A tetraanionic OCO pincer ligand metal-oxo-alkylidene complex is prepared from a trianionic pincer ligand supported metal-alkylidyne. The metal can be tungsten or other group 5-7 transition metal. The tetraanionic pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex can be used to polymerize cycloalkenes. The poly(cycloalkene)s are predominantly cis-alkene macrocyclics.

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.

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.

Compound of formula (4) or formula (5), 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.C is H, unbranched or branched C.sub.1-20 alkyl. ##STR00001##

A tetraanionic OCO pincer ligand metal-oxo-alkylidene complex is prepared from a trianionic pincer ligand supported metal-alkylidyne. The metal can be tungsten or other group 5-7 transition metal. The tetraanionic pincer ligand metal-oxo-alkylidene complex, a trianionic OCO pincer ligand metal complex, or a trianionic ONO pincer ligand metal complex can be used to polymerize cycloalkenes. The poly(cycloalkene)s are predominantly cis-alkene macrocyclics.

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).

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.

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 metal-catalyzed alkoxycarbonylation of a lactone is a method of alkoxycarbonylating a -lactone, specifically 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one. The method includes combining the -lactone with an alcohol in an organic solvent in the presence of a catalyst system that includes palladium or a salt thereof to form a reaction mixture, which is heated to 110-130 C. at a pressure of 20-50 bar for between 3-5 hours under flow of carbon monoxide gas. The product of the reaction is a substituted 2-octendioate diester. The alcohol may be methyl alcohol, n-butyl alcohol, 2-ethylhexanol, isobutyl alcohol, isopropyl alcohol, benzyl alcohol, or phenol. The solvent may be toluene, acetonitrile, or tetrahydrofuran. The method may include adding an acid to the reaction mixture, which may be dilute (about 5 mol %) sulfuric or p-toluenesulfonic acid. The catalyst system may also include a phosphine ligand.

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.