CATALYTIC SYNTHESIS OF α-CYANO-α,β-UNSATURATED SULPHONES IN THE PRESENCE OF ORGANOTELLURIUM OXIDE

Using bis(p-methoxyphenyl)telluroxide(BMPTO)as the catalyst, phenylsulphonyl acetonitrile condensed easily with aromatic aldehydes at room temperature to give -cyano- ,β-unsaturated sulphones in high yields.

Catalytic Synthesis of Tert-Butyl Acetate by Nd_2O_3/Al_2O_3-Nd_2O_3/ZnO

Nd2O3 was used to support Al2O3 and ZnO to prepare a supported solid base catalyst and investigate the effect of catalyst and reaction conditions on the synthesis of tert-butyl acetate. The composited oxide of Nd2O3/Al2O3-Nd2O3/ZnO exhibited excellent catalytic activity for the synthsis of tert-butyl acetate. The molar ratio of tert-butanol to acetic anhydride is 3∶1, the catalyst in total amount of reactant nearly 0.5%, and reaction time 6 h. With the above conditions, yield of the reaction could reach to 65%. The structure of product were verified by the FT-IR, Element analysis, and MS, which proved that the product was tert-butyl acetate.

Ionic liquids-SBA-15 hybrid catalysts for highly efficient and solvent-free synthesis of diphenyl carbonate

Diphenyl carbonate(DPC)is one of the versatile carbonates,and is often used for the production of polycarbonates.In recent years,the catalytic synthesis of DPC has become an important topic but the development of a highly active metal-free catalyst is a great challenge.Herein,a series of ionic liquids-SBA-15 hybrid catalysts with different functional groups have been developed for the synthesis of DPC under solventfree condition,which are effective and clean instead of the metal-containing catalysts.It is found that in the presence of[SBA-15-IL-OH]Br catalyst,methyl phenyl carbonate(MPC)conversion of 80.5%along with 99.6%DPC selectivity is achieved,the TOF value is thrice higher than the best value reported by using transition metal-based catalysts.Moreover,the catalyst displays remarkable stability and recyclability.This work provides a new idea to design and prepare eco-friendly catalysts in a broad range of applications for the green synthesis of carbonates.

Catalytic kinetics of dimethyl ether one-step synthesis over CeO_2–CaO–Pd/HZSM-5 catalyst in sulfur-containing syngas process

CeO_2–CaO–Pd/HZSM-5 catalyst was prepared for the dimethyl ether(DME) one-step synthesis in a continuous fixed-bed micro-reactor from the sulfur-containing syngas. The catalytic stability over hybrid catalyst of CeO_2–CaO–Pd/HZSM-5 was investigated to ensure that the kinetics experimental results were not significantly influenced by induction period and catalytic deactivation. A large number of kinetic data points(40 sets) were obtained over a range of temperature(240–300 °C), pressure(3–4 MPa), gas hourly space velocity(GHSV)(2000–3000 L·kg^(-1)·h^(-1)) and H_2/CO mole ratio(2–3). Kinetic model for the methanol synthesis reaction and the dehydration of methanol were obtained separately according to reaction mechanism and Langmuir–Hinshelwood mechanism. Regression parameters were investigated by the method combining the simplex method and Runge–Kutta method. The model calculations were in appropriate accordance with the experimental data.

Solvothermal Synthesis and Photocatalytic Performance of Bi_2S_3 Hierarchical Nanostructure

The synthesis of Bi2S3 hierarchical nanostructure was reported by a solvothermal reaction using ethylene disulfhydrate as the sulfur source and chelating reagent. The as-synthesized samples were characterized by X-ray diffraction（XRD）, Raman, X-ray photoelectron spectroscopy（XPS）, scanning electron microscopy（SEM） and photoluminescence（PL）. The XRD, Raman, and XPS data confirmed that the as-synthesized sample belongs to orthorhombic phase Bi2S3. The SEM observations displayed that Bi2S3 hierarchical nanostructure assembled from nanorods. A 410 nm ultraviolet photoluminescence（PL） emission of as-synthesized Bi2S3 was observed when the sample was excited with wavelength of 320-330 nm. The Bi2S3 hierarchical nanostructure also shows a significant enhancement of photocatalytic capability toward degrading methyl orange（MO） under UV light, the photodegradation of MO reaches 95% within 180 min.

STUDIES ON THE SYNTHESIS OF BAIMUXINOL BY CATALYTIC HYDROGENATION OF DEHYDROBAIMUXINOL

Baimuxinol, a 4-hydroxymethyl agarofuran isolated from Aquilaria Sinensis, was synthsizd. The stereoselectivity of catalytic hydrogenation of dehydrobaimuxino and its derivatives was studied.

