325168-88-5| Chiral phosphine ligands

Cera, Gianpiero’s team published research in Organic Letters in 2012-03-02 | 325168-88-5

Organic Letters published new progress about Chiral ligands Role: CAT (Catalyst Use), USES (Uses). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Quality Control of 325168-88-5.

Cera, Gianpiero; Chiarucci, Michel; Mazzanti, Andrea; Mancinelli, Michele; Bandini, Marco published the artcile< Enantioselective gold-catalyzed synthesis of polycyclic indolines>, Quality Control of 325168-88-5, the main research area is furoindoline enantioselective preparation; dihydropyranylindoline enantioselective preparation; hydroxyalkynylindole preparation intramol cyclization gold catalyst.

The synthesis of architecturally complex polycyclic fused indolines is achieved in a chemo-, regio-, and stereodefined manner, via an enantioselective gold-catalyzed cascade hydroindolination/iminium trapping synthetic sequence. Highly functionalized tetracyclic fused furoindolines and dihydropyranylindolines are synthesized in moderate to good yields and enantiomeric excesses of up to 87%.

Referemce:
Phosphine ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate

Michon, Christophe’s team published research in Organometallics in 2013-10-14 | 325168-88-5

Organometallics published new progress about Allenes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Synthetic Route of 325168-88-5.

Michon, Christophe; Medina, Florian; Abadie, Marc-Antoine; Agbossou-Niedercorn, Francine published the artcile< Asymmetric Intramolecular Hydroamination of Allenes using Mononuclear Gold Catalysts>, Synthetic Route of 325168-88-5, the main research area is BINOL phosphoramidite preparation gold complex catalyzed asym hydroamination allene; imidazolidene gold BINOL phosphoramidite catalyzed enantioselective asym hydroamination allene.

The intramol. gold-catalyzed asym. hydroamination of allenes was studied by screening a series of mononuclear gold(I) and (III) complexes in combination with silver salts. Among the various chiral monophosphine and diaminocarbene ligands tried, the best catalysts arose from mononuclear gold(I) complexes synthesized from BINOL-based phosphoramidite ligands. The latest were improved by addition of bulky substituents at specific positions of the BINOL scaffold. The resulting gold(I) complexes were combined with selected silver salts to afford efficient catalysts for intramol. hydroamination of allenes at room temperature or below, with good conversions and enantioselectivities.

Hosseinabadi, Sareh Rezaei’s team published research in Separation and Purification Technology in 2015-06-16 | 325168-88-5

Separation and Purification Technology published new progress about Ceramic membranes (titania). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Application In Synthesis of 325168-88-5.

Hosseinabadi, Sareh Rezaei; Wyns, Kenny; Buekenhoudt, Anita; Van der Bruggen, Bart; Ormerod, Dominic published the artcile< Performance of Grignard functionalized ceramic nanofiltration membranes>, Application In Synthesis of 325168-88-5, the main research area is Grignard functionalized titania nanofiltration membrane solvent filtration performance.

A new generation of membranes modified by using Grignard reactions was recently introduced. These alkyl modified membranes have an enhanced hydrophobicity, and a potential for organic solvent nanofiltration (OSN). In this work, the solvent filtration performance and application potential of these Grignard functionalized membranes were further explored. To this purpose, the retention of model solutes using a variety of grafted and ungrafted membranes was investigated in 5 different solvent/solute test mixtures Experiments were performed with two different solvents, acetone with intermediate polarity and toluene as an apolar solvent, and 3 different solute classes, namely polyethylene glycol, polystyrene and a well-known catalyst ligand. The varying retention behavior can be explained by the changing affinity of solvents and solutes for the modified and unmodified membrane surfaces. Results of sorption tests confirm this conclusion. Subsequently, filtration of a phosphine mixture in isopropanol containing different solutes with similar size but varying polarity, showed the clear potential of affinity-based separations with Grignard modified membranes. A filtration test during four days revealed that the grafted groups are sufficiently stable. As a conclusion, Grignard functionalization of ceramic membranes allows to tune solvent-membrane-solute interactions in OSN in a controlled way for specific separations, without the extra complexity of swelling.

Tanielyan, Setrak K’s team published research in Organic Process Research & Development in 2006-10-31 | 325168-88-5

Organic Process Research & Development published new progress about 325168-88-5. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, HPLC of Formula: 325168-88-5.

