Abstract:
This invention relates to a process for catalytically hydrogenating a hydrogenatable precursor in contact with a hydrogen-containing gas and a hydrogenation catalyst comprising one or more active hydrogenation catalyst components on a support comprising titanium dioxide in the rutile crystalline phase to produce 1,4-butanediol and, optionally, gamma-butyrolactone and/or tetrahydrofuran.
Abstract:
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Menthol durch katalytische Hydrierung von Verbindungen, die das Kohlenstoffgerüst des Menthans mit wenigstens einer Doppelbindung besitzen und in 3-Stellung durch Sauerstoff substituiert sind und/oder katalytische Umlagerung von Stereoisomeren des Menthols in Gegenwart von Wasserstoff und dotierten Nickel-Katalysatoren.
Abstract:
Die vorliegende Erfindung betrifft ein Verfahren zur Hydrierung mindestens einer organischen Verbindung durch Inkontaktbringen der mindestens einen organischen Verbindung mit einem Wasserstoff enthaltenden Gas in Gegenwart eines Katalysators, der als Aktiv- metall Ruthenium alleine oder zusammen mit mindestens einem weiteren Metall der I., VII. oder VIII. Nebengruppe des Periodensystems, aufgebracht auf ein Trägermaterial auf Basis von amorphem Siliziumdioxid, umfasst und der erhältlich ist durch: i) ein oder mehrfaches Behandeln eines Trägermaterials auf Basis von amorphem Siliziumdioxid mit einer halogenfreien wässrigen Lösung einer niedermolekularen Rutheniumverbindung und anschliessendes Trocknen des behandelten Trägermaterials bei einer Temperatur unterhalb 200 °C, ii) Reduktion des in i) erhaltenen Feststoffs mit Wasserstoff bei einer Temperatur im Bereich von 100 bis 350 °C, wobei man Schritt ii) unmittelbar im Anschluss an Schritt i) durchführt.
Abstract:
The invention relates to a supported catalyst consisting of metal of the platinum group. Said catalyst can be obtained by means of controlled electroless deposition of at least one metal of the platinum group from a precipitation solution containing i) at least one homogeneously dissolved compound consisting of metal of the platinum group, ii) a reducing agent, and iii) at least one collagen selected from iospoly acids and heteropoly acids of niobium, tantalum, molybdenum, tungsten and vanadium or the salts of the same. The invention also relates to a method for hydrogenating inorganic or organic compounds using the catalyst which is produced by means of controlled electroless deposition, especially for the direct synthesis of hydrogen peroxide.
Abstract:
Production of unsaturated ketones by the aldol condensation of ketones such as acetone or methyl ethyl ketone by contacting the ketone in the vapour phase with a particulate catalyst comprising at least one basic alkali metal compound supported on an inert substrate at a temperature above 175 DEG C. The product ketones may be hydrogenated to form saturated ketones or alcohols.
Abstract:
In a method of performing a chemical reaction using a Lewis acid, after the reaction is complete, the Lewis acid is extracted from the reaction product in the form of an aqueous solution, followed by drying of the aqueous solution of the Lewis acid. The dried Lewis acid can be reused in a further similar reaction. The method can be repeated several times, using the same batch of Lewis acid, without the activity and specificity of the Lewis acid being significantly affected. The invention has been used to good effect in the ene reaction of isopulegol from citronellal, the Diels-Alder reaction of myrcene and 3-methyl-3-penten-2-one and the rearrangement reaction of alpha -pinene oxide to campholenic aldehyde using zinc bromide as a Lewis acid catalyst. The invention can thus provide an environmentally acceptable and efficient method for using Lewis acids in industrial processes.
Abstract:
In the proposed process for producing 1,4 butane diol, 2,5 dihydrofurane is reacted in a single step in the presence of water and hydrogen at a temperature of 20 to 300 DEG C and a pressure of 1 to 300 bar with the aid of a hydrogenating catalyst.
Abstract:
Described are racemic optically active phosphorus compounds of formula (I), in which R is a hydroxy or protected hydroxy group, R is a hydroxy or protected hydroxy group or a lower alkoxy group and R is a lower alkyl, cycloalkyl or aryl group or, together with the phosphorus atom, a group of formula (a). The compounds of formula (I) act, in the form of complexes with a group VIII metal, as catalysts for asymmetric-hydrogenation reactions and enantiomer-selective hydrogen-displacement reactions in prochiral allylic systems.
Abstract:
New racemic, optically active phosphorous compounds have the formula (I), in which R stands for lower alkyl, lower alkoxy or a protected hydroxy group; R stands for a 5-membered heteroaromatic compound; R stands for lower alkyl or lower alkoxy and n equals 0, 1 or 2. In the form of complexes with a group VIII metal, the compounds having the formula (I) are useful as catalysts for asymmetrical hydrogenations and for enantioselective hydrogen shifts in prochiral allylic systems.
Abstract translation:新的外消旋的光学活性磷化合物具有式(I),其中R代表低级烷基,低级烷氧基或被保护的羟基; R 1代表5元杂芳族化合物; R 2代表低级烷基或低级烷氧基,n等于0,1或2.以与Ⅷ族金属的络合物的形式,具有式(I)的化合物可用作不对称氢化的催化剂和对映选择性氢 前手性烯丙基体系的转变。