摘要:
Branched saturated dinitrile byproducts, e.g. 2-methylglutaronitrile, 2-ethylsuccinonitrile and mixtures thereof, are converted into useful ethylenic nitriles by dehydrocyanating same, in vapor phase, in the presence of an at least partially acidified cation exchange substrate, notably a molecular sieve, clay, acid oxide or lamellar phosphate.
摘要:
Hydroxyaromatic aldehydes are prepared by oxidation of a corresponding mandelic derivative carried out in a basic medium and in the presence of a catalytic system containing at least two metal elements.
摘要:
The invention relates to novel compounds with a guanidine structure, and more particularly nontoxic compounds with a silylated guanidine structure.
摘要:
A silicone composition is described that includes components having SiH/SiOH group and that can be polymerized/cross-linked by a dehydrocondensation reaction in the presence of a catalyst such as an iron-based complex or salt, requiring a low activation temperature.
摘要:
Hydroxyaromatic aldehydes are prepared by oxidation of a corresponding mandelic derivative carried out in a basic medium and in the presence of a catalytic system containing at least two metal elements.
摘要:
The invention relates to novel compounds with a guanidine structure, and more particularly nontoxic compounds with a silylated guanidine structure.
摘要:
The present invention relates to an organopolysiloxane composition that can be vulcanized at room temperature into an elastomer that is crosslinked by polycondensation and that does not contain alkyltin-based catalysts and also to novel organopolysiloxane polycondensation catalysts.
摘要:
The present invention relates to an organopolysiloxane composition that can be vulcanized at room temperature into an elastomer that is crosslinked by polycondensation and that does not contain alkyltin-based catalysts and also to novel organopolysiloxane polycondensation catalysts.
摘要:
The invention relates to a method for preparing carbene by means of deprotonation of a precursor salt using a strong base. A purpose of the invention is to enhance the synthesis of carbenes, i.e. to simplify same, to make said synthesis more economical and to obtain a liquid or solid, stable and pure form constituting a catalytic system that is easy to store and use and that has a higher efficiency, higher yield and higher selectivity than carbene catalysts of the prior art. In order to do so, the method comprises deprotonation in a solvent including an alcohol. The invention also relates to an alcohol-containing solution and carbene, and to a solid that can be obtained from the solution, e.g. by means of sublimation.
摘要:
The invention relates to a silicone composition comprising components bearing ≡SiH/≡SiOH groups, which can be polymerised/cross-linked by means of a dehydrogenative condensation reaction in the presence of a carbene-type catalyst in solution.