The present invention relates to a method for olefin oligomerization and comprising i) injecting an olefin monomer and a solvent into a continuous stirred tank reactor (CSTR); ii) injecting an oligomerization catalyst system comprising a ligand compound, a transition metal compound, and a co-catalyst into the continuous stirred tank reactor; and iii) performing a multimerization reaction of the olefin monomer, wherein a ratio of the flowing rates of the olefin monomer and the solvent is from 1:1 to 2:1. In the method for olefin oligomerization according to the present invention, high linear alpha-olefin selectivity may be attained even with a small amount of a solvent used by controlling reaction conditions during the multimerization reaction of olefin by a continuous reaction using a continuous stirred tank reactor.

A method for producing an olefin oligomer is disclosed, in which an olefin oligomerization reaction is performed in the presence of an olefin oligomerization catalyst comprising (A) a chromium compound, (B) an amine compound of the general formula (1): ##STR00001##
(R.sup.1 to R.sup.4 represent a group such as a hydrocarbon group, Y represents a structure represented by —CR.sup.5R.sup.6—, R.sup.5 and R.sup.6 represent a group such as a hydrogen atom, and Z represents an integer of 1 to 10),
and (C) a compound such as an organometal compound; and the olefin oligomerization catalyst.

The present disclosure relates to a catalyst system comprising i) (a) a bicyclic 2-[(phosphinyl)aminyl] cyclic imine chromium salt or (b) a chromium salt and a bicyclic 2-[(phosphinyl)aminyl] cyclic imine and ii) an organoaluminum compound. The present disclosure also relates to a process comprising: a) contacting i) ethylene; ii) a catalyst system comprising (a) a 2-[(phosphinyl)aminyl] cyclic imine chromium salt complex or (b) a chromium salt and a bicyclic 2-[(phosphinyl)aminyl] cyclic imine; ii) an organoaluminum compound, and iii) optionally an organic reaction medium; and b) forming an oligomer product in a reaction zone.

Ethylene oligomerization catalysts include a solid support having surface hydroxyl groups on a surface of the solid support. Functional groups attached to the solid support through at least one covalent bond and coordinated with at least one catalytically active transition metal. Individual functional groups are attached to the solid support as products of condensation reactions of at least one hydrolysable group of precursor ligands with a corresponding surface group of the solid support. The precursor ligands have a general formula (Ph.sub.2P).sub.2N—R.sup.1-A, where R.sup.1 is C.sub.1-C.sub.40 hydrocarbylene or C.sub.1-C.sub.40 heterohydrocarbylene; and A is a hydrolysable group selected from trialkoxysilyl, halosilyl, carboxylates, esters, phosphonates, amines, imines, thiols, thiocarboxylates, or halides.

The present invention relates to catalyst composition for cyclic carbonate production from CO.sub.2 and olefins using halohydrin agent as the co-reactant under mild conditions, which can effectively catalyze the cyclic carbonate synthesis and provides good selectivity to cyclic carbonate, wherein said catalyst composition comprising: a) the metal complex as shown in structure (I):

##STR00001## wherein, M represents transition metal atom; R.sub.1, R.sub.2, and R.sub.3 represent independent group selected from hydrogen atom, halogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, amine group, phenyl group, benzyl group, cyclic hydrocarbon group comprising hetero atom, perfluoroalkyl group, or nitro group; R.sub.4 represents group selected from alkylene group, cycloalkylene group, or phenylene group; X represents group selected from halogen atom, acetate group, or triflate group; b) the halohydrin agent in at least one solvent; and c) at least one base.

The present invention relates to catalyst composition for cyclic carbonate production from CO.sub.2 and epoxides under mild conditions, which can effectively catalyze the cyclic carbonate synthesis and provides good selectivity to cyclic carbonate, wherein said catalyst composition comprising: a) the metal complex as shown in structure (I):

##STR00001## wherein, M represents transition metal atom; R.sub.1, R.sub.2, and R.sub.3 represent independent group selected from hydrogen atom, halogen atom, alkyl group, alkenyl group, alkynyl group, alkoxy group, amine group, phenyl group, benzyl group, cyclic hydrocarbon group comprising hetero atom, perfluoroalkyl group, or nitro group; R.sub.4 represents group selected from alkylene group, cycloalkylene group, or phenylene group; X represents group selected from hydrogen atom, acetate group, or triflate group; and b) the organic compound as the co-catalyst selected from compound containing nitrogen, compound of quaternary ammonium salts, or compound of iminium salts.

The present disclosure relates to a catalyst system comprising i) (a) an N.sup.2-phosphinyl bicyclic amidine chromium salt or (b) a chromium salt and an N.sup.2-phosphinyl bicyclic amidine and ii) an organoaluminum compound. The present disclosure also relate to a process comprising: a) contacting i) ethylene; ii) a catalyst system comprising (a) an N.sup.2-phosphinyl bicyclic amidine chromium salt complex or (b) a chromium salt and an N.sup.2-phosphinyl bicyclic amidine; ii) an organoaluminum compound, and iii) optionally an organic reaction medium; and b) forming an oligomer product in a reaction zone.

The present disclosure relates to a catalyst system comprising i) (a) a bicyclic 2-[(phosphinyl)aminyl] cyclic imine chromium salt or (b) a chromium salt and a bicyclic 2-[(phosphinyl)aminyl] cyclic imine and ii) an organoaluminum compound. The present disclosure also relate to a process comprising: a) contacting i) ethylene; ii) a catalyst system comprising (a) a 2-[(phosphinyl)aminyl] cyclic imine chromium salt complex or (b) a chromium salt and a bicyclic 2-[(phosphinyl)aminyl] cyclic imine; ii) an organoaluminum compound, and iii) optionally an organic reaction medium; and b) forming an oligomer product in a reaction zone.

Catalyst compositions and processes for the oligomerization of ethylene to 1-octene are described. The catalyst composition includes a triamino bisphospino (NPNPN) ligand system with specific phosphorous and nitrogen ligands. The terminal nitrogen atoms include linear alkyl hydrocarbons that differ in the number of carbon atoms by 3.

Provided are a chromium catalyst precursor, an ethylene oligomerization catalyst including the same, and a method of preparing an ethylene oligomer using the same. More particularly, a chromium catalyst precursor which may oligomerize ethylene with high activity and high selectivity in spite of not using methylaluminoxane (MAO) or modified-methylaluminoxane (MMAO), an oligomerization catalyst including the same, and a method of preparing an ethylene oligomer using the same are provided.