An oxidative homocoupling method of synthesizing certain 2,2-bithiophenes from thiophenes using oxygen as the terminal oxidant is disclosed. In non-limiting examples, the method uses oxygen along with a catalytic system that includes palladium, an assistive ligand, and a non-palladium metal additive to catalyze one of the following reactions:

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Associated catalytic systems and compositions are also disclosed.

A catalyst having a specific structure and a method of preparing the catalyst is disclosed. A composition is also disclosed, which comprises: (A) an unsaturated compound including at least one aliphatically unsaturated group per molecule, subject to at least one of the following two provisos: (1) the (A) unsaturated compound also includes at least one silicon-bonded hydrogen atom per molecule; and/or (2) the composition further comprises (B) a silicon hydride compound including at least one silicon-bonded hydrogen atom per molecule. The composition further comprises (C) the catalyst. A method of preparing a hydrosilylation reaction product and a dehydrogenative silylation reaction product are also disclosed.

A chemoselective and reactive Mn(CF.sub.3-PDP) catalyst system that enables for the first time the strategic advantages of late-stage aliphatic CH hydroxylation to be leveraged in aromatic compounds. This discovery will benefit small molecule therapeutics by enabling the rapid diversification of aromatic drugs and natural products and identification of their metabolites.

A highly efficient, Z-selective ring-closing metathesis system for the formation of macrocycles using a stereoretentive, ruthenium-based catalyst supported by a dithiolate ligand is reported. This catalyst is demonstrated to be remarkably active as observed in initiation experiments showing complete catalyst initiation at 20 C. within 10 min. Using easily accessible diene starting materials bearing a Z-olefin moiety, macrocyclization reactions generated products with significantly higher Z-selectivity in appreciably shorter reaction times, in higher yield, and with much lower catalyst loadings than in previously reported systems. Macrocyclic lactones ranging in size from twelve-membered to seventeen-membered rings are synthesized in moderate to high yields (68-79% yield) with excellent Z-selectivity (95%-99% Z).

Provided herein are palladium (Pd) catalysts with improved performance in biological environments. In particular, formulations, methods of preparations, and storage conditions are provided that provide improved performance of Pd catalysts under protein-rich conditions.

An oxidative homocoupling method of synthesizing certain 2,2-bithiophenes from thiophenes using oxygen as the terminal oxidant is disclosed. In non-limiting examples, the method uses oxygen along with a catalytic system that includes palladium, an assistive ligand, and a non-palladium metal additive to catalyze one of the following reactions: ##STR00001## Associated catalytic systems and compositions are also disclosed.

The invention relates to molybdenum oxo alkylidene complexes of formula (I) wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and n are defined in the description, methods of making same and use thereof in metathesis reactions.

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The invention relates to oligomerization of olefins, such as ethylene, to higher olefins, such as a mixture of 1-hexene and 1-octene, using a catalyst system that comprises a) a source of chromium b) one or more activators and c) a phosphacycle-containing ligating compound. Additionally, the invention relates to a phosphacycle-containing ligating compound and a process for making said compound.

The present invention relates to a process for preparing nitrile rubbers having reduced molecular weight by metathesis of a first nitrile rubber in the presence of specific ruthenium complex catalysts that have particular N-heterocyclic carbene ligands.

Compound of formula 4 or formula 5

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wherein
L is a neutral ligand, preferably a nitrogen-containing heterocyclic carbene (NHC) such as carbene containing at least two nitrogen atoms, a cyclic aminoalkyl carbene (CAAC) or a bicyclic aminoalkyl carbene (BICAAC);
R.sup.1, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9, R.sup.10 and R.sup.11 are, independently, H, unbranched or branched C.sub.1-20 alkyl, C.sub.5-9 cycloalkyl, unbranched or branched C.sub.1-20 alkoxy, optionally bearing one or more halogen atoms, respectively; or aryl, optionally substituted with one or more of unbranched or branched C.sub.1-20 alkyl, C.sub.5-9 cycloalkyl, unbranched or branched C.sub.1-20 alkoxy, aryl, aryloxy, unbranched or branched C.sub.1-20 alkylcarbonyl, arylcarbonyl, unbranched or branched C.sub.1-20 alkoxycarbonyl, aryloxycarbonyl, heteroaryl, carboxyl, cyano, nitro, amido, aminosulfonyl, N-heteroarylsulfonyl, unbranched or branched C.sub.1-20 alkylsulfonyl, arylsulfonyl, unbranched or branched C.sub.1-20 alkylsulfinyl, arylsulfinyl, unbranched or branched C.sub.1-20 alkylthio, arylthio, sulfonamide, halogen or N(R.sup.y)(R.sup.z), wherein R.sup.y and R.sup.z are independently selected from H and C.sub.1-20 alkyl:
R.sup.2 is H, unbranched or branched C.sub.1-20 alkyl.