The invention relates to a method for the non-stereoselective and also for the stereoselective synthesis of astaxanthin from astacin. For this purpose, a reducing agent is used selected from the group of hydrogen, a secondary alcohol, formic acid and also the salts of formic acid or from a mixture of at least two representatives of the compound classes stated above. The invention further relates to the use of astacin as starting compound for the synthesis of astaxanthin.

An organometallic complex catalyst that makes it possible to obtain a higher yield of a desired product than conventional catalysts in a cross-coupling reaction. The organometallic complex catalyst has a structure represented by formula (1) and is for use in a cross-coupling reaction. In formula (1), M is the coordination center and represents a metal atom such as Pd or an ion thereof. R1, R2, and R3 may be the same or different and are a substituent such as a hydrogen atom. R4, R5, R6, and R7 may be the same or different and are a substituent such as a hydrogen atom. X represents a halogen atom. R8 represents a substituent that has a π bond and 3-20 carbon atoms. With regard to the electron-donating properties of R1-R7 with respect to the coordination center M of the ligand containing R1-R7 that is indicated in formula (2), R1-R7 are arranged in combination such that the TEP value obtained from infrared spectroscopy shifts toward the low frequency side compared to the TEP value of the ligand of formula (2-1).

##STR00001##

A hydrosilylation reaction catalyst prepared from: a catalyst precursor comprising a transition metal compound, excluding platinum, belonging to group 8-10 of the periodic table, e.g., iron acetate, cobalt acetate, nickel acetate, etc.; and a ligand comprising an isocyanide compound such as t-butyl isocyanide. The hydrosilylation reaction catalyst has excellent handling and storage properties. As a result of using this catalyst, a hydrosilylation reaction can be promoted under gentle conditions.

The present invention relates to a catalyst system containing a metathesis catalyst containing at least one N-heterocyclic carbene ligand and at least one phenolic compound and to a process for performing the metathesis on nitrile rubbers for reducing their molecular weight using a metathesis catalyst containing at least one N-heterocyclic carbene ligand (NHC ligand) and at least one phenolic compound.

The present invention provides a novel process for subjecting a diene-based-polymer to a metathesis reaction in a first step and a selective hydrogenation of the carbon-carbon double bonds present in such diene-based polymers in a second step using a ruthenium or osmium based complex catalyst, wherein the diene-based polymer is present in latex form, this means as a suspension of diene-based polymer particles in an aqueous medium.

The present invention is directed to reaction mixtures comprising a water-surfactant mixture, wherein the catalyst comprises a compound with solubilizing groups. This technology improves the solubility of the reaction components in the water-surfactant mixture and thereby, greatly increases the productivity and selectivity of the chemical reaction.

The purification method of an aldehyde compound of the present invention includes a step of neutralizing a reaction solution containing an aldehyde compound by adding water and a base compound to the reaction solution, and a step of distilling the neutralized reaction solution, in which the reaction solution is obtained by reacting a compound represented by the following Formula (a1) or (a2) with hydrogen and carbon monoxide in the presence of a metal compound of groups 8 to 10 and a phosphorus compound, the phosphorus compound is represented by Formula (R.sup.1O).sub.3P, and the base compound is at least one kind selected from among carbonate and hydrogen carbonate of metals of group I on the periodic table and carbonate and hydrogen carbonate of metals of group II on the periodic table. ##STR00001##

A hydrosilylation reaction catalyst prepared from: a catalyst precursor comprising a transition metal compound, excluding platinum, belonging to group 8-10 of the periodic table, e.g., iron acetate, cobalt acetate, nickel acetate, etc.; and a ligand comprising a carbine compound such as 1,3-dimesitylimidazol-2-ylidene, etc. The hydrosilylation reaction catalyst has excellent handling and storage properties. As a result of using this catalyst, a hydrosilylation reaction can be promoted under gentle conditions.

The current invention describes new metathesis catalysts, a method for their preparation and their use in metathesis reactions.

The invention relates to a method for converting a precatalyst complex to an active catalyst complex, wherein the precatalyst complex and the active catalyst complex comprise a ruthenium atom and an optically active ligand that is insoluble in water, and the active catalyst complex furthermore comprises a monohydride and a water molecule. The method comprises the steps of providing water as an activation solvent system with a pH value equal or below 2, and solving said precatalyst complex, an acid, and hydrogen therein. The invention further relates to a method for manufacturing a catalyst composition, a method for hydrogenating a substrate molecule and a reaction mixture.