Chiral Rhodium Research Articles

Modification of (S)-N,N-Dimethyl-1-[(R)-1′,2-bis(diphenylphosphino)ferrocenyl]ethylamine (BPPFA) as a Ligand for Asymmetric Hydrogenation of Olefins Catalyzed by a Chiral Rhodium(I) Complex

Abstract Asymmetric homogeneous hydrogenation of prochiral olefins catalyzed by chiral rhodium(I) complexes was carried out by using several ferrocenylphosphines as ligands which play a key role of the chiral recognition. Modifications of BPPFA were made in order to examine a steric effect of the given substutient at the asymmetric center on the efficiency of the chiral ligands, indicating the parent BPPFA to be superior to the others examined for the asymmetric hydrogenation of highly functionalized olefins.

Asymmetric synthesis of dipeptides by means of homogeneous hydrogenation catalyzed by chiral rhodium complexes

Asymmetric hydrogenation of dehydrodipeptides, α-acylaminocinnamoyl-(S)-amino esters, catalyzed by rhodium complexes with chiral diphosphines gave either (R)-N-acylphenylalanyl-(S)-amino esters or (S)-N-acylphenylalanyl-(S)-amino esters with high diastereomeric purity up to 98–99% on using proper chiral ligands.

ASYMMETRIC HYDROGENATION OF α-ACYLAMINOCINNAMIC ACID CATALYZED BY CHIRAL RHODIUM COMPLEXES. REMARKABLE EFFECTS OF HYDROGEN PRESSURE ON STEREOSELECTIVITY

Abstract Remarkable effects of hydrogen pressure on the stereoselectivity were observed in the asymmetric hydrogenation of α-acylaminocinnamic acid and its derivatives catalyzed by chiral rhodium complexes. Effects of added triethylamine on the pressure dependency of stereoselectivity was also studied. Possible mechanisms are proposed.

Phosphinerhodium complexes as homogeneous catalysts: IX. Asymmetric hydrogenation of an olefin with catalysts formed from a chiral rhodium(I) car☐ylate and non-chiral phosphines

Rhodium car☐ylate complexes of the type [Rh(COD)(OOCR)] 2 have been prepared and used with phosphines to provide in situ catalysts for olefin hydrogenation. Asymmetric hydrogenation of α-acetamido cinnamic acid methyl ester has been observed using the car☐ylate complex prepared from l(+)-mandelic acid. The highest optical yield (13%) was achieved with trimethylphosphine as non-chiral ligand.

Chiral rhodium complexes of the dimenthylphosphine group attached to polystyrene for asymmetric hydrogenation of Z-α-acetamidocinnamic acid

New chiral rhodium complexes of a set of dimenthylphosphine-substituted, crosslinked styrene-divinylbenzene copolymers have been tested for the enantioselective hydrogenation of Z-α-acetamidocinnamic acid. The supported catalysts have been found to give optical yields up to 60% but suffer with respect to the catalytic activity.

Effective biomimetic route to D-(+)-pantothenate using asymmetric hydrogenation catalyzed by a chiral rhodium complex in the key step

Effective biomimetic route to D-(+)-pantothenate using asymmetric hydrogenation catalyzed by a chiral rhodium complex in the key step

Synthesis of a chiral rhodium catalyst anchored to an inorganic support and its application to asymmetric synthesis

Synthesis of a chiral rhodium catalyst anchored to an inorganic support and its application to asymmetric synthesis

Catalytic asymmetric synthesis of N-acetylphenylalanine in presence of chiral rhodium complex

The hydrogenation, ofα-acetylaminocinnamic acid under homogeneous conditions in the presence of the system (Py)3RhCl3·NaBH4·(S)-(-)-N-α-phenylethylformamide gives (R)-(-)-acetylphenylalanine in a yield of 66.2% and an optical yield of 73.8%.

Reduction asymetrique catalysee par des complexes de metaux de transition IV. synthese d'amines chirales au moyen d'un complexe de rhodium et d'isopropylidene dihydroxy-2,3 bis(diphenylphosphino)-1,4 butane (diop)

A chiral rhodium complex with (+)-diop as ligand is used as a catalyst in asymmetric synthesis leading to amines and N-acyl derivatives. Two kinds of reactions are investigated: asymetric hydrogenation of enamides and hydrosilylation of imines. Good optical yields are observed in the synthesis of N-acetyl α-phnenylethylamine (e.e. 45%) and N-acetyl α-phenylpropylamine (e.e. 83%). A strong solvent effect is observed, which can reverse the absolute configuration of tN-acetyl-α-phenylethylamine obtained by reduction of its enamide precursor. N-Benzyl-α-phenyl ethylamine is prepared by hydrosilylation with 65% optical purity. An asymmetric synthesis of 1,2,3,4-tetrahydropapaverine (e.e 38%) and related compounds is described.

