摘要:
Process for cross-coupling aromatic boron compounds with aromatic halogen compounds or perfluoroalkylsulfonates.In a process for preparing polycyclic aromatic compounds by cross-coupling aromatic boron compounds with aromatic halogen compounds or perfluoroalkylsulfonates under palladium catalysis in the presence of at least one water-soluble complex ligand, the reaction medium comprises an aqueous and an organic phase and the palladium is added in the form of a palladium compound soluble in the organic phase.Polycyclic aromatic compounds can thus be prepared economically and in very good yields and simultaneously very high purity, in particular without contamination by the complexing ligands.
摘要:
A process for preparing polycyclic aromatic compounds by cross-coupling aromatic boron compounds with aromatic halogen compounds or perfluoroalkylsulfonates in the presence of metallic palladium as catalyst comprises adding to the reaction a) at least one water-soluble complexing ligand and b) sufficient water for the reaction mixture to form an aqueous phase. The reaction of the invention proceeds chemoselectively so that even electrophilic groups such as esters or nitriles do not have an adverse effect on the course of the reaction. The use according to the invention of a water-soluble complexing ligand in an aqueous phase enables polycyclic aromatic compounds to be prepared in very good yields and at the same time very high purity, in particular without contamination by the complexing ligands.
摘要:
Compounds of the formula (I) in which Q1 and Q2 are each OH or form a trimeric boric anhydride, Z is CHO, CH2Y, X or a protected aldehyde group, and X is CN, COOH, COCl, CONH2 or C(OR)3, and Y is OH or NH2, and Z is in the o-, m- or p-position to the boronic acid radical, are prepared by a) reacting a compound of the formula (II) with Mg in the presence of an anthracene compound and, if desired, a transition-metal halide and, if desired, an Mg halide or in the presence of a transition-metal halide and, if desired, an Mg halide, to give the corresponding arylmagnesium chloride, b) reacting the latter with a borate of the formula B(OR′)3 and hydrolyzing the product, with removal of the aldehyde protecting group, c) and, if desired, oxidizing or reducing the free aldehyde group.
摘要:
The invention relates to a process for the preparation of 4-(4′-chlorobiphenyl-4-yl)-4-keto-2-methylenebutyric acid of the formula (I) by Friedel-Crafts acylation of 4-chlorbiphenly with itaconic anhydride, which comprises carrying out the Friedel-Crafts acylation in aromatic solvents at a temperature from −20 to +80° C.
摘要:
A plug-in system for trailer vehicles provided with an automatic coupling system of the supply lines, including a plug (1) supporting the line contacts (1a) and a socket (2). The plug (1) has guide elements (4) that actively engage when approaching the guide elements (5) of the socket (2). The centering of a plug system for an automatic coupling system of supply lines on an articulated train is achieved by the guide elements (4) include a main guide pin (6) and at least one centering pin (7a, 7b) arranged at a distance therefrom. At least the centering pin (7a, 7b) and/or the associated guide element (5, 9) is elastic in the radial direction.
摘要:
2-, 3- or 4-arylpyridines are prepared by reacting a halopyridine with an aryl Grignard compound, where the halogen is chlorine or bromine, in the presence of a palladium catalyst of the formula (IV)
摘要:
Compounds of the formula (I) are prepared by reacting a compound of the formula (V) with a compound of the formula (X) and hydrolyzing the product; or converting the compound of the formula (V) into the hydrazide, and cyclizing and hydrolyzing the latter to give the oxadiazole. para-Oxadiazolylphenylboronic acids are valuable precursors for active ingredients.
摘要:
The invention relates to a method for producing [1,1′:4′,1″]-terphenyl compounds of the formula which comprises reacting a metal aryl of the formula with a boric ester at −80 to 40° C. in the presence of an inert solvent, converting the reaction product by hydrolysis into a boronic acid of the formula reacting the boronic acid, a boronic anhydride obtainable from boronic acid by elimination of water, or a mixture of boronic acid and boronic anhydride, with an alcohol, and reacting the boronic ester formed thereby with a biphenyl compound of the formula at 40 to 180° C. in the presence of a catalyst, of an acid-binding agent and of a polar solvent.