palladium catalyzed allylic substitution reactions of the e-limination products werealso examined.

Synthesis, Structure and Reactivity of Lanthanocene Complexes

A variety of lanthanocene complexes, e.g. chlorides, hydrocarbyls, amides, hydrides and divalent derivatives, were synthesized by using a series of designed cyclopentadienyl, indenyl and fluorenyl ligands with ring bridges or dornor functionalized sidearms. X Ray crystallographic analyses reveal the formation of intramolecular coordination bonds between central metals and heteroatoms (O, N) in sidearms or bridging chains. Some applications of these complexes are also discussed in this account.