Abstract:
The present invention relates to a method for obtaining a high yield of sugar alcohols containing five to six carbon atoms from cellulose-containing materials. In a first step the starting materials (for example microcrystalline cellulose, alpha-cellulose, wood and cellulose-containing residues, such as sugar cane bagasse or wood shavings) and an acid are brought into close contact with the substrates by a impregnation carried out in the liquid or gaseous phase. In addition, in a second step the starting materials impregnated with acid and preferably dried are brought into contact by the action of mechanical energy, such that the cellulose-containing materials are degraded into water-soluble products. Subsequently, in a third step, sugar alcohols having five to six carbon atoms are obtained in a high yield and in high selectivity from the water-soluble products in aqueous solution by hydrolytic hydrogenation by means of a metal-containing catalyst under hydrogen pressure.
Abstract:
The present invention relates to methods for the preparation of solid-supported heterogeneous organic catalyst covalently bound to textile materials, preferably via photochemical immobilization. More specifically, the present invention relates to the organocatalysis and recognition process by using the textile-supported chiral molecules.
Abstract:
The present invention refers to highly sinter-stable metal nanoparticles supported on mesoporous graphitic spheres, the so obtained metal-loaded mesoporous graphitic particles, processes for their preparation and the use thereof as catalysts, in particular for high temperature reactions in reducing atmosphere and cathode side oxygen reduction reaction (ORR) in PEM fuel cells.
Abstract:
A series of mono, bi and tricarbocyclic compounds, most of which have olefinic unsaturation in the ring, which may or may not have substituents thereon. While the bi and tricyclic rings may be unsubstituted, these compounds which have olefinic unsaturation, particularly multiple olefinic unsaturation, are polymerizable and copolymerizable in known polymerization systems. They are particularly good crosslinking agents. These compounds are further useful in the sense that they can be cleaved oxidatively, to corresponding carboxylic acids, aldehydes and/or alcohols which have known utility in the plasticizer and detergent arts. The compounds which do not have olefinic unsaturation can also be oxidatively cleaved to produce oxygenated, e.g., acid, alcohol or aldehyde, compounds having known utility.
Abstract:
Allylidene phosphoranes are prepared by a new process comprising reacting dialkyl aluminum alkylidene amides or bis(N-dialkyl aluminum-imino)alkanes which are obtainable from saturated aliphatic nitriles or dinitriles and dialkyl aluminum hydrides with alkylidene phosphoranes R3CH PR34. The allylidene phosphoranes are useful as intermediate products in the synthesis of 1,3-dienes which include insect attracting substances and flavoring agents, and in the synthesis of 1,5-dienes such as squalene.
Abstract:
MIXED OLIGOMERS ARE PREPARED BY REACTING 1,3-DIENES WITH ETHYLENE OR ETHYLENICALLY UNSATURAED COMPOUNDS IN THE PRESENCE OF A CYCLOOLEFIN-COBALT COMPLEX CATALYST.
Abstract:
ZERO-VALENT COMPLEXES OF GROUP VIII METALS, OXYGEN AND AN ELECTRON DONOR SUCH AS, FOR EXAMPLE, A GROUP V METAL TRIVALENT COMPOUND, E.G., TRIPHENYL PHOSPHINE; PRODUCTION OF SUCH ZERO-VALENT COMPLEXES BY REACTING A ZEROVALENT COMPOUND OF A GROUP VIII METAL AND AN ELECTRON DONOR WITH MOLECULAR OXYGEN PREFERABLY AT A TEMPERATURE OF ABOUT - 100 TO ABOUT 75*C. THESE COMPLEXES CAN BE USED AS OXYGEN TRANSFER AGENTS AND FOR THE PREPARATION OF FINELY DIVIDED, HIGHLY ACTIVE METALS OF SUB-GROUP VIII OF THE PERIODIC TABLE.