Methods for controlling or adjusting the molecular weight and molecular weight distribution of an olefin polymer, such as an ethylene polymer, using an alkylaluminum compound are disclosed. In addition to the alkylaluminum compound, the catalyst systems contain a half-metallocene titanium phosphinimide compound and an activator.

Disclosed herein are methods for synthesizing low valence, bimetallic titanium compounds from half-metallocene titanium compounds and alkylaluminum compounds. The bimetallic titanium compounds can be used as components in catalyst systems for the polymerization of olefins.

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to the active metal center of the complex.

A phosphinimide catalyst system comprises: i) a phosphinimide pre-polymerization catalyst having two phosphinimide ligands, at least one of which is substituted by a phosphinimide moiety; and ii) a catalyst activator. The catalyst system polymerizes ethylene with an alpha-olefin to give high molecular weight ethylene copolymer.

The present invention relates to a new chemical synthesis, intermediates and catalysts useful for the preparation of the neprilysin (NEP) inhibitor sacubitril. It further relates to new intermediate compounds and their use for said new chemical synthesis route.

The present invention provides unimolecular metal complexes having increased activity in the copolymerization of carbon dioxide and epoxides. Also provided are methods of using such metal complexes in the synthesis of polymers. According to one aspect, the present invention provides metal complexes comprising an activating species with co-catalytic activity tethered to a multidentate ligand that is coordinated to the active metal center of the complex.

The present invention provides a bifunctional catalyst of the formula (1): wherein: each R.sup.1 is independently selected from an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted aralkyl group and an optionally substituted alkaryl group; Z represents a divalent organic linking moiety optionally containing one or more stereocenters; and EWG represents an electron-withdrawing group.
(R.sup.1).sub.3PNZNH-EWG(1)

The method for producing a surface-modified base material according to the present invention includes a step of bringing a base material having a polar group present on a surface thereof into contact with a hydrosilane compound having a molecular structure A and having a SiH group composed of a silicon atom of the molecular structure A and a hydrogen atom bonded to the silicon atom in the presence of a borane catalyst so as to allow a dehydrocondensation reaction to take place between the base material and the compound, thereby forming the base material surface-modified with the molecular structure A. This production method is capable of surface-modifying a base material at a lower temperature in a shorter time than conventional methods and allows a wide variety of options for the form, type, and application of the base material, the mode of the modification reaction, and the type of the molecular structure with which the base material is surface-modified.

Organometallic complexes are described which are useful as pre-polymerization catalysts which may form part of olefin polymerization catalyst systems. The catalyst systems find use in the polymerization of ethylene, optionally with one or more C.sub.3-12 alpha-olefin comonomers. The organometallic complexes are broadly represented by formula I: ##STR00001##
wherein L is a bridging group containing a contiguous chain of atoms connecting P with Cy, wherein the contiguous chain contains 2 or 3 atoms and wherein Cy is a cyclopentadienyl-type ligand. The olefin polymerization catalyst system is effective at polymerizing ethylene with alpha-olefins in a solution phase polymerization process at high temperatures and produces ethylene copolymers with high molecular weight and high degrees of alpha-olefin incorporation. Pre-metallation compounds, metallation processes and synthetic methods to make the organometallic complexes as well as polymerization processes are also described.

Organometallic complexes are described which are useful as pre-polymerization catalysts which may form part of olefin polymerization catalyst systems. The catalyst systems find use in the polymerization of ethylene, optionally with one or more C.sub.3-12 alpha-olefin comonomers. The organometallic complexes are broadly represented by formula I:

##STR00001##

wherein L is a bridging group containing a contiguous chain of atoms connecting P with Cy, wherein the contiguous chain contains 2 or 3 atoms and wherein Cy is a cyclopentadienyl-type ligand. The olefin polymerization catalyst system is effective at polymerizing ethylene with alpha-olefins in a solution phase polymerization process at high temperatures and produces ethylene copolymers with high molecular weight and high degrees of alpha-olefin incorporation. Pre-metallation compounds, metallation processes and synthetic methods to make the organometallic complexes as well as polymerization processes are also described.