Tag: M.W=600-700

Zhang, Xiaoyong; Mashima, Kazushi; Koyano, Kinko; Sayo, Noboru; Kumobayashi, Hidenori; Akutagawa, Susumu; Takaya, Hidemasa published the artcile< Synthesis of partially hydrogenated 2,2'-bis(diphenylphosphenyl)-1,1'-binaphthyl (BINAP) ligands and their application to catalytic asymmetric hydrogenation>, Recommanded Product: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is bisphosphine chiral partially hydrogenated synthesis ligand; ruthenium catalyst hydrogenation chiral phosphine ligand; asym hydrogenation ruthenium catalyst chiral phosphine; crystal structure chiral diphosphine ruthenium cation; mol structure chiral diphosphine ruthenium cation.

Three pairs of new axially dissym. bisphosphine ligands, (R)-(-)- and (S)-(+)-2,2′-bis(dicyclohexylphosphinyl)-1,1′-binaphthyl [ I, R = C6H11], (R)-(+)- and (S)-(-)-2,2′-bis(diphenylphosphinyl)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl [II, R = Ph], and (R)-(-)- and (S)-(+)-2,2′-bis(dicyclohexylphosphinyl)-5,5′,6,6,7,7′,8,8′-octahydro-1,1′-binaphthyl [II, R = C6H11], have been synthesized. The absolute configurations of the isomers I were determined by single-crystal x-ray diffraction of the linear 1:1 polymeric complex of (S)-(+)-2,2′-bis(dicyclohexylphosphinoyl)-1,1′-binaphthyl [III] and (2R,3R)-(-)-di-O-benzoyltartaric acid [(-)-DBT], and those of the isomers II were established on the basis of CD spectra of the phosphanes and their bisoxides. X-ray crystallog. studies of two cationic Rh1 complexes, [Rh{(S)-Cy-binap}(COD)]ClO4 [(S)-IV] and [Rh{(S)-H8-binap}(COD)]ClO4[(S)-V], revealed that complex (S)-IV possesses a disym. structure, while complex (S)-V has a pseudo-C2-symmetry and shows a significantly large dihedral angle between the two Ph rings [80.3(4)°]. The potentially of ligand II for asym. catalysis was demonstrated in RuII-catalyzed stereoselective hydrogenations of Me 2-(benzamidomethyl)-3-oxobutanoate, (in up to 92% d.e. and 99% e.e.) and geraniol (in 98% optical purity).

Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999) published new progress about Crystal structure. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Recommanded Product: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

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

Ashizawa, Tomoko; Yamada, Tohru published the artcile< Catalytic atropo-enantioselective preparation of axially chiral biaryl compounds>, Related Products of 139139-86-9, the main research area is biaryl lactone methanol chiral silver catalyst triisobutylamine ring opening; ester biaryl hydroxy derivative atropo stereoselective preparation; silver tetrafluoroborate binap derivative dynamic kinetic resolution catalyst.

The atropo-enantioselective ring-opening of biaryl lactones with methanol was catalyzed by an optically active AgBF4-phosphine complex to afford axially chiral biaryl compounds The addition of triisobutylamine provided a rate acceleration and increase in enantioselectivity in the reaction. Various types of axially chiral biaryl compounds were obtained with high enantioselectivity.

Chemistry Letters published new progress about Aromatic esters Role: SPN (Synthetic Preparation), PREP (Preparation) (biaryl). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Related Products of 139139-86-9.

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

Fukawa, Naohiro; Osaka, Takuya; Noguchi, Keiichi; Tanaka, Ken published the artcile< Asymmetric Synthesis and Photophysical Properties of Benzopyrano- or Naphthopyrano-Fused Helical Phosphafluorenes>, Electric Literature of 139139-86-9, the main research area is dialkynyl phosphine phenol linked tetrayne chiral rhodium catalyst cycloaddition; benzopyrano fused helical phosphafluorene derivative stereoselective preparation photophys property; naphthol linked tetrayne dialkynyl phosphine chiral rhodium catalyst cycloaddition; naphthopyrano fused helical phosphafluorene derivative stereoselective preparation photophys property; racemic benzopyrano fused helical phosphafluorene derivative crystal mol structure.

Enantioenriched benzopyrano- and naphthopyrano-fused helical phosphafluorenes have been synthesized by the rhodium-catalyzed enantioselective double [2 + 2 + 2] cycloaddition of dialkynyl phosphorus compounds with phenol- or naphthol-linked tetraynes. Photophys. properties of these phosphafluorenes are also disclosed.

Organic Letters published new progress about Alkynes, polyalkynes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) (tetraynes). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature of 139139-86-9.

