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.

Methods for asymmetric cis-dihydroxylation (AD) of styrenes and conjugated dienes to produce cis-diols of styrene and conjugated diene or tetraols of conjugated diene with high yield (i.e., a yield 30%) and high enantioselectivity (i.e., an enantiometric excess 60%) are disclosed. The method uses an iron-based catalyst, such as one or more Fe(II) complexes, as the catalyst. The method generally includes: (i) maintaining a reaction mixture at a temperature for a period of time sufficient to form a product, where the reaction mixture contains a styrene or conjugated diene, one or more iron-based catalyst(s), an oxidant, and a solvent, and where the product contains a cis-diol or tetraol.

The subject of the invention are new sterically activated chelating ruthenium complexes with the formula 1a, easy to obtain by efficient chemical reactions. The invention also concerns the method of obtaining and using ruthenium complexes with formula 1a as precatalysts and/or catalysts in a wide spectrum of known olefin metathesis reactions.

##STR00001##

A process to prepare a relatively inexpensive utility fluid comprises contacting together ethylene and a coordination-insertion catalyst and, optionally, an alpha-olefin, in a continuously-fed backmixed reactor zone under conditions such that a mixture of a hyperbranched oligomer and a branched oligomer is formed. The hyperbranched oligomer has an average of at least 1.5 methine carbons per oligomer molecule, and at least 40 methine carbons per one-thousand total carbons, and at least 40 percent of the methine carbons is derived from the ethylene, and the average number of carbons per molecule is from 25 to 100, and at least 25 percent of the hyperbranched oligomer molecules has a vinyl group and can be separated from the branched oligomer, which has an average number of carbons per molecule of up to 20. The coordination-insertion catalyst is characterized as having an ethylene/octene reactivity ratio up to 20 and a kinetic chain length up to 20 monomer units.

The present application discloses novel amino-sulfide metal catalysts for organic chemical syntheses including hydrogenation (reduction) of unsaturated compounds or dehydrogenation of substrates. The range of hydrogenation substrate compounds includes esters, lactones, oils and fats, resulting in alcohols, diols, and triols as reaction products. The catalysts of current application can be used to catalyze a hydrogenation reaction under solvent free conditions. The present catalysts also allow the hydrogenation to proceed without added base, and it can be used in place of the conventional reduction methods employing hydrides of the main-group elements. Furthermore, the catalysts of the present application can catalyze a dehydrogenation reaction under homogenous and/or acceptorless conditions. As such, the catalysts provided herein can be useful in substantially reducing cost and improving the environmental profile of manufacturing processes for a variety of chemicals.

The present disclosure discloses a preparation method for 6-substituted chiral pure difluoropiperidine quinazoline derivative, in particular the 6-substituted chiral pure difluoropiperidine quinazoline derivative shown in Formula (I).

##STR00001##

The preparation method provided by the present disclosure is characterized by high chiral selectivity, high yield, and good process stability, which is of great significance for further production scale-up and commercialization of said solid drugs.

The subject matter of the invention is a stereoretentive ruthenium complex of the general formula 1a-Ru and/or 1b-Ru, in which all variables have the meanings defined in the description. The subject matter of the invention is also a method of preparing the ruthenium complex, an intermediate used in preparing the ruthenium complex, and the use of this ruthenium complex as a (pre) catalyst in olefin metathesis reactions such as ring-closing metathesis (RCM), homometathesis (self-CM), cross-metathesis (CM), and stereoretentive processes in olefin metathesis.

##STR00001##

In one aspect, the present disclosure encompasses polymerization systems for the copolymerization of CO.sub.2 and epoxides comprising 1) a catalyst including a metal coordination compound having a permanent ligand set and at least one ligand that is a polymerization initiator, and 2) a chain transfer agent having one or more sites capable of initiating copolymerization of epoxides and CO.sub.2, wherein the chain transfer agent contains one or more masked hydroxyl groups. In a second aspect, the present disclosure encompasses methods for the synthesis of polycarbonate polyols using the inventive polymerization systems. In a third aspect, the present disclosure encompasses polycarbonate polyol compositions characterized in that the polymer chains have a high percentage of OH end groups, a high percentage of carbonate linkages, and substantially all polycarbonate chains having hydroxyl end groups have no embedded chain transfer agent.

A formic acid decomposition catalyst system includes metal-ligand complexes having formula 1:

##STR00001##

wherein M is a transition metal; R.sub.1, R.sub.2 are independently C.sub.1-6 alkyl groups; o is 1, 2, 3, or 4; R.sub.3 are independently hydrogen, C.sub.1-6 alkyl groups, OR.sub.14, NO.sub.2, or halogen; R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, R.sub.13, are independently hydrogen or C.sub.1-6 alkyl groups; R.sub.14 is a C.sub.1-6 alkyl group; and X.sup. is a negatively charge counter ion.

The present application provides a main catalyst for preparing poly(4-methyl-1-pentene) and a use of the main catalyst. The main catalyst for preparing poly(4-methyl-1-pentene) of the present application has a structure represented by Formula I, in which R.sub.1 is selected from hydrogen or phenyl, and when R.sub.1 is selected from phenyl, R.sub.1 is fused with a naphthalene ring in the Formula I to form an anthracene ring; and R.sub.2 is selected from methyl or isopropyl. When the main catalyst of the present application is used in a catalytic system to catalyze homopolymerization of 4-methyl-1-pentene, the catalyst exhibits high catalytic activity, and the prepared poly(4-methyl-1-pentene) has high molecular weight, narrow molecular weight distribution and high isotacticity, and thus has broad market application prospects.