Category: 139139-93-8

Sekine, Keisuke; Akaishi, Dai; Konagaya, Kakeru; Ito, Shigekazu published the artcile< Copper-Catalyzed Enantioselective Hydrosilylation of gem-Difluorocyclopropenes Leading to a Stereochemical Study of the Silylated gem-Difluorocyclopropanes>, Name: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is cyclopropene difluoro asym hydrosilylation silylboronate preparation chiral arylcyclopropane; copper chiral diphosphine monophosphine catalyst asym hydrosilylation difluorocyclopropene; asymmetric synthesis; copper catalysis; cyclopropanes; fluorine; racemization.

1-Aryl-2,2-difluorocyclopropenes ArC3HF2 undergo asym. hydrosilylation with pinBSiPhMe2 catalyzed by copper(I) complexes with mono- and bidentate chiral phosphines, affording trans-silylcyclopropanes ArCH(CF2)CHSiPhMe2 with up to 95% ee, which upon desilylation gave chiral 2-aryl-1,1-difluorocyclopropanes. Optically active cyclopropanes have been widely investigated especially from the views of pharmaceutical and agrochem. industries, and substituting one of the methylenes with the difluoromethylene unit should be promising for developing novel biol. relevant compounds and functional materials. In this paper, the copper-catalyzed enantioselective hydrosilylation of gem-difluorocyclopropenes to provide the corresponding chiral gem-difluorocyclopropanes is presented. The use of copper(I) chloride, chiral ligands including bidentate BINAPs and monodentate phosphoramidites, and silylborane Me2PhSi-Bpin accompanying sodium tert-butoxide in methanol was appropriate for the enantioselective hydrosilylation of the strained C:C double bond, and the resultant chiral difluorinated three-membered ring was unambiguously characterized. Subsequent activation of the silyl groups in enantio-enriched gem-difluorocyclopropanes showed substantial reduction of the enantiopurity, indicating cleavage of the distal C-C bond leading to the transient acyclic intermediates.

Chemistry – A European Journal published new progress about Chiral ligands Role: CAT (Catalyst Use), USES (Uses) (chiral phosphines). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Name: (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

Goulioukina, Nataliya S.; Shergold, Ilya A.; Rybakov, Victor B.; Beletskaya, Irina P. published the artcile< One-Pot Two-Step Synthesis of Optically Active α-Amino Phosphonates by Palladium-Catalyzed Hydrogenation/Hydrogenolysis of α-Hydrazono Phosphonates>, Category: chiral-phosphine-ligands, the main research area is chiral hydrazono amino phosphonate palladium catalyzed enantioselective hydrogenation; crystal structure chiral hydrazono amino phosphonate; mol structure chiral hydrazono amino phosphonate; amino phosphonate chiral preparation optical activity.

An efficient and convenient 1-pot procedure for the stereoselective catalytic synthesis of ring-substituted [amino(phenyl)methyl]phosphonates was developed. The enantioselective hydrogenation of easily available diisopropyl (Z)-[aryl(phenylhydrazono)methyl]phosphonates using Pd(II) acetate as a precatalyst, (R)-2,2′-bis(diphenylphosphino)-5,5′-dichloro-6,6′-dimethoxy-1,1′-biphenyl [(R)-Cl-MeO-BIPHEP] as a ligand, and (1S)-(+)-10-camphorsulfonic acid as an activator in a mixture of 2,2,2-trifluoroethanol and CH2Cl2 at ambient temperature gave corresponding [aryl(2-phenylhydrazino)methyl]phosphonates. The subsequent cleavage of the N-N bond was accomplished with H2 after the addition of Pd on C and MeOH into crude reaction mixture to afford the optically active [amino(aryl)methyl]phosphonates. The method is operationally simple and provides an appreciable enantioselectivity up to 98% ee.

Advanced Synthesis & Catalysis published new progress about Crystal structure. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Category: chiral-phosphine-ligands.

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

Li, Min; Li, Bin; Xia, Hong-Feng; Ye, Danru; Wu, Jing; Shi, Yifeng published the artcile< Mesoporous silica KIT-6 supported superparamagnetic CuFe2O4 nanoparticles for catalytic asymmetric hydrosilylation of ketones in air>, Product Details of C44H40P2, the main research area is silica copper iron oxide nanoparticle catalyst ketone asym hydrosilylation.

