Abstract:
Lactones are prepared by catalytic carbonylation of oxiranes using a catalyst system comprising a) at least one cobalt compound as component A and b) at least one metal compound of the formula (I) as component B, MXxRn-x (I) where M is an alkaline earth metal or a metal of group 3, 4 or preferably 12 or 13 of the Periodic Table of the Elements, R is hydrogen or a hydrocarbon radical which may be substituted on the carbon atoms other than the carbon atom bound to M, X is an anion, n is a number corresponding to the valence of M and x is in the range from 0 to n, with n and x being selected so that the compound is uncharged, as catalyst.
Abstract:
A system which is suitable as a catalyst for the hydrocyanation of olefinically unsaturated compounds and comprises a) Ni(0) b) a compound which complexes Ni(0) as a ligand and contains trivalent phosphorus, c) a Lewis acid and d) a compound of the formula M Rn where M: Al or Ti R: identical or different monovalent alkoxy radicals, in which case a plurality of alkoxy radicals may be bonded together, and additionally, in the case that M=Al, R may be identical or different monovalent alkyl radicals, in which case a plurality of alkyl radicals may be bonded together or one or more alkyl radicals may be bonded to one or more of the abovementioned alkoxy radicals, n: valency of M, and processes for hydrocyanating an olefinically unsaturated compound in the presence of such a system.
Abstract:
The invention relates to phosphinites I of formulae (1) or (2), in which R1, R2, R5, R6, R7, R8, R9 independently represent hydrogen, an alkyl or alkylene group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms; R3 is H or methyl; R4 is i-propyl or t-butyl; X is F, Cl or CF3 and n is 1 or 2.
Abstract:
Lactones are prepared by the catalytic carbonylation of oxiranes using a catalyst system comprising a) at least one carbonylation catalyst A comprising uncharged or anionic transition metal complexes of metals of groups 5 to 11 of the Periodic Table, b) at least one metal compound B of the formula (I) MXxRn-x (I) where M is an element of group 2, 3, 4, 12, 13, R is hydrogen or a hydrocarbon radical which may be substituted on the carbon atoms other than on the carbon atom bound to M, X is an anion, n is a number corresponding to the valence of M, x is in the range from 0 to n, and c) at least one organic, chiral compound C which has fewer than four coordination sites.
Abstract:
The invention relates to a process for preparing polyhydroxyalkanoates by polymerization of lactones of the general formula I, where the substituents and the index n have the meanings given in the description, in the presence of at least one catalyst of the formula (II) LIMaXam, where the substituents and indices have the meanings given in the description. The invention further relates to poly-3-hydroxybutyrates which have a novel property profile and are obtainable for the first time by means of this process, and also biodegradable polyester mixtures based on these poly-3-hydroxybutyrates.
Abstract:
Phosphonites I of the formula 1 or 2 where R1, R2 are each, independently of one another, hydrogen, an alkyl or alkylene group having from 1 to 8 carbon atoms or an alkoxy group having from 1 to 8 carbon atoms, with the proviso that R1 and R2 are not simultaneously H, R3 is H or methyl, R4 is t-butyl, R5, R6, R7, R8, R9 are each, independently of one another, H or an alkyl or alkylene group having from 1 to 8 carbon atoms.
Abstract:
Disclosed is a method for the oligomerization of olefins, wherein an olefin is brought into contact with a catalyst system that is obtained from a chromium source, a cycloalkylalkyl-substituted triazacyclohexane, especially a 1,3,5-tris-(cycloalkylalkyl)-1,3,5-triazacyclohexane and an activator such as an alkyl aluminum compound or an alkylalumoxane.
Abstract:
Phosphinites I of the formula 1, 2 or 3 where R1, R2, R4 are each, independently of one another, hydrogen, an alkyl or alkylene group having from 1 to 8 carbon atoms or an alkoxy group having from 1 to 8 carbon atoms, with the proviso that at least one of the groups R1, R2, R4 is not H, R3 is H or methyl X is F, Cl or CF3 n is 0, 1 or 2 can be used as catalysts.
Abstract:
A fin (1) for a windsurf board is constructed from fibers (5) which have a preferred fiber direction with the majority of the fibers lying in this direction, the preferred direction extending at an acute angle (a) to the longitudinal axis (4) of the profile of the fin blade (2). This allows the fin to distort and to change the properties of its profile in a defined manner when loaded.