Peng-cheng Wang

β-Cyclodextrin coated Fe3O4 nanoparticles: a simple preparation and application for selective oxidation of alcohols in water

A magnetically separable catalyst was synthesized via a carbodiimide activation process with β-cyclodextrin functionalized by core-shell nanoparticles (Fe3O4/SiO2/CM-β-CD). The catalyst presented high activity for selective oxidation of various alcohols with NaOCl as oxidant and water only as the solvent. A substrate-selective and transition metal-free process was achieved with easy separation of the catalyst.

Study on the one-pot oxidative esterification of glycerol with MOF supported polyoxometalates as catalyst

In this work, glycerol was treated under green and mild conditions (water solvent, H2O2 oxidant, 40 °C) in an attempt to utilise its additional value. With a metal organic framework (MOF) supported polyoxometallate (POM) as a catalyst, esters were generated as one of the major products which could be useful for various industrial applications. The selectivity of esters formation reached 34.5% in this one-pot oxidative esterification process. Benefiting from the pore limitation effect of the MOF, diffusion was restricted and the original products could be further transformed into esters with the existence of the POM. No other reagents were needed during this process, and all of the intermediates were produced from glycerol itself. The oxidative esterification reaction was studied in detail including the role of the MOF, the influence of pH and the POM type, the mechanism and so on. It was concluded that the POM served as the active site for this oxidative esterification process and H2O2 provided weak acidity in addition to the source of oxygen. Too stronger acidity and oxidizability were unfavourable to the generation of esters. Also, the catalysts could be recovered after reaction, exhibiting good stability and reusability.

Preparation of heteropoly acid based amphiphilic salts supported by nano oxides and their catalytic performance in the nitration of aromatics

A series of Keggin heteropoly acid anion based amphiphilic salts supported by nano oxides were synthesized and used as catalysts in the nitration of aromatic compounds with HNO3. The reaction conditions in the nitration of toluene were optimized and both 92.6% conversion and good para selectivity (ortho:para = 1.09) were obtained.

Preparation, characterization, and catalytic performance of a novel TEMPO-functionalized acid magnetic catalyst

A novel magnetically recoverable catalyst in which magnetic nanoparticles were coated by polymeric multilayers containing 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)- and sulfonic-acid-functionalized imidazolium ionic liquids was prepared, characterized, and used in selective oxidation of benzyl alcohol. Due to the coexistence of TEMPO and the magnetic core, both good catalytic performance and facilitated separation were achieved for the reaction process. Different from the general TEMPO/NaNO2 system, addition of conventional acid was avoided due to the acid property of the catalyst.Graphical abstract.

A Novel and Efficient Synthesis of Hexanitrostilbene by N-Hydroxyphthalimide/FeCl2-Catalyzed Aerobic Dehydrogenation of Hexanitrobibenzyl

A novel and effective catalytic system containing N-hydroxyphthalimide (NHPI) and FeCl2 is described for the preparation of hexanitrostilbene (HNS) by the dehydrogenation of hexanitrobibenzyl (HNBB) under an oxygen atmosphere. The reaction conditions, such as reaction time, and the amount of NHPI were discussed. The efficient and more environmentally friendly method proved to be a better selection when compared to other previous methods, such as Shipp and Kaplans method [1].

AN INEXPENSIVE AND CONVENIENT PROCEDURE FOR CHLOROMETHYLATION OF AROMATIC HYDROCARBONS BY PHASE TRANSFER CATALYSIS IN AQUEOUS MEDIA

Reaction of aromatic hydrocarbons catalyzed by a novel catalytic system consisting of zinc chloride, acetic acid, sulfuric acid and PEG-800 in aqueous media under PTC conditions results in chloromethylation in good to excellent yield.