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

Tsuchikama, Kyoji; Kuwata, Yusuke; Shibata, Takanori published the artcile< Highly Enantioselective Construction of a Chiral Spirocyclic Structure by the [2+2+2] Cycloaddition of Diynes and exo-Methylene Cyclic Compounds>, Application In Synthesis of 139139-93-8, the main research area is chiral spirocyclic compound preparation cycloaddition diyne exo methylene ketone.

The enantioselective [2+2+2] cycloaddition of 1,6-diynes with α-methylene lactones and cyclic ketones gave various chiral spirocyclic compounds The reaction proceeded with high enantioselectivity when the rhodium-xylylBINAP complex was used as a chiral catalyst. Not only exo-methylene cyclic compounds but also exo-methylene acyclic compounds could be used as coupling partners for diynes. The present protocol provides access to a new chiral library possessing a quaternary carbon center, including a spirocyclic system.

Journal of the American Chemical Society published new progress about Alkadiynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Application In Synthesis of 139139-93-8.

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

Kikuchi, Satoshi; Tsubo, Tatsuyuki; Ashizawa, Tomoko; Yamada, Tohru published the artcile< Extraordinary effect of microwave irradiation on asymmetric catalysis>, Name: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is atropo enantioselective ring opening reaction biaryl lactone.

We here report the effect of microwave irradiation on the atropo-enantioselective ring-opening reaction of biaryl lactones with dynamic-kinetic resolution catalyzed by AgBF4-phosphine complexes. The multimode microwave reactor with a cooling system was employed and the fiber-optic sensor was used for measurement of the accurate internal reaction temperature The reaction was accelerated by microwave irradiation without any loss of enantioselectivity at almost the same internal temperature as the conventional conditions.

Chemistry Letters published new progress about Microwave irradiation. 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Name: (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl.

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

Toure, Momar; Chuzel, Olivier; Parrain, Jean-Luc published the artcile< Asymmetric Rhodium-Directed anti-Markovnikov Regioselective Boracyclopentannulation>, Related Products of 139139-93-8, the main research area is asym rhodium directed anti Markovnikov regioselective boracyclopentannulation; crystal mol structure allylimidazolylidene borane imidazoloboracyclopentane compound.

A Shimoi-type activation of B-H bond of NHC-boranes by a diphosphine-ligated cationic Rh complex was applied in an unprecedented intramol. hydroboration reaction of simple olefins. The use of NHC-boranes as hydroborating reagents is still undisclosed due to their nonreactivity toward alkenes which could be explained by the high stability of this complex rendering it unable to provide a “”free”” borane hydroborating reagent. B-H bond Rh activation of NHC-borane circumvents this limitation, and asym. Rh-directed anti-Markovnikov boracyclopentannulation reaction led to a library of enantioenriched cyclic boranes in high yield (up to 94%) with high regio- (up to 100%) and enantioselectivity (er up to 99.2:0.8). This new activation mode of NHC-boranes highlights their use in organometallic chem. and offers a very good approach to access chiral cyclic NHC-boranes.

Journal of the American Chemical Society published new progress about Addition reaction (anti-Markovnikov). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Related Products of 139139-93-8.

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

Cederbaum, Fredrik; Lamberth, Clemens; Malan, Christophe; Naud, Fred; Spindler, Felix; Studer, Martin; Blaser, Hans-Ulrich published the artcile< Synthesis of substituted mandelic acid derivatives via enantioselective hydrogenation: Homogeneous versus heterogeneous catalysis>, Electric Literature of 325168-88-5, the main research area is stereoselective hydrogenation chlorophenylglyoxylate ruthenium homogeneous heterogeneous catalyst; chloromandelate stereoselective preparation ruthenium homogeneous heterogeneous catalyst; platinum cinchona catalyst stereoselective hydrogenation chlorophenylglyoxylate.

An extensive screening of both homogeneous and heterogeneous catalysts was carried out for the enantioselective hydrogenation of p-chlorophenylglyoxylic acid derivatives For p-chlorophenylglyoxylic amides only homogeneous Rh-diphosphine complexes gave satisfactory results, ees up to 87% were observed for the cy-oxo-pronop ligand. For Me p-chlorophenylglyoxylate both a homogeneous as well as a heterogeneous catalyst performed with ees >90%. A Pt catalyst modified with cinchona derivatives achieved 93% ee for the (R)- and 87% ee for the (S)-Me p-chloromandelate. A Ru-MeObiphep catalyst also reached 93% ee with TONs up to 4000 and TOFs up to 210 h-1. For all catalytic systems the effects of the metal, the nature of the chiral auxiliary and the solvent as well as of the reaction conditions were investigated. The homogeneous process was scaled up to the kg scale and the enantiomeric purity of the product was enhanced to >99% ee by two recrystallizations of the free p-chlorophenylmandelic acid.