Tanielyan, Setrak K.; Marin, Norman; Alvez, Gabriela; Augustine, Robert L. published the artcile< Two Efficient Enantioselective Syntheses of 2-Amino-1-phenylethanol>, HPLC of Formula: 325168-88-5, the main research area is aminophenylethanolstereoselective preparation.

Two enantioselective methods for the synthesis of 2-amino-1-phenylethanol have been developed. The first uses an enantioselective oxazaborolidine-catalyzed borane reduction of 2-chloroacetophenone (phenacyl chloride) to give the chiral chloro alc. in good yield with an ee in the 93-97% range. Reaction with dilute ammonium hydroxide produced the amino alc. in good yield with a high ee. The second approach involved the conversion of phenacyl chloride to the succinimidoacetophenone which was then hydrogenated using a chiral ruthenium complex in conjunction with a base and an optically active amine (Noyori procedure). This gave the optically active succinimido alc. in very good yield with an ee of 98%. Hydrolysis with dilute base produced the optically active amino alc. in very good yield and excellent enantioselectivity.

Felix, Ryan J’s team published research in Nature Chemistry in 2012-05-31 | 325168-88-5

Nature Chemistry published new progress about [3,3]-Sigmatropic rearrangement. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Computed Properties of 325168-88-5.

Felix, Ryan J.; Weber, Dieter; Gutierrez, Osvaldo; Tantillo, Dean J.; Gagne, Michel R. published the artcile< A gold-catalysed enantioselective Cope rearrangement of achiral 1,5-dienes>, Computed Properties of 325168-88-5, the main research area is gold catalysis enantioselective cope rearrangement achiral dienes.

Since the discovery of the Cope rearrangement in the 1940s, no asym. variant of the rearrangement of achiral 1,5-dienes has emerged, despite the successes that have been achieved with its heteroatom variants (Claisen, aza-Cope, and so on). This article reports the first example of an enantioselective Cope reaction that starts from an achiral diene. The new gold(I) catalyst derived from double Cl–abstraction of ((S)-3,5-xylyl-PHANEPHOS(AuCl)2), has been developed for the sigmatropic rearrangement of alkenyl-methylenecyclopropanes. The reaction proceeds at low temperature and the synthetically useful vinylcyclopropane products are obtained in high yield and enantioselectivity. D. functional theory calculations predict that: (1) the reaction proceeds via a cyclic carbenium ion intermediate, (2) the relief of strain in the methylenecyclopropane moiety provides the thermodn. driving force for the rearrangement and (3) metal complexation of the transition-state structure lowers the rearrangement barriers.

Mullen, Charles A’s team published research in Angewandte Chemie, International Edition in 2008 | 325168-88-5

Angewandte Chemie, International Edition published new progress about Alkenyl alcohols Role: RCT (Reactant), RACT (Reactant or Reagent). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, SDS of cas: 325168-88-5.

Mullen, Charles A.; Campbell, Alison N.; Gagne, Michel R. published the artcile< Asymmetric oxidative cation/olefin cyclization of polyenes: evidence for reversible cascade cyclization>, SDS of cas: 325168-88-5, the main research area is polyenol xylylphanephos platinum silver enantioselectively diastereoselectively regioselectively oxidative cyclization; fused oxygen containing heterocycle stereoselective preparation reaction determining step.

Activation of [(xylyl-phanephos)PtCl2] by silver generates an electrophilic catalyst that can enantioselectively, diastereoselectively, and regioselectively promote the stereospecific oxidative cyclization of polyene-ols. Mechanistic experiments indicate that the stereochem.-determining step is not the initial cyclization step, but rather a subsequent step in the reaction.

Konrad, Tina M’s team published research in Angewandte Chemie, International Edition in 2010 | 325168-88-5

Angewandte Chemie, International Edition published new progress about Aliphatic acids Role: SPN (Synthetic Preparation), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Application In Synthesis of 325168-88-5.

Konrad, Tina M.; Fuentes, Jose A.; Slawin, Alexandra M. Z.; Clarke, Matthew L. published the artcile< Highly Enantioselective Hydroxycarbonylation and Alkoxycarbonylation of Alkenes using Dipalladium Complexes as Precatalysts>, Application In Synthesis of 325168-88-5, the main research area is paracyclophane diphosphine palladium complex preparation enantioselective hydroxycarbonylation alkoxycarbonylation catalyst; styrene norbornene asym hydroxycarbonylation alkoxycarbonylation palladium phanephos catalyst.

