The invention is directed to ruthenium-based metathesis catalysts of the Grubbs-Hoveyda type. The new 2-aryloxy-substituted ruthenium catalysts described herein reveal rapid initiation behavior. Further, the corresponding styrene-based precursor compounds are disclosed. The catalysts are prepared in a cross-metathesis reaction starting from styrene-based precursors which can be prepared in a cost-effective manner. The new Grubbs-Hoveyda type catalysts are suitable to catalyze ring-closing metathesis (RCM), cross metathesis (CM) and ring-opening metathesis polymerization (ROMP). Low catalyst loadings are necessary to convert a wide range of substrates including more complex and critical substrates via metathesis reactions at low to moderate temperatures in high yields within short reaction times.

Embodiments in accordance with the present invention encompass an organoruthenium compound of the formula (I) or formula (II): ##STR00001##
Wherein X, L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, Ar.sub.1 and Ar.sub.2 are as defined herein. Also disclosed herein are the use of organoruthenium compound of formula (I) or formula (II) as (pre)catalysts for the olefin metathesis reactions, as well as to the process for carrying out the olefin metathesis reaction.

The disclosure relates to a selective head-to-head dimerization of conjugated diene compounds by a catalytic process in a reaction medium without solvent or with solvent comprising hydrocarbons, in the presence of a specific additive of the phenol type.

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.

An object of the present invention is to provide a method for suppressing the precipitation of polymers with a high concentration dissolved in a solvent in the operation termination step and suppressing the blockage of the apparatus by the polymers even when the polymers with a high concentration are precipitated, and the invention relates to a method for producing an α-olefin low polymer comprising a production operation step and an operation termination step, wherein the supply position of a supply liquid to a distillation column in the operation termination step is changed to a position lower than the supply position of a supply liquid to the distillation column in the production operation step.

Provided are a novel acyclic carbene ligand for ruthenium complex formation; a ruthenium complex catalyst using the ligand; a method of using the complex as a catalyst in an ethylene-metathesis ethenolysis reaction; a method of preparing the ruthenium complex catalyst; and a method of preparing a linear alpha-olefin, the method including the step of reacting a linear or cyclic alkene compound in the presence of the ruthenium complex catalyst. The acyclic carbene ligand of the present invention and the ruthenium complex catalyst using the same have high selectivity and turnover number for terminal olefin formation in an ethylene-metathesis ethenolysis reaction, and thus linear α-olefins may be prepared with a high yield.

A radio access network (RAN) configured to support real-time communications over a Long-Term Evolution (LTE) connection is described herein. When a request for a data transmission is received and a real-time communication session over the LTE connection is established, the RAN utilizes the LTE connection, not a New Radio (NR) connection, for the data transmission. When a request for a further real-time communication is received and there is an active data transmission session over the NR connection, the RAN performs at least one of ceasing to allocate traffic to the NR connection for downlink or reconfiguring the data transmission session to send data over the LTE connection.

In some embodiments, a process for producing a cyclic olefin includes introducing a polymer to a metathesis catalyst in a reaction vessel under reaction conditions. The process includes obtaining a cyclic olefin product comprising the cyclic olefin. In some embodiments, a process for producing a cyclic olefin includes introducing an article comprising a polymer to a metathesis catalyst in a reaction vessel under reaction conditions. The process includes obtaining a cyclic olefin product comprising the cyclic olefin.

This invention relates to a self cleaning reactor and to a process for the oligomerization of ethylene that employs a self-cleaning reactor. The reactor includes a mass of inert, particulate cleaning bodies that are entrained by the liquid in the reactor and scour the internal surfaces of the reactor during normal operation. This scouring action reduces the level of fouling on the reactor surfaces. Foulant material (polyethylene) is removed from the process on a continuous basis but the cleaning bodies remain within the reactor.

Disclosed herein are methods for removing acetylene from an ethylene gas stream wherein a catalyst reacts with the acetylene to polymerize said acetylene forming an ethylene gas stream substantially free of acetylene.