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

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

Sarcher, Christian; Luehl, Anja; Falk, Florian C.; Lebedkin, Sergei; Kuehn, Michael; Wang, Cong; Paradies, Jan; Kappes, Manfred M.; Klopper, Wim; Roesky, Peter W. published the artcile< [2.2]Paracyclophanediyldiphosphane Complexes of Gold>, Electric Literature of 325168-88-5, the main research area is paracyclophanediyl diphosphine gold complex preparation crystal mol structure; alkyne hydroamination catalyst paracyclophanediyl diphosphine gold chloride complex; phosphorescence paracyclophanediyl diphosphine gold chloride complex.

Authors have prepared digold(I) complexes with the rigid-backbone diphosphine ligands PhanePhos, xyl-PhanePhos, and Ph2-GemPhos. All complexes were characterized by single-crystal x-ray diffraction, NMR, IR, Raman, and photoluminescence (PL) spectroscopy. [PhanePhos(AuCl)2] and [GemPhos(AuCl)2] show a very similar ligand scaffold, but different (aurophilic vs. nonaurophilic) intramol. Au-Au distances. Absorption and PL spectra of both compounds are quite similar. Theor. investigations reveal that the excited states are of different character (i.e., influenced by the Au-Au contacts). The resp. transition energies, however, lie close to each other, thus resulting in similar exptl. spectra. The gold atoms appear to produce a significant heavy-atom effect in the electronic relaxation dynamics. Thus, [PhanePhos(AuCl)2] and [GemPhos(AuCl)2] both show bright-green millisecond-long phosphorescence at low temperatures, although the latter is quenched at ambient temperature [PhanePhos(AuCl)2] and [GemPhos(AuCl)2] were also used as catalysts in the intra- and intermol. hydroamination of alkynes. Good to quant. conversions on a reasonable time scale were observed The overall performance of these catalysts in the studied reactions was similar, showing that Au-Au contacts do not have a major influence on the catalytic performance.

European Journal of Inorganic Chemistry published new progress about Alkynes Role: RCT (Reactant), RACT (Reactant or Reagent). 325168-88-5 belongs to class chiral-phosphine-ligands, and the molecular formula is C48H50P2, Electric Literature of 325168-88-5.

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

Miyauchi, Yuta; Noguchi, Keiichi; Tanaka, Ken published the artcile< Rhodium-Catalyzed One-Pot Intermolecular [2 + 2 + 2] Trimerization/Asymmetric Intramolecular [4 + 2] Cycloaddition of Two Aryl Ethynyl Ethers and 5-Alkynals>, Application In Synthesis of 139139-86-9, the main research area is rhodium catalyst trimerization asym cycloaddition aryl ethynyl ether alkynal; cyclohexadiene annulated enantioselective regioselective synthesis.

It has been established that a cationic Rh(I)/(R)-H8-BINAP complex catalyzes the one-pot intermol. [2+2+2] trimerization/asym. intramol. [4+2] cycloaddition of two aryl ethynyl ethers and 5-alkynals to produce annulated 1,4-cyclohexadienes possessing two stereogenic centers. E.g., rhodium-catalyzed reaction of 2-(ethynyloxy)naphthalene and MeCCCH2NTsCH2CHO gave 64% annulated 1,4-cyclohexadiene derivative (I).

Organic Letters published new progress about [4+2] Cycloaddition reaction (stereoselective). 139139-86-9 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Application In Synthesis of 139139-86-9.

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

Shibata, Takanori; Arai, Yoshikazu; Tahara, Yuki published the artcile< Enantioselective Construction of Quaternary Carbon Centers by Catalytic [2 + 2 + 2] Cycloaddition of 1,6-Enynes and Alkynes>, COA of Formula: C44H40P2, the main research area is bicyclic cyclohexadiene quaternary carbon stereocenter preparation; enyne alkyne enantioselective cycloaddition chiral rhodium catalysis.

The enantioselective [2 + 2 + 2] cycloaddition of 1,6-enynes and alkynes using chiral rhodium catalysts gave cycloadducts containing quaternary carbon stereocenters. Both sym. and unsym. alkynes and acetylene could be used as coupling partners, and the corresponding bicyclic cyclohexa-1,3-dienes were obtained in good to excellent ee.

Organic Letters published new progress about Alkenynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, COA of Formula: C44H40P2.

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