Patent classifications
B01J31/2452
Spiroketal-based C2-symmetric scaffold for asymmetric catalysis
Provided herein is a compound of formula (I): ##STR00001##
wherein each R is independently selected from the group consisting of C.sub.1-8 alkyl, C.sub.1-8 heteroalkyl having 1-4 heteroatoms independently selected from N, O, and S, C.sub.3-6 cycloalkyl, 3-10 membered heterocycloalkyl having 1-4 heteroatoms independently selected from N, O, and S, C.sub.6-10 aryl, and 5-10 membered heteroaryl having 1-4 heteroatoms independently selected from N, O, and S; each X is independently selected from OH, PAr.sub.2, P(O)Ar.sub.2, OPAr.sub.2, C.sub.3-6 cycloalkyl, 3-10 membered heterocycloalkyl having 1-4 heteroatoms independently selected from N, O, and S or each X together form O.sub.2PNR.sub.2; Ar is C.sub.6-10aryl; and each R is independently selected from hydrogen and C.sub.1-8 alkyl. Also provided are methods of making and using the compound of formula (I).
Metal-catalyzed alkoxycarbonylation of a lactone
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.
Method for producing a spirooxindole derivative
The present disclosure provides a method for efficiently producing and providing compounds having a spirooxindole skeleton, for example compounds having a spirooxindole skeleton and having antitumor activity that inhibit the interaction between Mdm2 protein and p53 protein, or intermediates thereof, using an asymmetric catalyst. Compounds having optically active tricyclic dispiroindole skeletons are obtained through catalytic asymmetric 1,3-dipolar cycloaddition reaction using ketimine as a reaction substrate and using a chiral ligand and a Lewis acid.
PINCER-TYPE LIGAND HAVING ACRIDANE STRUCTURE AND METAL COMPLEX USING THE SAME
Disclosed are a pincer-type ligand having a structurally rigid acridane structure and a metal complex consisting of the pincer-type ligand and a metal bound to each other, and exhibiting high reactivity and stability during a variety of bonding activation reactions. T-shaped complexes can be prepared from .sup.acriPNP(4,5-bis(diisopropylphosphino)-2,7,9,9-tetramethyl-9H-acrid in-10-ide), which is a pincer-type PNP ligand having an acridane structure, and metal complexes, which can be structurally rigid and thus exhibit excellent reactivity and stability based on minimized structural change thereof, can be prepared by introducing an acridane structure into the backbone thereof. The PNP ligand is structurally stable and has novel chemical properties, as compared to conventional similar ligands, and thus can be utilized in a wide range of catalytic reactions and material chemistry.
Method for the production of praziquantel and precursors thereof
The present invention provides methods of preparing Praziquantel, in particular (R)-Praziquantel and analogues thereof in a stereoselective manner. One method involves asymmetric hydrogenation of the following intermediate compound ##STR00001##
and subsequent cyclization.
Process for production of D-Sorbitol
The present invention relates to a new process for the production of D-sorbitol.
LOW SYSTEM MEMORY DETECTION
Methods, systems, and computer readable media may be operable to facilitate an anticipation of an execution of a process termination tool. An allocation stall counter may be queried at a certain frequency, and from the query of the allocation stall counter, a number of allocation stall counter increments occurring over a certain duration of time may be determined. If the number of allocation stall counter increments is greater than a threshold, a determination may be made that system memory is running low and that an execution of a process termination tool is imminent. In response to the determination that system memory is running low, a flag indicating that system memory is running low may be set, and one or more programs, in response to reading the flag, may free memory that is not necessary or required for execution.
Spiroketal-Based C2-Symmetric Scaffold For Asymmetric Catalysis
Provided herein is a compound of formula (I):
##STR00001##
wherein each R is independently selected from the group consisting of C.sub.1-8 alkyl, C.sub.1-8 heteroalkyl having 1-4 heteroatoms independently selected from N, O, and S, C.sub.3-6 cycloalkyl, 3-10 membered heterocycloalkyl having 1-4 heteroatoms independently selected from N, O, and S, C.sub.6-10 aryl, and 5-10 membered heteroaryl having 1-4 heteroatoms independently selected from N, O, and S; each X is independently selected from OH, PAr.sub.2, P(O)Ar.sub.2, OPAr.sub.2, C.sub.3-6 cycloalkyl, 3-10 membered heterocycloalkyl having 1-4 heteroatoms independently selected from N, O, and S or each X together form O.sub.2PNR.sub.2; Ar is C.sub.6-10aryl; and each R is independently selected from hydrogen and C.sub.1-8 alkyl. Also provided are methods of making and using the compound of formula (I).
PREPARATION METHOD OF L-NICOTINE
A preparation method for L-nicotine involves multiple steps. The resulting L-nicotine can have an optical purity of more than 99.9%, much higher than that of similar products in the current market. The total yield of synthesis reaches 50-60%.
MONOCARBONYL RUTHENIUM AND OSMIUM CATALYSTS
The invention relates to monocarbonyl complexes of ruthenium and osmium with bi- and tridentate nitrogen and phosphine ligands. The invention relates to methods for preparing these complexes and the use of these complexes, isolated or prepared in situ, as catalysts for reduction reactions of ketones and aldehydes both via transfer hydrogenation or hydrogenation with hydrogen.