Seed-induced synthesis of small-crystal TS-1 using ammonia as alkali source

Small-crystal TS-1 was synthesized via a seed-induced approach using ammonia as the alkali source and tetrapropylammonium bromide as an auxiliary structure-directing agent. The TS-1 samples were characterized using X-ray diffraction, N2 adsorption-desorption, Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectroscopy, scanning electron microscopy, and ultraviolet-visible spectroscopy. The use of the colloidal seed reduced the crystal size, and an appropriate amount of silicalite-1 seed assisted Ti incorporation into the TS-1 framework. This method reduces the cost of TS- 1 synthesis because a significantly smaller amount of tetrapropylammonium hydroxide is used. The catalytic performance of the synthesized small-crystal TS-1 samples in cyclohexanone ammoximation was better than that of bulk TS-1 as a result of improved diffusion and a larger number of active tetrahedral Ti centers.

Nitrogen-rich carbon for catalytic activation of peroxymonosulfate towards green synthesis

Nitrogen-doped carbon(N-C)materials have demonstrated exceptional performances in activating peroxymonosulfate(PMS)for environmental remediation.However,accommodating higher nitrogen contents remains challenging in N-C due to the thermodynamic instability of C-N skeleton.In this study,we proposed an innovative epitaxial growth approach to synthesize two-dimensional N-C nanosheets.Leveraging the abundant amino groups supplied by the polymer dots as growing sites,we successfully attained a high nitrogen level and spontaneously introduced abundant structural defects in the carbon framework.The resulting N-C nanosheets exhibited outstanding catalytic activity for the activation of PMS toward selective oxidation of diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate(1,4-DHP)into diethyl2,6-dimethylpyridine-3,5-dicarboxylate,which serves as a valuable intermediate in the synthesis of various pharmaceutical compounds.Comprehensive experimental and characterization investigations verified that the nitrogen sites and defects are the primary active sites for PMS activation and selective oxidation of 1,4-DHP.This work offered an efficient approach for the fabrication of high-nitrogen-loading carbon materials for catalytic oxidation reactions.

Novel Synthesis, Crystal Structure, and Plant-growth Regulation Activity of(1S,4R)-4,7,7-Trimethyl-6-oxabicyclo[3.2.1]octane-1,4-diol

The title compound,（1S,4R）-4,7,7-trimethyl-6-oxabicyclo [3.2.1] octane-1,4-diol（C（10）H（18）O3）, has been synthesized from terpinolene via one-step catalytic synthetic method and structurally characterized by means of HRMS, IR, 1H-NMR, （13）C-NMR and single-crystal X-ray diffraction. The compound crystallizes in trigonal, space group R-3, with a = 27.892（9）, b = 27.892（9）, c = 6.720（2） A, γ = 120°, Z = 18, V = 4527（3） A3, Dc = 1.230 g/cm3, Mr = 186.24, λ（Mo Kα） = 0.71073？, μ = 0.09 mm（-1）, F（000） = 1836, the final R = 0.051 and wR = 0.161. The title compound molecule contained a 6-oxabicyclo[3.2.1]octane skeleton and two hydroxyl groups, which were connected through intermolecular O–H…O hydrogen bonds to generate a two-dimensional network. Especially, the preliminary bioassay showed that the title compound can promote the root growth and shoot elongation of rape（Brassica campestris） at low concentration（0.62570 mmol·L^-1） and inhibit them at high concentration（〉 70 mmol·L^-1）.

Further study on the synthesis of F-containing porphyrins and their catalytic activity on oxidation of cyclohexene

Reaction of tetrakis(p-allyloxyphenyl)porphyrin and perfluoroalkanesulfonyl bromides gives tetrakis(p-polyfluoroalkoxylphenyl)substituted porphyrins.The yields are over 90%.The synthesis of the metal ion complexes of these F-containing porphyrins is also reported.Preliminary results on the study of the catalytic activity of the manganese(Ⅲ)complexes of various fluorinated porphyrins on oxidation of cyclohexene indicate that the introduction of R_F group into porphyrin contributes to the stability of the catalysts.

