A process for the hydroformylation of ethylene, with a transition metal, e.g., rhodium, catalyst promoted with a bidentate ligand of Formula I, II or III in which each R.sub.1-R.sub.24 are independently a hydrogen, a hydrocarbyl group, an aromatic ring, a heteroaromatic ring or a halogen atom, or a heterocarbyl group. X.sub.1 is CH.sub.2 or O, while X.sub.2 is O or C(R.sub.25).sub.2, where each R.sub.25 may be the same or different and is a hydrogen, a cycloaliphatic group, an aromatic ring, a heteroaromatic ring or a halogen atom, or a heterocarbyl group, wherein two R.sub.25 groups may combine in a fused ring, and Y is a pyrrole group bound via the nitrogen atom to phosphorus, wherein each pyrrole group may bear multiple substituents selected from among the groups alkyl, alkoxy, acyl, carboxyl, carboxylate, cyano, —SO.sub.3H, sulfonate, amino, trifluoromethyl and halogen. ##STR00001##

Provided herein are methods of catalytic hydrosilylation, including triggerable methods, using metal-ligand complexes as catalysts, characterized by formula ML.sub.xD.sub.y; wherein: M is a metal; x is equal to the oxidation state of M; each D is independently a neutral coordinating ligand; y is zero or an integer selected from the range of 1 to 4; and each L is independently a mono-anionic ligand. L may be a η.sup.1,η.sup.2-β,β-disubstituted-ω-alkenyl ligand.

A long life catalyst is provided that is conveniently and inexpensively capable of being produced and that is highly active and has inhibited metal leakage. According to aspects of the present invention, a catalyst is provided that includes: a polymer including a plurality of first structural units and a plurality of second structural units; and metal acting as a catalytic center, wherein at least part of the metal is covered with the polymer, each of the plurality of first structural units has a first atom constituting a main chain of the polymer and a first substituent group bonded to the first atom, a second atom included in each of the plurality of second structural units is bonded to the first atom, and the second atom is different from the first atom, or at least one of all substituent groups on the second atom is different from the first substituent group.

The present invention provides highly efficient process for the preparation of enantiomerically enriched Sitagliptin of Formula (Ia). More particularly, a direct rhodium catalyzed asymmetric hydrogenation in the presence of bis-phosphine chiral ligand has been developed to yield enantiopure Sitagliptin product with the highest enantiomeric excess of 85-99.9%.

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A process for removing acetaldehyde efficiently and producing high-purity acetic acid stably is provided. Methanol is allowed to continuously react with carbon monoxide in a carbonylation reactor 1 in the presence of a catalyst system; the reaction mixture is continuously fed to a flasher 2 to form a volatile phase (2A) containing acetic acid and methyl iodide; the volatile phase (2A) is continuously fed to a splitter column 3 to form an overhead (3A) containing methyl iodide and acetaldehyde and a stream (3B) containing acetic acid; the volatile phase (2A) and/or the overhead (3A) is cooled by a first condenser C1, C3 at a predetermined cooling temperature; and the noncondensed gaseous component is further cooled by a second condenser C2, C4 to form a concentrate having a lower temperature and a higher acetaldehyde concentration. Acetaldehyde is efficiently removed by distilling the concentrate having a high acetaldehyde concentration.

Bisphosphites having at least one unsymmetric outer biphenol unit are useful for the hydroformylation of an olefin.

Use of transition metal complexes of the formula (I) in organic light-emitting diodes ##STR00001## where: M.sup.1 is a metal atom; carbene is a carbene ligand; L is a monoanionic or dianionic ligand; K is an uncharged monodentate or bidentate ligand selected from the group consisting of phosphines; CO; pyridines; nitriles and conjugated dienes which form a π complex with M.sup.1; n is the number of carbene ligands and is at least 1; m is the number of ligands L, where m can be 0 or ≧1; o is the number of ligands K, where o can be 0 or ≧1; where the sum n+m+o is dependent on the oxidation state and coordination number of the metal atom and on the denticity of the ligands carbene, L and K and also on the charge on the ligands carbene and L, with the proviso that n is at least 1, and also
an OLED comprising these transition metal complexes, a light-emitting layer comprising these transition metal complexes, OLEDs comprising this light-emitting layer, devices comprising an OLED according to the present invention, and specific transition metal complexes comprising at least two carbene ligands.

A ligand having the structure or its enantiomer; (I) wherein: each one of R.sub.a, R.sub.b, R.sub.c and R.sub.d is selected from alkyl, cycloalkyl, and aryl; the bridge group is selected from CH.sub.2NH; *CH(CH.sub.3)NH(C*,R); and the organocatalyst is an organic molecule catalyst covalently bound to the bridge group. Also, a catalyst having the structure or its enantiomer: (II) wherein: each one of R.sub.a, R.sub.b, R.sub.c and R.sub.d is selected from alkyl, cycloalkyl, and aryl; the bridge group is selected from CH.sub.2NH; *CH(CH.sub.3)NH(C*,R); and *CH(CH.sub.3)NH(C*,S); the organocatalyst is an organic molecule catalyst covalently bound to the bridge group; and M is selected from the group consisting of Rh, Pd, Cu, Ru, Ir, Ag, Au, Zn, Ni, Co, and Fe. ##STR00001##

Process for the continuous production of an optically active carbonyl compound by asymmetric hydrogenation of a prochiral α,β-unsaturated carbonyl compound with hydrogen in the presence of a homogeneous rhodium catalyst that has at least one chiral ligand, wherein a liquid reaction mixture comprising the prochiral α,β-unsaturated carbonyl compound is subjected in a first, backmixed reactor to a gas/liquid two-phase hydrogenation, and the liquid reaction mixture is then further hydrogenated in a second reactor, wherein the prochiral α,β-unsaturated carbonyl compound is employed in the first reactor in a concentration from 3% to 20% by weight. The process allows a high total conversion to the prochiral α,β-unsaturated carbonyl compound.

A hydroformylation process wherein the hydrolyzable organophosphorous ligand component of the catalyst is supplied as a stabilized ligand composition comprising a hydrolyzable organophosphorous ligand and, per 100 moles compound, from 0.05 to 13 acid-neutralizing equivalents of an acid scavenger.