A process to produce a branched ethylene--olefin diene elastomer comprising combining a catalyst precursor and an activator with a feed comprising ethylene, C3 to C12 -olefins, and a dual-polymerizable diene to obtain a branched ethylene--olefin diene elastomer; where the catalyst precursor is selected from pyridyldiamide and quinolinyldiamido transition metal complexes. The branched ethylene--olefin diene elastomer may comprise within a range from 40 to 80 wt % of ethylene-derived units by weight of the branched ethylene--olefin diene elastomer, and 0.1 to 2 wt % of singly-polymerizable diene derived units, 0.1 to 2 wt % of singly-polymerizable diene derived units, and the remainder comprising C3 to C12 -olefin derived units, wherein the branched ethylene--olefin diene elastomer has a weight average molecular weight (M.sub.w) within a range from 100 kg/mole to 300 kg/mole, an average branching index (g.sub.avg) of 0.9 or more, and a branching index at very high M.sub.w (g.sub.1000) of less than 0.9.

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 catalytic activity tethered to a ligand that is coordinated to the active metal center of the complex.

A method for producing an oligomer, the method comprising a step of oligomerizing a polymerizable monomer comprising an olefin in the presence of a catalyst comprising an iron complex represented by the following Formula (1) and trialkylaluminum:

##STR00001##

[In Formula (1), R represents a hydrocarbyl group having 1 to 6 carbon atoms or an aromatic group having 6 to 12 carbon atoms, a plurality of R in the same molecule may be the same or different, R represents a free radical having an oxygen atom and/or a nitrogen atom, a plurality of R in the same molecule may be the same or different, and Y represents a chlorine atom or a bromine atom].

The present invention provides a novel catalyst of formula (I): wherein M is selected from Zn(H), Co(II), Mn(II), Mg(II), Fe(II), Cr(III)X or Fe(III)X, and the use thereof in polymerizing carbon dioxide and an epoxide.

Provided herein is a compound of formula (I):

##STR00001##

wherein each R is independently selected from the group consisting of C.sub.1-8 alkyl, C.sub.1-8 heteroalkyl having 1-4 heteroatoms independently selected from N, O, and S, C.sub.3-6 cycloalkyl, 3-10 membered heterocycloalkyl having 1-4 heteroatoms independently selected from N, O, and S, C.sub.6-10 aryl, and 5-10 membered heteroaryl having 1-4 heteroatoms independently selected from N, O, and S; each X is independently selected from OH, PAr.sub.2, P(O)Ar.sub.2, OPAr.sub.2, C.sub.3-6 cycloalkyl, 3-10 membered heterocycloalkyl having 1-4 heteroatoms independently selected from N, O, and S or each X together form O.sub.2PNR.sub.2; Ar is C.sub.6-10aryl; and each R is independently selected from hydrogen and C.sub.1-8 alkyl. Also provided are methods of making and using the compound of formula (I).

Iron-based homogeneous catalysts, supported by pincer ligands, are employed in the catalytic dehydrocoupling of ethanol to produce ethyl acetate and hydrogen. As both ethanol and ethyl acetate are volatile materials, they can be readily separated from the catalyst by applying vacuum at room temperature. The hydrogen by-product of the reaction may be isolated and utilized as a feedstock in other chemical transformations.

A new family of mononuclear organometallic complexes of a divalent metal bound to sequential tetradentate monoanionic {ONNN}-type ligands, and polymerization of cyclic esters such as lactides utilizing same are provided. Novel tetradentate monoanionic {ONNN}-type ligands usable for forming these complexes are also provided.

Chiral spirobiindane skeleton compound and preparation method thereof is disclosed in the present invention. The spirobiindane skeleton compound of the present invention having the structure formula of I or I; the preparation method for synthesizing the spirobiindane skeleton compound of the present invention comprising the following steps: in the presence of solvent and catalysts, the structure formula compound III reacted through intramolecular Friedel-Crafts reaction to obtain the compound of formula I; the catalyst is a Browsteric acidor Lewis acid. The preparation method of chiral fused spirobiindane skeleton compound of the present invention does not need to adopt chiral starting materials or chiral resolving agents, does not require chiral resolving steps, is simple in method, is simple in post-treatment, and is economic and environment friendly. High product yield, high product optical purity and chemical purity. The catalyst for the asymmetric reaction is obtained from the chiral spirobiindane skeleton ligand of the present invention, under the catalytic reagent of transition metal, the catalyzed hydrogenation reaction can arrive at a remarkable catalytic effect with a product yield of >99%, and a product ee value of up to >99%.

##STR00001##

The present invention relates to the technical field of organic chemistry, specifically an asymmetrical hydrogenation of an -ketonic acid compound, the technical proposal being as shown by the following formula: ##STR00001## Wherein R.sup.1 is a phenyl, a substituted phenyl, a naphthyl a substituted naphthyl, a C.sub.1-C.sub.6 alkyl or aralkyl, the substitute is a C.sub.1-C.sub.6 alkyl, a C.sub.1-C.sub.6 alkoxy, a halogen, the number of the substituents is 1-3. M is a chiral spiro-pyridyl amido phosphine ligand iridium complex having the following structure, ##STR00002## Wherein, R is hydrogen, 3-methyl, 4-.sup.tBu or 6-methyl

Disclosed herein are embodiments of a Pd(0) precursor complex and embodiments of phosphorus-based Pd(0) catalysts formed therefrom. Also disclosed are method embodiments for making the Pd(0) precursor complex and the phosphorus-based Pd(0) catalysts. The Pd(0) precursor complex can be used to generate, in situ, the phosphorus-based Pd(0) catalysts, in various different types of palladium-mediated coupling reactions.