A diverse range of prochiral ketones were reduced in air with high yields and good-to-excellent enantioselectivities (up to 97% ee) in the presence of a heterogeneous catalyst system, which was in situ formed from catalytic amounts of superparamagnetic CuFe2O4 nanoparticles supported on mesoporous silica KIT-6 and non-racemic dipyridylphosphine ligand, the stoichiometric hydride donor polymethylhydrosiloxane (PMHS) as well as certain amounts of additives. The magnetically separable catalysts could be efficiently reused 4 times without apparent loss of both the activity and enantioselectivity.

Green Chemistry published new progress about Catalyst supports. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Product Details of 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

Yoshida, Tomoka; Tajima, Yuki; Kobayashi, Masayuki; Masutomi, Koji; Noguchi, Keiichi; Tanaka, Ken published the artcile< Rhodium-Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides>, Electric Literature of 139139-93-8, the main research area is cycloheptadiene diastereoselective preparation rhodium catalyst reaction mechanism; spiro cyclohexadiene stereoselective preparation rhodium catalyst reaction mechanism; alkyne unsaturated ketone cycloaddition; asymmetric catalysis; cycloaddition; heterocycles; rhodium; synthetic methods.

A cationic rhodium(I)/H8-binap complex catalyzed the [3+2+2] cycloaddition of 1,6-diynes with cyclopropylideneacetamides which produced cycloheptadiene derivatives, e.g., I, through cleavage of cyclopropane rings. A cationic rhodium(I)/(S)-binap complex catalyzed the enantioselective [2+2+2] cycloaddition of terminal alkynes, acetylenedicarboxylates, and cyclopropylideneacetamides which produced spiro-cyclohexadiene derivatives, e.g., II, which retained the cyclopropane rings.

Angewandte Chemie, International Edition published new progress about Alkynes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature 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

Arao, Takafumi; Kondo, Kazuhiro; Aoyama, Toyohiko published the artcile< Asymmetric construction of quaternary carbon stereocenter by Pd-catalyzed intramolecular α-arylation>, Name: (S)-(-)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is quaternary carbon stereocenter palladium catalyzed intramol arylation; enantioselective indolone preparation palladium catalyzed.

The catalyst comprised of Pd(OAc)2 and H8-BINAP provides good reaction conversions for a catalytic enantioselective intramol. α-arylation of N-(2-bromophenyl)-N-methyl-2-arylpropanamides. The corresponding 3-substituted indol-2-ones are formed with up to 68% enantioselectivity.

Chemical & Pharmaceutical Bulletin published new progress about Arylation (intramol.). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Name: (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

Najera, Carmen; de Gracia Retamosa, M.; Sansano, Jose M.; de Cozar, Abel; Cossio, Fernando P. published the artcile< Enantioselective synthesis of polysubstituted prolines by Binap-silver-catalyzed 1,3-dipolar cycloadditions>, Related Products of 139139-93-8, the main research area is polysubstituted proline derivative asym preparation; iminoester maleimide asym dipolar cycloaddition silver BINAP; silver BINAP asym dipolar cycloaddition catalyst.

The enantioselective 1,3-dipolar cycloaddition reaction of stabilized azomethine ylides, generated from iminoesters, with maleimides was efficiently achieved by intermediacy of an equimolar mixture of chiral (R)- or (S)-Binap and AgClO4. The high stability of the titled catalytic metal-complex to light exposure and its insolubility in toluene made possible its recovery and reutilization in other new process. In order to get a better understanding of the behavior of these chiral catalysts, we have carried out DFT1 calculations demonstrating the exptl. observed high enantio- and endo-selectivity through a very asynchronous transition state.

Tetrahedron: Asymmetry published new progress about 1,3-Dipolar cycloaddition reaction, stereoselective. 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

Kita, Yusuke; Hida, Shoji; Higashihara, Kenya; Jena, Himanshu Sekhar; Higashida, Kosuke; Mashima, Kazushi published the artcile< Chloride-Bridged Dinuclear Rhodium(III) Complexes Bearing Chiral Diphosphine Ligands: Catalyst Precursors for Asymmetric Hydrogenation of Simple Olefins>, Electric Literature of 139139-93-8, the main research area is diarylalkane enantioselective preparation; diarylalkene enantioselective hydrogenation rhodium catalyst; asymmetric catalysis; hydrogenation; reaction mechanisms; rhodium.

