Embodiments of the present disclosure provide for Rh(I) catalysts, methods of making alkenyl substituted arenes (e.g., allyl arene, vinyl arene, and the like), methods of making alkyl substituted arenes, and the like.

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 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.

Disclosed are methods of forming an epimer or a dehydrated isomer of a pyranose monosaccharide or a pyranose saccharide residue in an oligosaccharide or a glycoside.

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).

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst including a chromium compound coordinated with a ligand and a co-catalyst including an organoaluminum compound. The ligand may have a chemical structure: (R.sub.1)(R.sub.2)A-X—C(R.sub.3)(R.sub.4). A and C may be phosphorus. X may be B(R.sub.5), Si(R.sub.5).sub.2, N(R.sub.5), wherein R.sub.5 is an aryl group substituted with a halogen, halogenated alkyl or a silyl group, and wherein B, or N, or Si is bound to A and C. R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be independently chosen hydrocarbyl groups or heterohydrocarbyl groups.

A mixture M includes at least one compound A, selected from (a1) a compound of the general formula (I) and/or (a2) a compound of the general formula (I′), at least one compound B, selected from (b1) a compound of the general formula (II) and/or (b2) a compound of the general formula (II′) and/or (b3) a compound of the general formula (II″), and at least one compound C, selected from cationic germanium(II) compounds of the general formula (III).

Disclosed is a method for preparing an organic carboxylic ester by using a combined catalyst of an aryl bidentate phosphine ligand. The method includes subjecting a terminal olefin, carbon monoxide, and an alcohol to a hydroesterification reaction in the presence of a combined catalyst of a palladium compound, an aryl bidentate phosphine ligand, and an acidic additive, to generate an organic carboxylic ester having one more carbon atom than the terminal olefin.

Catalyst systems suitable for tetramerizing ethylene to form 1-octene may include a catalyst including a chromium compound coordinated with a ligand and a co-catalyst including an organoaluminum compound. The ligand may have a chemical structure: (R.sub.1)(R.sub.2)A-X—C(R.sub.3)(R.sub.4). A and C may be phosphorus. X may be B(R.sub.5), Si(R.sub.5).sub.2, N(R.sub.5), wherein R.sub.5 is an aryl group substituted with a halogen, halogenated alkyl or a silyl group, and wherein B, or N, or Si is bound to A and C. R.sub.1, R.sub.2, R.sub.3, and R.sub.4 may be independently chosen hydrocarbyl groups or heterohydrocarbyl groups.

The invention relates to a method of forming an olefin from a first olefin and a second olefin in a metathesis reaction, comprising step (i): (i) reacting the first olefin with the second olefin in the presence of a compound that catalyzes said metathesis reaction such that the molar ratio of said compound to the first or the second olefin is from 1:500 or less, and the conversion of the first or the second olefin to said olefin is at least 50%, characterized in that as compound that catalyzes said metathesis reaction a compound of the following formula is used: ##STR00001## wherein M is Mo or W; R.sup.1 is aryl, heteroaryl, alkyl, or heteroalkyl; optionally substituted; R.sup.2 and R.sup.3 can be the same or different and are hydrogen, alkyl, alkenyl, heteroalkyl, heteroalkenyl, aryl, or heteroaryl; optionally substituted; R.sup.5 is alkyl, alkoxy, heteroalkyl, aryl, heteroaryl, silylalkyl, silyloxy, optionally substituted; and R.sup.4 is a residue R.sup.6—X—, wherein X═O and R.sup.6 is aryl, optionally substituted; or X═S and R.sup.6 is aryl, optionally substituted; or X═O and R.sup.6 is (R.sup.7, R.sup.8, R.sup.9)Si; wherein R.sup.7, R.sup.8, R.sup.9 are alkyl or phenyl, optionally substituted; or X═O and R.sup.6 is (R.sup.10, R.sup.11, R.sup.12)C, wherein R.sup.10, R.sup.11, R.sup.12 are independently selected from phenyl, alkyl; optionally substituted; and to the catalysts used in the method.