Abstract: Process for the preparation of crystalline vinylaromatic polymers with a predominantly syndiotactic structure which comprises polymerizing the vinylaromatic monomers, alone or mixed with at least another copolymerizable ethylenically unsaturated monomer, in the presence of a catalytic system essentially consisting of:a) an adduct between a derivative of titanium having the formula R.sub.1 R.sub.2 R.sub.3 R.sub.4 Ti and a calix-[n]-arene, or an oxa-calix-[n]-arene;b) a co-catalyst selected from an alkylalumoxane and a compound of boron having the formula (II):BX.sub.1 X.sub.2 X.sub.3or its salt.

Abstract: Process for the preparation of crystalline vinylaromatic polymers with a predominant syndiotactic structure which involves polymerizing vinylaromatic monomers in the presence of a catalytic system comprising: a titanium complex having general formula (I): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4, the same or different, represent a hydrogen atom or a C.sub.1 -C.sub.20 alkyl radical or a C.sub.6 -C.sub.20 arylalkyl or aryl radical, on the condition that at least one of these is different from hydrogen.

Abstract: Process for the preparation of (co) polymers of .alpha.-olefins which comprises polymerizing at least one .alpha.-olefin in the presence of a catalytic system consisting essentially of:a) a complex of a metal of groups VIB or VB having general formula (I):M(OCONRR').sub.n (I)wherein M represents a transition metal selected from the group consisting of Ti, Zr, H& and V; R and R', the same or different, represent a C.sub.1 -C.sub.12 aliphatic or C.sub.18 aromatic radical whereas n represents the oxidation state of the metal; andb) a cocatalyst consisting of aluminoxane.

Abstract: Process for the preparation of crystalline vinylaromatic polymers with a predominantly syndiotactic structure which comprises polymerizing the vinylaromatic monomers in the presence of a catalytic system consisting essentially of:a) a complex of titanium having the formula (I):Ti(OCONRR').sub.n (I)wherein R and R', the same or different, represent a C.sub.1 -C.sub.12 aliphatic radical or C.sub.6 -C.sub.12 aromatic radical whereas n is an integer equal to 3 or 4;b) a cocatalyst selected from aluminoxane and a compound of boron having formula (II):BX.sub.1 X.sub.2 X.sub.3 (II)wherein X.sub.1, X.sub.2 and X.sub.3, the same or different, represent a C.sub.1 -C.sub.20 perfluorinated hydrocarbon radical.

Abstract: A cobalt based catalyst, and the method for preparing it, are disclosed. The catalyst is obtained from the reaction between NaCo(CO).sub.4 and s-trichloro triazine and is advantageously used in the processes of carbonylation of naphthalene mono- and disulfonates in order to yield naphthalene esters and acids.

Abstract: Process of synthetizing ethylene-tetracarboxylic esters by duplication of lonic compounds of the formula: ##STR1## wherein X=COOR, Y=COOR' and R and R' represent an organic group, characterized in that the duplication is an oxidative duplication conducted in the presence of a catalyst consisting of the salt of a transition metal.

Abstract: The invention concerns a process for the preparation of the esters of an alkyltartronic acid by direct oxidation, with O.sub.2 or the like, at 30.degree.-200.degree. C., of the corresponding alkyl-malonic esters, in the presence of a catalytic system, comprising a salt of a transition metal, selected from Mn, Fe, Co and Cu, and an alkali-metal salt of an aliphatic carboxylic acid, optionally in the presence of a polar solvent.

Abstract: There is described a process for preparing carbonyl compounds of formula: ##STR1## by oxidation of compounds of formula: ##STR2## wherein X=--CN, --COOR, Y=--COOR.sub.1, --CN, and R, R.sub.1, like or unlike each other, are inert radicals, by employing oxygen or air as oxidants, at least a catalyst selected from the salts of organic or inorganic acids of Mn, Co, Cu and Fe, from 0 to 60 moles of an alkaline salt of an aliphatic carboxylic acid per gram-atom of catalyst metal, in a polar solvent, at temperatures ranging from 30.degree. C. to 200.degree. C. and maintaining the reaction medium anhydrous.The present invention relates to a process for preparing carbonyl compounds by catalytic oxidation of compounds containing an activated methylene group.

Abstract: Optically active methyl esters of arylpropionic acids are prepared by reaction of the corresponding vinylaromatic compounds with carbon monoxide and methyl alcohol in the presence of a palladium catalyst system consisting of a palladium compound associated with optically active diphenyl-neomenthylphosphine and with trifluoroacetic acid, at substantially atmospheric pressure and at a temperature comprised between 20.degree. and 80.degree. C. There is dealt with particular regioselective and enantioselective catalysis conditions.The products obtained consist of esters of arylpropionic acids or of the corresponding acids obtainable from them, and are useful intermediates in the synthesis of organic compounds, particularly of pharmaceutical products.