A highly stereoselective process for hydroxycarbonylation and alkoxycarbonylation of alkenes [styrene, 4-(tert-butyl)styrene, norbornene] using (R)-PHANEPHOS- and (R)- or (S)-Xylyl-PHANEPHOS-bridged dipalladium complexes as precatalysts has been developed. The process operates below 100 °C, uses less than 1 equivalent of an acid promoter and delivers the product with up to 95% ee.

Pradal, Alexandre’s team published research in Tetrahedron in 2011 | 325168-88-5

Tetrahedron published new progress about Addition reaction catalysts, stereoselective. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Name: (S)-(+)-4,12-Bis(di(3,5-xylyl)phosphino)-[2.2]-paracyclophane.

Pradal, Alexandre; Chao, Chung-Meng; Vitale, Maxime R.; Toullec, Patrick Y.; Michelet, Veronique published the artcile< Asymmetric Au-catalyzed domino cyclization/nucleophile addition reactions of enynes in the presence of water, methanol and electron-rich aromatic derivatives>, Name: (S)-(+)-4,12-Bis(di(3,5-xylyl)phosphino)-[2.2]-paracyclophane, the main research area is asym gold catalyst cyclization nucleophilic addition enyne.

An efficient Au(I) catalytic system is described for the asym. domino cyclization/functionalization reactions of functionalized 1,6-enynes in the presence of an external nucleophile. The use of (R)-4-MeO-3,5-(t-Bu)2-MeOBIPHEP ligand associated with gold led to clean rearrangements implying the formal addition of an oxygen or carbon nucleophile to an alkene followed by a cyclization process. The enantiomeric excesses were highly dependent on the substrate/nucleophile combination. Very good enantiomeric excesses up to 98% were obtained in the case of substrates bearing larger groups (hindered diesters and disulfones) and in the case of hindered carbon nucleophiles.

Burk, Mark J’s team published research in Organic Letters in 2000-12-28 | 325168-88-5

Organic Letters published new progress about Alcohols Role: SPN (Synthetic Preparation), PREP (Preparation). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Category: chiral-phosphine-ligands.

Burk, Mark J.; Hems, William; Herzberg, Daniela; Malan, Christophe; Zanotti-Gerosa, Antonio published the artcile< A Catalyst for Efficient and Highly Enantioselective Hydrogenation of Aromatic, Heteroaromatic, and α,β-Unsaturated Ketones>, Category: chiral-phosphine-ligands, the main research area is enantioselective hydrogenation ketone ruthenium catalyst.

PhanePhos-ruthenium-diamine complexes catalyze the asym. hydrogenation of a wide range of aromatic, heteroaromatic, and α,β-unsaturated ketones with high activity and excellent enantioselectivity.

Alame, Mohamad’s team published research in Advanced Synthesis & Catalysis in 2008-04-30 | 325168-88-5

Advanced Synthesis & Catalysis published new progress about Hydrogenation. 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Electric Literature of 325168-88-5.

Alame, Mohamad; Pestre, Nathalie; de Bellefon, Claude published the artcile< Extensive re-investigations of pressure effects in rhodium-catalyzed asymmetric hydrogenations>, Electric Literature of 325168-88-5, the main research area is pressure effect rhodium catalysis asym hydrogenation.

The catalytic hydrogenation of three prochiral substrates Me Z-α-acetamidocinnamate (MAC), Me 2-acetamidoacrylate (M-Acrylate) and Et 4-methyl-3-acetamido-2-propanoate (E-EMAP) with rhodium precursors complexed with chiral diphosphines is reported at 1-30 bar hydrogen pressure. A library of 56 chiral diphosphines, including 23 BINAP derivatives, 7 JOSIPHOS, 5 BIPHEP, 3 DUPHOS derivatives, and 18 other ligands, was used. While it was generally accepted that high hydrogen pressure would result in lower ees, it is now demonstrated on a statistical basis that an equivalent distribution between beneficial and detrimental pressure effects on ee prevails and that the hydrogen pressure effect on enantioselectivity is not an isolated phenomenon since more than 33% of the reaction systems studied are strongly affected. In some case, the enantioselectivity can be improved up to 97% just by applying a higher hydrogen pressure. Extension of these conclusions to other non-chiral reagents is proposed.