Abstract: The invention relates to a catalytic process for the synthesis of an alcohol by reaction of an epoxide with a nucleophilic compound containing a labile hydrogen, such as an alcohol, a phenol, a primary amine or a carboxylic acid.The catalyst is a metal complex of general formula (I)[M[Co(CO).sub.4 ].sub.2 ].sub.x in which x is equal to 1 or 2 and M denotes tin, lead and cadmium.The reaction preferably takes place in the presence of carbon monoxide.This process makes it possible to increase the yield and the selectivity of the reaction and the stereoselectivity for alcohol in the case of which the hydroxyl formed is attached to the least hindered carbon atom of the epoxide.The invention also relates to the new complexes of formula (I) in which x equals 2.It also relates to a process for the electrosynthesis of these new compounds by electroreduction of Co.sub.2 (CO).sub.

Abstract: The invention relates to a process for the preparation of acyl isocyanates of formula ##STR1## in which R is an alkyl radical, a substituted or unsubstituted naphthyl or phenyl radical or a substituted or unsubstituted aromatic heterocyclic radical, which consists in reacting an acyl halide of formula ##STR2## in which R has the above meaning and X denotes a fluorine, chlorine or bromine atom, with a sodium or potassium cyanate in the presence of a compound chosen from tin(IV), zinc or nickel(II) halides.The acyl isocyanates thus prepared are very useful for forming ureas or carbamates.

Abstract: Liquid/liquid extraction process for copper from an aqueous sulphuric acid solution acting on the concentrated mineral or semi-finished product to be treated.The extraction is carried out in an organic solvent containing in solution an extraction agent derived from 2-phenyl-4-acyl-(3H)-pyrazol-3-ones, with the phenyl group substituted or unsubstituted.Application to the upgrading of minerals.

Abstract: The present invention relates to a process for the synthesis of isocyanates and of isocyanate derivatives. Isocyanates are obtained by reacting an organic halide with a metal cyanate in an organic medium in the presence of a catalyst consisting of a complex of nickel with at least one organic ligand, in which complex the nickel is in the zero oxidation state.A carbamate or a urea, respectively, are obtained by a subsequent reaction with a hydroxy compound or a primary or secondary amine.Isocyanates and their derivatives are used especially either as refined synthesis agents for the production of pesticides and medications, or as monomers or comonomers for the preparation of many macromolecular compounds.

Abstract: The present invention relates to a process for the synthesis of isocyanates and of isocyanate derivatives. Isocyanates are obtained by reacting an organic halide with a metal cyanate in an organic medium in the presence of a catalyst consisting of a complex of nickel with at least one organic ligand, in which complex the nickel is in the zero oxidation state.A carbamate or a urea, respectively, are obtained by a subsequent reaction with a hydroxy compound or a primary or secondary amine.Isocyanates and their derivatives are used especially either as refined synthesis agents for the production of pesticides and medications, or as monomers or comonomers for the preparation of many macromolecular compounds.

Abstract: Liquid/liquid extraction process for copper from an aqueous sulphuric acid solution acting on the concentrated mineral or semi-finished product to be treated.The extraction is carried out in an organic solvent containing in solution an extraction agent derived from 2-phenyl-4-acyl-(3H)-pyrazol-3-ones, with the phenyl group subsitituted or unsubstituted.Application to the upgrading of minerals.

Abstract: The invention relates to new associations of strong bases, having the following general formula:n' RLi--n MZin which: n and n' are the numbers of mols of each compound, R is an alkyl or aryl radical, M is an alkali metal chosen from amongst lithium, sodium or potassium and Z is a hydride or an inorganic amide, the ratio n/n' being between 0.2 and 50.It is preferred to use bases in which the metal of the alkali metal amide or hydride is potassium or sodium. These associations are formed very rapidly and can be applied to anionic polymerization, in particular of conjugated dienes, in a solvent of low polarity or an apolar solvent.The polymers thus obtained contain a high percentage of 1,2 or 3,4 structures.

Abstract: The invention relates to new associations of strong bases, having the following general formula:n'RLi--n MZin which: n and n' are the numbers of mols of each compound, R is an alkyl or aryl radical, M is an alkali metal chosen from amongst lithium, sodium or potassium and Z is a hydride or an inorganic amide, the ratio n/n' being between 0.2 and 50.It is preferred to use bases in which the metal of the alkali metal amide or hydride is potassium or sodium. These associations are formed very rapidly and can be applied to anionic polymerisation, in particular of conjugated dienes, in a solvent of low polarity or an apolar solvent.The polymers thus obtained contain a high percentage of 1,2 or 3,4 structures.