摘要:
The present invention relates in a first aspect to a process for hydrogenation of ketones having at least a carbon-carbon double bond in the y,8-position to the keto group by hydrogen in the presence of at least one chiral iridium complex of formula (I), where R1 represents a group of formula (II) or (III) or (IV). It has been shown that this process leads to a strong increase in preferential formation of a single isomer. The process is particularly suitable for the hydrogenation of y,8-unsaturated ketones which can be used as flavours and fragrances or for the preparation of vitamin E and its derivatives or of flavours and fragrances.
摘要:
The invention relates to a method of use of certain derivatives of formula (I) in the form of any one of its stereoisomers or a mixture thereof, and wherein R1 represents a hydrogen atom, a C1-4 alkyl or alkenyl group, or a (CHR)2OH group, each R being a hydrogen atom or a methyl group; R2 represents a hydrogen atom or a methyl, ethyl or n-propyl group; and R3 represents a hydrogen atom or a methyl group, as perfuming ingredients. The present invention concerns also certain compounds and compositions or articles containing such compounds.
摘要:
A method for surface treating a carbon-containing material in which carbon-containing material is reacted with decomposing ozone in a reactor (e.g., a hollow tube reactor), wherein a concentration of ozone is maintained throughout the reactor by appropriate selection of at least processing temperature, gas stream flow rate, reactor dimensions, ozone concentration entering the reactor, and position of one or more ozone inlets (ports) in the reactor, wherein the method produces a surface-oxidized carbon or carbon-containing material, preferably having a surface atomic oxygen content of at least 15%. The resulting surface-oxidized carbon material and solid composites made therefrom are also described.
摘要:
Cyclic alkynes (e.g., cyclooctynes such as dibenzocyclooctynes) can be photochemically generated from cyclopropenones as disclosed herein. The cyclic alkynes can be reacted (e.g., in situ) with materials having alkyne-reactive groups (e.g., azide groups in a “click” reaction). In preferred embodiments, the generation and reaction of the cyclic alkyne can proceed in the absence of a catalyst (e.g., Cu(I)). These reactions can be useful, for example, for the selective labeling of living cells that are metabolically modified with azido-containing surface monosaccharides, or for light-directed surface patterning.
摘要:
Alkoxy[13C]methyl phenyl sulfone is a precursor to the production of Lithium (E)-β-Alkoxy[1,2,3-13C3]acrylate and thence Alkoxy (E)-β-Alkoxy[1,2,3-13C3]acrylate. Alkoxy (E)-β-Alkoxy[1,2,3-13C3]acrylate can then serve as a precursor for the production of a number of other isotopically labeled compounds. Similar chemistry using Alkoxy[14C]methyl phenyl sulfone as the precursor can yield 14C labeled compounds. High purity precursors ensure that the new compounds are also highly pure.
摘要:
Described herein are macromolecules modified with electrophilic groups and methods of making and using thereof. The preparation of a thiol-reactive, electrophililic derivative of HA in order to prepare “crosslinker-free” hydrogels are described as well as compounds and methods that are capable of coupling two or more molecules, such as macromolecules, under mild conditions. Specifically disclosed is the introduction of reactive bromo- and iodoacetate functionalities at the hydroxyl groups that are abundantly present on the HA polymer. The “crosslinker-free” hydrogels described have numerous applications including, but not limited to, drug delivery, small molecule delivery, wound healing, burn injury healing, tissue regeneration/engineering, cell culturing, and bio-artificial materials.
摘要:
The present invention relates to compounds of general formula R-Z1-Z2-Z3-R (I), wherein R, R1 and Z1 to Z3 are defined as in claim 1, the tautomers, the diastereomers, the enantiomers, the mixtures thereof and the salts thereof, particularly the physiologically acceptable salts thereof with inorganic or organic acids or bases, which have valuable pharmacological properties, particularly CGRP-antagonistic properties, pharmaceutical compositions containing these compounds, their use and processes for preparing them.
摘要:
The present invention is directed to novel acyloins, their derivatives, methods for their production and their use for the production of novel epothilones and their derivatives. In addition, the invention is directed to the building blocks for epothilone synthesis, methods for their production and the use of synthetic building blocks for the production of epothilones and their derivatives.
摘要:
The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative.The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative.The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: ##STR1##
摘要:
A process for preparing an aldehyde or ketone comprising reacting a primary or secondary alcohol with oxygen in the presence of a base, a catalytic amount of a copper salt and a suitable lignad under anhydrous conditions.