Efficient rhodium(III) catalysts were developed for asym. hydrogenation of simple olefins. A series of chloride-bridged dinuclear rhodium(III) complexes were synthesized from the rhodium(I) precursor [RhCl(cod)]2, chiral diphosphine ligands, and hydrochloric acid. Complexes from the series acted as efficient catalysts for asym. hydrogenation of (E)-prop-1-ene-1,2-diyldibenzene and its derivatives without any directing groups, in sharp contrast to widely used rhodium(I) catalytic systems that require a directing group for high enantioselectivity. The catalytic system was applied to asym. hydrogenation of allylic alcs., alkenylboranes, and unsaturated cyclic sulfones. Control experiments support the superiority of dinuclear rhodium(III) complexes over typical rhodium(I) catalytic systems.

Angewandte Chemie, International Edition published new progress about Aryl alkenes Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Electric Literature 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

Kashima, Kenichi; Ishii, Masahiro; Tanaka, Ken published the artcile< Synthesis of Pyridylphosphonates by Rhodium-Catalyzed [2+2+2] Cycloaddition of 1,6- and 1,7-Diynes with Diethyl Phosphorocyanidate>, Formula: C44H40P2, the main research area is diyne cycloaddition enantioselective phosphorocyanidate preparation pyridylphosphonate fluorescence.

The convenient and atom-economical synthesis of substituted bicyclic pyridylphosphonates was achieved by the cationic Rh(I)/H8-binap-complex-catalyzed [2+2+2] cycloaddition of 1,6- and 1,7-diynes with di-Et phosphorocyanidate. These reactions may proceed via an azarhodacyclopentadiene intermediate in addition to the rhodacyclopentadiene intermediate.

European Journal of Organic Chemistry 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, 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

Tabuchi, Sho; Hirano, Koji; Miura, Masahiro published the artcile< Palladium-Catalyzed Asymmetric Benzylic Alkylation of Active Methylene Compounds with α-Naphthylbenzyl Carbonates and Pivalates>, Reference of 139139-93-8, the main research area is palladium catalyst asym benzylic alkylation active methylene compound; asymmetric catalysis; kinetic resolution; ligand effects; palladium; synthetic methods.

A Pd/(R)-H8-BINAP-catalyzed asym. benzylic alkylation of active methylene compounds has been developed. The reaction proceeds without the use of an external base, and the starting racemic diarylmethyl carbonates are converted into the optically active coupling products which contain the benzylic chiral stereocenter by a dynamic kinetic asym. transformation (DYKAT). Addnl., with suitable carbonates bases, the same palladium catalysis allows the corresponding pivalates to be adopted in the same DYKAT process.

Angewandte Chemie, International Edition published new progress about Active methylene compounds Role: RCT (Reactant), RACT (Reactant or Reagent). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Reference 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

Chang, Xin; Ma, Pei-Long; Chen, Hong-Chao; Li, Chuan-Ying; Wang, Peng published the artcile< Asymmetric Synthesis and Application of Chiral Spirosilabiindanes>, Quality Control of 139139-93-8, the main research area is alkenyldihydrosilane preparation rhodium catalyzed asym double hydrosilation spirocyclization; spirosilabiindane chiral preparation reaction aminophosphine; phosphoramidite spirosilabiindane chiral preparation catalyst ligand asym hydrogenation carboamination; crystal structure chiral spirosilabiindane diol derivative phosphoramidite; mol structure chiral spirosilabiindane diol derivative phosphoramidite; asymmetric catalysis; ligand design; silanes; spirocompounds; synthetic methods.

Reported here is the development of a class of chiral spirosilabiindane scaffolds by Rh-catalyzed asym. double hydrosilation, for the 1st time. Enantiopure SPSiOL (spirosilabiindane diol), a new type of chiral building block for the preparation of various chiral ligands and catalysts, was readily prepared on >10 g scale using this protocol. The potential of this new spirosilabiindane scaffold in asym. catalysis was preliminarily demonstrated by development of the corresponding monodentate phosphoramidite ligands (SPSiPhos), which were used in both a Rh-catalyzed hydrogenation and a Pd-catalyzed intramol. carboamination.

Angewandte Chemie, International Edition published new progress about Alkenes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation) (bis(alkenyl)dihydrosilanes). 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Quality Control 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