Abstract:
PROBLEM TO BE SOLVED: To provide a method enabling to manufacture optically active menthol, desirably L-menthol and racemic menthol in a variety of quantity according to the demand without changing an enantioselective catalyst system and/or without excessively obtaining one of products for need of changing a reaction condition.SOLUTION: A method for producing menthol includes a process (a. 1) of obtaining a citronellal by catalyst-hydrogenation of a neral and/or a geranial, a process (b. 1) of obtaining an isopulegol by cyclizing citronellal in the presence of an acid catalyst, a process (c. 1) of purifying the isopulegol by crystallization, and a process (d. 1) of producing menthol by catalyst-hydrogenation of the isopulegol.
Abstract:
The invention relates to a particularly economic, complete method for producing menthol, especially for the production of optically active, essentially enantiomerically and diastereomerically pure L-menthol and of racemic menthol starting from the commercially accessible, inexpensive parent material citral. The method comprises the following steps: a.1 ) catalytic hydrogenation of neral and/or geranial to form citronellal, b.1 ) cyclisation of citronellal to form isopulegol in the presence of an acidic catalyst, c.1 ) purification of isopulegol by crystallisation and d.1 ) catalytic hydrogenation of isopulegol to form menthol.
Abstract:
The present invention relates to a method for reacting compounds, comprising at least one carbon-carbon or carbon-heteroatom double bond, by 1,2-addition in the presence of a catalyst, comprising at least one transition metal complex having at least two ligands, which each have a pnicogen atom-containing group and at least one functional group enable to form intermolecular, non-covalent bonds, in the presence of a halogenated solvent, which has at least one heteroatom different from halogen. The present invention further relates to a method for producing chiral compounds in the presence of the above-described catalysts and solvents, and to the use of these catalysts in the presence of such solvents.
Abstract:
The present invention relates to catalysts comprising at least one metal complex with at least two ligands which each have at least one pnicogen atom and at least one functional group capable of forming intermolecular, ionic interactions, wherein the complex has ligands which are dimerized via intermolecular ionic interactions, and also processes for reacting compounds which contain at least one carbon-carbon or carbon-heteroatom double bond by 1,2-addition in the presence of the catalysts of the invention.
Abstract:
The invention relates to a method for producing formic acid by hydrogenation of carbon dioxide in the presence of a catalyst which contains an element of the 8th, 9th or 10th group of the periodic system, a tertiary amine and a polar solvent, at a pressure of 0.2 to 30 MPa abs and a temperature of 20 to 200°C, thereby producing two liquid phases, and separation of the two liquid phases. The liquid phase (B) enriched by the tertiary amine is returned to the hydrogenation reactor and the formic acid/amine addition product from the liquid phase (A) enriched by the formic acid/amine addition product and the polar solvent is thermally separated into free formic acid and free tertiary amine in a distillation unit and the tertiary amine released during separation and the polar solvent are returned to the hydrogenation reactor.
Abstract:
Método para la producción de alcoholes de C9, en el cual a) se proporciona una corriente de hidrocarburo de C4 que contiene buteno y butano; b) se somete la corriente de hidrocarburo de C4 a una oligomerización en un catalizador de oligomerización de olefina y la mezcla de reacción obtenida se separa, en cuyo caso se obtienen una corriente que 5 contiene octenos y una corriente de hidrocarburo de C4 mermada en buteno; c) se somete la corriente de hidrocarburo de C4 mermada en buteno a un reformado con vapor o a una oxidación parcial, en cuyo caso se obtienen monóxido de carbono e hidrógeno; d) se hidroformila la corriente que contiene octenos en presencia de un catalizador de hidroformilación con monóxido de carbono e hidrógeno para producir aldehídos de C9, en cuyo caso el monóxido de carbono empleado y el hidrógeno empleado provienen en más de 80% del paso c); y e) se hidrogenan catalíticamente los aldehídos de C9 con hidrógeno, en cuyo caso el hidrógeno empleado en el paso e) proviene en más de 80% del paso c).
Abstract:
A catalytic process for preparing an α,β-ethylenically unsaturated carboxylic acid salt from an alkene, carbon dioxide and an alkoxide having a secondary or tertiary carbon atom directly bound to a [O-] group is described. The alcohol byproduct is distilled off after an intermediate phase separation. This provides pure α,β-ethylenically unsaturated carboxylic acid salt at minimum effort.
Abstract:
La invención se refiere a un procedimiento para la hidrogenación de un éster con hidrógeno molecular para dar los alcoholes correspondientes en presencia de un complejo de rutenio (I), en el que dicho complejo contiene un ligando tridentado L de fórmula general (II), n y m son independientemente 0 ó 1, y las líneas dobles continuas-discontinuas representan un enlace simple o un enlace doble, con la condición de que si n = 1, ambas líneas dobles continuas-discontinuas representan un enlace simple y m es 1, y si n = 0, una línea doble continua-discontinua representa un enlace simple y la otra línea doble continua-discontinua representa un enlace doble, y si hay un enlace doble en el lado que da al anillo de fenilo, m = 1, si hay un enlace doble en el lado que da al anillo de piridilo, m = 0, o ambas líneas dobles continuas-discontinuas representan un enlace simple y m es 1. (Traducción automática con Google Translate, sin valor legal)