Asymmetric hydrogenation by a chiral diphosphinite rhodium complex

Asymmetric hydrogenation has been successfully carried out using a rhodium complex with a chiral diphosphinite prepared from (+)-cyclohexane-(1S,2S)-diol.

Asymmetric catalysis by chiral rhodium complexes in hydrogenation and hydrosilylation reactions

Abstract

Chiral and diastereoisomeric rhodium(I) coordination compounds with carvone as bidentate ligand

The chiral dienone p-mentha-6,8-dien-2-one (carvone) coordinates readily with rhodium(I) to form complexes of pronounced stability. Novel diastereoisomeric planar coordination compounds of rhodium(I) containing two chiral bidentate ligands have been prepared for the first time. The synthesis of the compounds is simple, and the yields are high.

ChemInform Abstract: DIASTEREOMER SEPARATION AND CONFIGURATIONAL ASSIGNMENTS FOR A CHIRAL RHODIUM(III) BETA‐DIKETONATE COMPLEX

Chemischer InformationsdienstVolume 5, Issue 15 Organoelement Compounds ChemInform Abstract: DIASTEREOMER SEPARATION AND CONFIGURATIONAL ASSIGNMENTS FOR A CHIRAL RHODIUM(III) BETA-DIKETONATE COMPLEX GROVER W. JUN. EVERETT, GROVER W. JUN. EVERETTSearch for more papers by this authorANN JOHNSON, ANN JOHNSONSearch for more papers by this author GROVER W. JUN. EVERETT, GROVER W. JUN. EVERETTSearch for more papers by this authorANN JOHNSON, ANN JOHNSONSearch for more papers by this author First published: April 16, 1974 https://doi.org/10.1002/chin.197415430Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume5, Issue15April 16, 1974 RelatedInformation

Diastereomer separation and configurational assignments for a chiral rhodium(III) .beta.-diketonate complex

Diastereomer separation and configurational assignments for a chiral rhodium(III) .beta.-diketonate complex

Asymmetric hydrosilylation of ketones catalysed by a chiral rhodium complex

Synthesis of optically active alkoxysilanes by asymmetric hydrosilylation of ketones, in the presence of a chiral phosphine—rhodium complex, is described; optical yields up to 46% are observed.

Asymmetric catalytic reduction with transition metal complexes. II. Asymmetric catalysis by a supported chiral rhodium complex

Asymmetric catalytic reduction with transition metal complexes. II. Asymmetric catalysis by a supported chiral rhodium complex

Asymmetric hydrosilylation of ketones catalyzed by a chiral cationic rhodium complex

A cationic rhodium complex with an optically active phosphine as ligand can function as a catalyst for the asymmetric hydrosilylation of alkyl phenyl ketones.

ASYMMETRIC REDUCTION OF KETONES WITH A CATIONIC CHIRAL PHOSPHINE RHODIUM COMPLEX CATALYST

Abstract Methyl ethyl ketone, pinacoline and acetophenone are reduced asymmetrically to the corresponding alcohols with a chiral phosphine rhodium complex catalyst, [Rh(NBD) {(R)-PEtMePh}2]+PF6− (NBD = 2,5-norbornadiene).

Expanding the Scope of Enantioselective Rhodium-Catalyzed Allylic Substitution with a Nitrile Anion

In chemistry, a pair of molecules that have the same connectivity, but are non-superimposable mirror images, much like the human hand, are called enantiomers. In nature, enzymes are able to catalyze the selective synthesis of one of these forms. However, in the laboratory, we currently rely on metal-catalysts to fulfill this role. The efficiency and side effects of a drug can be drastically changed depending on which enantiomer is present. As a result, the pharmaceutical industry is interested in the selective synthesis of one enantiomer of a drug over the other. Furthermore, crucial drugs in the pharmaceutical industry contain a nitrile functional group (-C≡N), which are largely found on aromatic or fully-substituted carbons to prevent the release of toxic cyanide. This research involves the use of a chiral rhodium catalyst to direct the formation of one enantiomer over another in the synthesis of fully-substituted nitriles. Hence, the synthetic utility of this reaction is especially beneficial to the pharmaceutical industry. For example, one of the top 200 drugs in 2015, verapamil, is a nitrile containing compound. Verapamil is a calcium channel blocker prescribed to treat high blood pressure by relaxing the blood vessels to allow for easier blood flow. The presentation will describe the development and evaluation of the scope of this novel reaction and our efforts to develop a synthesis of (S)-verapamil.