溴化镁催化合成2-(2′,6′-二甲基-1′,5′-庚二烯基)-4,5-二甲基-1,3-氧硫杂环戊烷

研究了柠檬醛与3-巯基-2-丁醇直接脱水缩合反应合成标题化合物的工艺条件。研究表明,与对甲苯磺酸、氯化钙、三氯化铁及硫酸铜相比,溴化镁作催化剂,产率高,反应条件温和,副反应少,产物后处理简便。当溴化镁用量占柠檬醛用量的0.68%(按物质的量计量),柠檬醛与3-巯基2-丁醇物质的量比为1∶1时,产率可达到78%。反应产物进行了气相色谱、红外光谱、气质联用分析。

Synthesis and Crystal Structure of N-[1-(4-Chlorophenyl)-1,4-dihydro-4-oxe-6-methylpyridazine-3-carbonyl]-N'-benzoylhydrazine

The title compound N-[1-(4-chlorophenyl)-1,4-dihydro-4-oxe-6-methylpyridazine- 3-carbonyl]-N(-benzoylhydrazine was prepared by the reaction of 1-(4-chlorophenyl)-1,4- dihydro-4-oxe-6-methylpyridazine-3-carboxylic acid with chloroformate ethyl ester and benzoyl hydrazine in the presence of triethylamine. The crystal structure ([C19H15ClN4O3]2·C2H5OH, Mr =811.67) has been determined by X-ray crystal structural analysis. The crystal is monoclinic, space group P21/c, with unit cell parameters a=13.296(3), b=17.155(3), c=17.459(3)?,β=98.959(4), Z=4, V=3934(1) ?3, Dc=1.371g/cm3, F(000)=1688, μ(MoKα)=0.226 mm-1, R=0.0495, wR=0.1348 for 3345 observed reflections (I >2σ(I)). The hydrogen bonds N(3)－H…O(1) , N(7)－H…O(4), and N(8)－H…O(2) can be observed.

One-pot synthesis of a hierarchical microporous-mesoporous phosphotungstic acid-HKUST-1 catalyst and its application in the selective oxidation of cyclopentene to glutaraldehyde

A hierarchical microporous-mesoporous metal-organic framework of HKUST-l（Cu）-encapsulated phosphotungstic acid （HPW） material, referred to as HPWs@Meso-HKUST-1, is prepared by a one-pot synthesis method using cetyltrimethylammonium bromide as the supramolecular template. The addition of HPWs to the synthesis mixture of hierarchical porous HKUST-1 results in the direct encapsulation of HPWs inside the mesopores of the HKUST-1 structure, with a homogeneous distribution over the HKUST-1 crystals, which is confirmed by XRD, FT-IR, N2 adsorption, UV-Vis DRS, and TEM. FT-IR-CO adsorption experiments indicated that additional Lewis acid sites were present in the HPWs@Meso-HKUST-1 sample. The novel heterogeneous catalyst demonstrates excellent catalytic performance for the selective oxidation of cyclopentene （CPE） to glutaraldehyde CGA） using tert-butyl hydroperoxide and acetonitrile （MeCN） as the oxidant and solvent, respectively. The high activity of the catalyst is attributed to the mesostructure of the catalyst and the nature and appropriate abundance of the HPWs--being highly dispersed with the addition of Lewis sites. After a reaction for 36 h, the 30% wt% HPWs@Meso-HKUST-1 catalyst exhibits a CPE conversion of 92.5% and a high GA yield of 73%. Furthermore, the HPWs@Meso-HKUST-1 material is sufficiently stable to prevent the leaching of HPWs, and behaves as a true heterogeneous catalyst that can be repeatedly recycled without sustaining a loss of activity and selectivity in the selective oxidation of CPE.

Structural Characterization and Thermal Properties of 1-Amino-1- ethylamino-2,2-dinitroethylene

1-amino-1-ethylamino-2,2-dinitroethylene （AEFOX-7） was synthesized by the reaction of 1,1- diamino-2,2-dinitroethylene （FOX-7） and ethylamine aqueous solution at 92 ℃. The the- oretical investigation on AEFOX-7 was carried out by B3LYP/6-311＋＋G^＊＊ method. The IR frequencies and NMR chemical shifts were performed and compared with the experimental results. The thermal behavior of AEFOX-7 was studied with differential scanning calorimetry and thermal gravity-derivative thermogravimetry methods, and can be divided into a melting process and an exothermic decomposition process. The enthalpy, apparent activation energy and pre-exponential factor of the exothermic decomposition reaction were obtained as 374.88 kJ/mol, 169.7 kJ/mol, and 10^19.24 s^-1, respectively. The critical temperature of thermal explosion of AEFOX-7 is 145.2 ℃. The specific heat capacity of AEFOX-7 was determined with micro-DSC method and theoretical calculation method, and the molar heat capacity is 214.50 J/（mol K） at 298.15 K. The adiabatic time-to-explosion of AEFOX-7 was calculated to be a certain value between 1.38-1.40 s. The thermal stability of AEFOX-7 is much lower than that of FOX-7.