Synthesis and spectroscopic characterization of cobalt porphyrins and their catalytic activity towards dioxygen reduction

The synthesis and spectroscopic characterization of cobalt(Ⅱ) 5-(4-pyridyl)-10,15,20-triphe- nylporphyrin,cobalt(Ⅱ) 5-(4-N-hexadecylpyridiniumyl)-10,15,20-triphenylporphyrin bromide and cobalt(Ⅱ) 5-(2-aminophenyl)-10,15,20-triphenyl-porphyrin are reported.The corresponding copper and vanadyl derivatives ((TriP)Cu,[(hTriP)Cu]^+Br^- and [(hTriP)VO]^+Br^-) were also studied.Each metalloporphyrin was characterized by UV-visible,ESR and ~1H NMR spectroscopy.These me- talloporphyrins can be firmly adsorbed on the glassy carbon (GC) surface.The catalytic reduction of dioxygen at GC electrodes modified by these catalysts was studied by cyclic voltammetry (CV).The kinetic process of dioxygen reduction at the cobalt porphyrin-modified electrodes was studied with a rotating ring disk electrode.

Studies on the synthesis of amino acids XII.Solid-liquid phase transfer catalytic dicondensation of 1,4-diacety1-2,5-piperazinedione with aldehydes

3,6-Diarylidene-2,5-piperazinediones(2)and 3-alkylidene-6-arylidene-2,5-piperazfnediones (6)were synthesized from diacetyl-2,5-piperazinedione(1)under solid-liquid phase transfer catalytic conditions.2 could be easily convered to a-amino acid by reducing with zinc powder and hydrolyzing with concentrated hydrochloric acid.The effect of different phase transfer catalysts and reaction con- ditions were studied.

Optimizing the Preparation Parameters of Nanocrystalline Zirconia for Catalytic Applications

Nanocrystalline zirconia powder with high surface area and high tetragonal phase percentage is prepared by the precipitation method using ammonium hydroxide as a precipitating agent. The pH of precipitation, preparation temperature and calcinations＇ temperature are optimized.Crystallite size, specific surface area, tetragonal phase percentage and the thermal stability of the prepared samples are identified by diferent characterization tools such as X-ray difraction（XRD）, thermo gravimetric analysis（TGA）, diferential scanning calorimetry（DSC）, BET surface area, scanning electron microscopy（SEM） and transmission electron microscopy（TEM）. The optimum preparation parameters for obtaining nanocrystalline zirconia with high percentage of tetragonal phase and high surface area are pH 9, preparation temperature of 80℃ and calcinations＇ temperature of 400℃. The sample prepared under optimized conditions showed a high specific surface area of 179.2 m2/g, high tetragonal phase percentage of 81% and high catalytic activity（60%） for synthesis of butyl acetate ester.

Catalytic Asymmetric[2,3]-Sigmatropic Rearrangement of Sulfur Ylides Generated from Carbenoids and Allenic 2-Methylphenyl Sulfide

The first investigation on catalytic asymmetric [2,3]-sigmatrop-ic rearrangement of sulfur ylides generated from carbenoids and allenic phenyl sulfide was carried out. Up to 55% ee value was obtained.

Construction of axially chiral compounds via catalytic asymmetric radical reaction

The chemistry of axially chiral compounds has emerged as a subject of increasing interest due to their widespread presence in natural products,bioactive molecules,advanced materials,and chiral ligands/catalysts.On the other hand,catalytic asymmetric radical-based transformations provide a complementary platform for the construction of enantiomerically enriched molecules that are in growing demand in the chemical and pharmaceutical in-dustries.In recent years,considerable research efforts have been devoted to the development of catalytic asymmetric radical reactions for the construction of axially chiral compounds based on the unique reactivity modes of diverse radicals.In this review,we critically illustrate these recent achievements according to different radical precursors and catalytic activation modes.Wherever possible,special emphasis is also placed on the discussion of mechanistic features underlying these works and substrate scopes.This review should be of great interest to the experts in this area,but also serve as a helpful starting point for new researchers in this field.

An efficient chlorination of aromatic compounds using a catalytic amount of iodobenzene

An efficient method was developed for chlorination of aromatic compounds with electron-donating groups using iodobenzene as the catalyst and m-chloroperbenzoic acid as the terminal oxidant in the presence of 4-methylbenzenesulfonic acid in THF at room temperature for 24 h,and a series of the monochlorinated compounds was obtained in good yields.In this protocol,the catalyst iodobenzene was first oxidized into the hypervalent iodine intermediate,which then treated with lithium chloride and finally reacted with aromatic compounds to form the chlorinated compounds.

Palladium-catalyzed asymmetric carbamoyl-carbonylation of alkenes

An unprecedented palladium-catalyzed asymmetric carbamoyl-carbonylation of tethered alkenes with CO and alcohols has been developed.This reaction provided an efficient route to access oxindoles andγ-lactams bearingβ-carbonyl substituted quaternary carbons in good yields with excellent chemo-,regio-and enantioselectivity.Gram-scale synthetic capability and facile transformations of the products to chiral spirooxindole and other functional molecules further illustrated the practicability of this reaction.