Consecutive Reaction of Bis[2,2,2-trifluoroethyl]phosphite.Onepot Synthesis of Substituted 3-Cyano-β,γ-unsaturated Nitriles with Exclusive or Predominant E-Selectivity

The consecutive reaction of bis [2,2,2-trifluoroethyl ] phosphite and its application to the one-pot synthesis of 3-cyano-β,γ-un-saturated nitriles with exclusive or predominant E-selectivity (E:Z = 100-85:0-15) and excellent yields (94%-99%) are described.

MATHEMATICAL MODEL FOR THERMOKINETICS OF IRREVERSIBLE CONSECUTIVE FIRST ORDER REACTIONS

The mathematical model for the thermokinetics of irreversible consecutive first order reactions has been suggested,which was used for the calculation of rate constants and molar enthalpies of the two consecutive steps.And its validity has been verified by the ex- perimental results.

Selectivity modulation in the consecutive hydrogenation of benzaldehyde via functionalization of carbon nanotubes

Hydrogenation of benzaldehyde is a typical consecutive reaction, since the intermediate benzyl alcohol is apt to be further hydrogenated. Here we demonstrate that the selectivity of benzyl alcohol can be tuned via functionalization of carbon nanotubes （CNTs）, which are used as the support of Pd. With the original CNTs, the selectivity of benzyl alcohol is 88% at a 100% conversion of benzaldehyde. With introduction of oxygen-containing groups onto CNTs, it drops to 27%. In contrast, doping CNTs with N atoms, the selectivity reaches 96% under the same reaction conditions. The kinetic study shows that hydrogenation of benzyl alcohol is significantly suppressed, which can be attributed to weakened adsorption of benzyl alcohol. This is most likely related to the modified electronic structure of Pd species via interaction with functionalized CNTs, as shown by XPS characterization.

A “Green” Cyclohexanone Oxidation Route Catalyzed by Hollow Titanium Silicate Zeolite for Preparing ε-Caprolactone,6-Hydroxyhexanoic Acid and Adipic Acid

Hollow titanium silicalite （HTS） molecular sieve has been synthesized, and information on its structure, physico- chemical characterization, as well as surface property was investigated by a host of analytical methods, such as XRF, XRD, low-temperature N2 adsorption/desorption, TEM, FT-IR, UV-Vis, 29Si MAS NIVIR, and XPS techniques. The characterization results suggest that HTS zeolite has a special hollow crystal structure and its mesopore volume is larger than that of TS-1 zeolite. The titanium species in this zeolite are composed of the framework tetrahedral Ti （IV） ions and extra-framework octahedral Ti （IV） ions, which tend to disperse into its bulk phase. This zeolite material also has been applied to catalyze the cyclohexanone oxidation process, and the products are not completely consistent with those results obtained by using TS-1 zeolite, which might be caused by their difference in pore structure and pore volume, especially the mesopore volume. Cy- clohexanone oxidation catalyzed by HTS zeolite is a representative consecutive reaction, the main target products of which are e-caprolactone, 6-hydroxyhexanoic acid and adipic acid. The effect of H202/cyclohexanone mole ratio on the cyclohexa- none conversion, the total target product selectivity, the distribution of three target products selectivity and their variations along with reaction time is also researched and analyzed, which indicate that HTS zeolite shows a high performance for the Baeyer-Villiger reaction of cyclohexanone and catalytic oxidation of 6-hydroxyhexanoic acid under mild conditions, and the quantity of active surface titanium species as well as the pore structure and mesopore volume controlling the mass diffusion rate are the key factors determining the catalytic activity of HTS zeolite and product selectivity.

Microcalorimetric Investigation on the Kinetics of the Oxidation of Ascorbic Acid with Hydrogen Peroxide

Based on the thermokinetic theory, a novel thermokinetic research methodself-function regression method, which could be used to determine the kinetic parameters k1, k2 and k-1 of the complex reaction: B+ , ,was proposed in this paper. The kinetics of the reaction of ascorbic acid (H2A) with hydrogen peroxide was investigated at pH=57 and T=298.15 K, and the kinetic parameters k1, k 2 and k-1 were obtained with this method. The kinetics of the reaction was investigated in detail. The kinetic parameters of the oxidation of ascorbic monoanion (HA-) and ascorbic dianion (A2-) with hydrogen peroxide were 3.33×10-3 s-1and 25.48 s-1 at 298.15 K, respectively. The molar enthalpy change for the reaction was -554.64 kJ·mol-1 in phosphate buffer solution at pH 7 and at 298.15 K.