Biphasic Catalytic Hydroformylation of 1-Dodecene in Micellar System with Cationic Gemini Surfactants

The promotion effect of cationic gemini surfactants for the hydroformylation of 1-dodecene in the organic/aqueous biphasic catalytic system is reported. The hydroformylation reaction in the presence of gemini surfactant occurred with higher turnover frequency and higher selectivity for linear aldehyde than using conventional monomeric surfactant CTAB.

Photocatalytic hydrogen-evolution dimerization of styrenes to synthesize 1,2-dihydro-1-arylnaphthalene derivatives using Acr^+-Mes and cobaloxime catalysts

We report a hydrogen-evolution dimerization of styrenes via the synergistic merger of Acr＋-Mes photocatalyst and cobaloxime proton reduction catalysts. By utilizing this dual catalyst system, 1,2-dihydro-1-arylnaphthalene derivatives can be directly constructed from commercially available styrenes. Our reaction proceeds smoothly under mild conditions without the need for oxidants or hydrogen atom transfer reagents, and the sole byproduct is hydrogen gas. Mechanistic investigation suggests that the reaction is initiated by photoinduced electron transfer under visible-light irradiation.

Preliminary Exploration of the Reactor Configuration for Hydroformylation of 1-Dodecene Catalyzed by Water Soluble Rhodium Complex

Hydroformylation of 1-dodecene was studied in a biphasic systemusing water-soluble rhodium complex [RhCl(CO)(TPPTS)_2] as catalystin the presence of cetyl trimethyl ammonium bromide as surfactant toenhance the reaction rate. Efforts were devoted to improve theperformance of hydroformylation by exploring reactor configurationwhich enhanced the mixing, dispersion and interphase mass transfer.Experiments were carried out in a 0.5 L autoclave at the totalpressure of 1.1 Mpa and temperature from 363 K to 373 K.

Tri(4-methoxybenzyloxyl)(pentamethylcyclopentadienyl)titanium/Modified MAO Catalyzed Polymerization of 1-Butene

Tri(4-methoxy-1-benzyloxyl)(pentamethylcyclopentadienyl)titanium(Cp*Ti(OBzOCH3)3) in conjunction with modified methylalumoxane(mMAO) was an efficient catalyst for the living polymerization of butene-1. The steric and highly electron-releasing nature of the catalyst was probably responsible for the resulting polymers with high molecular weight and narrow molecular weight distribution(Mw/Mn=1.25 to 1.36). The effects of polymerization conditions on the catalytic activity, molecular weight and stereo-regularity of the products were investigated in detail. Especially, the content of TMA in MAO used in polymerization of butene-1 had a profound influence on polymer microstructure. The structural properties of the polybutene-1 product were characterized by 13 C NMR, GPC, DSC and WAXD. The results indicated that the polybutene-1 was isotacticity-rich(at 0 ℃, [mmmm] reached up to 60.3%) and the relative content of methylene pentad sequences [mmmm] of the polymer increased with a decreasing temperature.

X-ray Structure of 1- (3' -Phenyl-4' -morpholinyl-2' 5' - dithiole-1' - ylidene)-3, 4-biscarboethoxy-2-thionaphthalene

The title compound (C28H27NO5S3, Mr= 553. 69) was prepared bythe reaction of a-thiobenzoylthioformmorholine with diethyl acetylene dicarboxylate.The crystal is monoclinic, space group P21/n with a= 9. 160(3), b= 17. 726(3), c=16. 602(3) A ; β= 100. 375(13)°; V=2651. 4(10) A3, Z=4, Dc= 1. 387 g/cm3, μ(MoKa) =0. 319 mm-1, F(000) =1160, R=0. 0428, wR(F2) =0. 0910 for 2438 observed reflections (I>2(I)). X-ray analysis reveals that interatomic distances for C(5)-C(6), C(13)-C(14) and C(21)-C(22) are 1. 331(4), 1. 351(4), 1. 344(4)A respectively, which show that they are normal C=C double bonds. All S-C bondlengths are similar to typical S-C single bonds (1. 75 - 1. 78 A ). The five-membered ring A (C(5) -C(6) -S(2)-C(13) -S(1) ) (Fig. 1) and six-membered ringB (C(14) -C(15) -C(20) -C(21)-C(22)-S(3) ) (Fig. 1) adopt the flat twist conformation. Furthermore, the morpholine ring adopts chair conformtion.

Process Design for Separating C4 Mixtures by Extractive Distillation

C4 components are useful in industry and should be separated as individuals. A new process was proposed to separate them by extractive distillation, with the advantages of low equipment investment, energy consumption and liquid load in the columns. One principle to improve the extractive distillation process was put forward. Moreover, the analysis of operation state of the new process was done. There were eight operation states found for the whole process, but only one operation state was desirable. This work provides a way to effectively separate C4 mixtures and helps the reasonable utilization of C4 resource.