Tag: M.W=600-700

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.

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.

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

Nishida, Goushi; Noguchi, Keiichi; Hirano, Masao; Tanaka, Ken published the artcile< Asymmetric assembly of aromatic rings to produce tetra-ortho-substituted axially chiral biaryl phosphorus compounds>, Related Products of 139139-86-9, the main research area is asym aromatic ring substituted tetra axially chiral biaryl phosphorus; dicyclohexylphosphinoyl methoxynaphthalenyl dihydroisobenzofuran preparation crystal mol structure.

Densely substituted title compounds can be obtained efficiently through an enantioselective [2 + 2 + 2] cycloaddition catalyzed by a cationic Rh1/H8-binap (H8-binap = 2,2′-bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl) complex. This method is highly up to > 99% yield practical in view of the ready access to up to 98% ee substrates, mild reaction conditions, operational simplicity, and high catalytic activity. The crystal structure of one of the biaryl phosphorus compound is described.

Angewandte Chemie, International Edition published new progress about Crystal structure. 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

Xu, Qi; Zhang, Huan; Ge, Fang-Bei; Wang, Xiao-Mei; Zhang, Peng; Lu, Chuan-Jun; Liu, Ren-Rong published the artcile< Cu(I)-Catalyzed Asymmetric Arylation of Pyrroles with Diaryliodonium Salts toward the Synthesis of N-N Atropisomers>, Computed Properties of 139139-93-8, the main research area is nitrogen atropisomer preparation enantioselective; pyrrole diaryliodonium salt asym arylation copper catalyst.

The copper(I) catalysis using a bis(phosphine) dioxide ligand could catalyze the desym. C-H arylation of prochiral bipyrroles was reported. More than 50 nitrogen-nitrogen atropisomers I [R1 = Ph, 3-ClC6H4, 2-naphthyl, etc.; R2 = Me, Et, Bn, etc.; R3 = Me, Et, i-Pr; R4 = H, Me; R1R4 = CH=CH-CH=CH; Ar = Ph, 4-MeC6H4, 3-ClC6H4, etc.] were achieved in good to excellent yields with excellent enantioselectivities (≤97% yield, ≤98% ee). The reaction proceeded under mild conditions with good functional group compatibility on arenes and diaryliodonium salts. Moreover, this principle enabled iterative arylation of the bipyrroles to enantioselectively arylate different positions during the catalysis of copper.

Organic Letters published new progress about Arylation. 139139-93-8 belongs to class chiral-phosphine-ligands, and the molecular formula is C44H40P2, Computed Properties 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

Zhang, Tian-Yuan; Deng, Yi; Wei, Kun; Yang, Yu-Rong published the artcile< Enantioselective Iridium-Catalyzed Allylic Alkylation of Racemic Branched Alkyl-Substituted Allylic Acetates with Malonates>, Safety of (R)-2,2′-Bis(diphenylphosphino)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl, the main research area is alkenyl ester preparation enantioselective; alkyl substituted allylic acetate malonate allylic alkylation iridium catalyst.

The regio- and enantioselective allylic substitution of branched alkyl-substituted allylic acetates employing malonates was achieved through a process that called for Krische’s π-allyliridium C,O-benzoate catalyst. The protocol reported herein was applied to a diverse set of branched alkyl substrates that are generally not well tolerated in the other two types of Ir-catalyzed allylation.

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

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.

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.

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

Guo, Yonghong; Liu, Meng-Meng; Zhu, Xujiang; Zhu, Liru; He, Chuan published the artcile< Catalytic Asymmetric Synthesis of Silicon-Stereogenic Dihydrodibenzosilines: Silicon Central-to-Axial Chirality Relay>, Formula: C44H40P2, the main research area is crystal structure mol silicon dihydrodibenzosiline heterocycle biaryl chiral preparation; rhodium catalyst asym preparation chiral silicon dihydrodibenzosiline axial; axial chirality; chirality relay; enantioselective C−H silylation; silicon-central chirality; silicon-stereogenic monohydrosilanes.

A Rh-catalyzed asym. synthesis of silicon-stereogenic dihydrodibenzosilines featuring axially chiral 6-membered bridged biaryls is demonstrated. In the presence of a RhI catalyst with a chiral diphosphine ligand, a wide range of dihydrodibenzosilines containing both silicon-central and axial chiralities are conveniently constructed in excellent enantioselectivities via dehydrogenative C(sp3)-H silylation. Absolute configuration anal. by single-crystal X-ray structures revealed a novel silicon central-to-axial chirality relay phenomenon, which we believe will inspire further research in the field of asym. catalysis and chiroptical materials.

Angewandte Chemie, International Edition published new progress about Biaryls Role: PRP (Properties), RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 139139-86-9 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

Ogaki, Shuichiro; Shibata, Yu; Noguchi, Keiichi; Tanaka, Ken published the artcile< Enantioselective Synthesis of Axially Chiral Hydroxy Carboxylic Acid Derivatives by Rhodium-Catalyzed [2 + 2 + 2] Cycloaddition>, Application of C44H40P2, the main research area is naphthalenepropynoic acid derivative diyne chiral rhodium bisphosphine catalyst cycloaddition; arylnaphthalene hydroxy carboxylic acid derivative regioselective stereoselective preparation; axially chiral arylnaphthalene regioselective stereoselective preparation.

Axially chiral hydroxy carboxylic acid derivatives were successfully synthesized with high yields and ee values by the cationic rhodium(I)/axially chiral biaryl bisphosphine complex-catalyzed enantioselective [2+2+2] cycloaddition of diynes with naphthalenepropynoic acid derivatives Axially chiral hydroxy and dihydroxy carboxylic acid derivatives, bearing the aryl group at the ortho-position of the alkoxycarbonyl group, were also synthesized with high regio- and enantioselectivity.

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

Xu, Jian-Lin; Xu, Zhe-Yuan; Wang, Zi-Lu; Ma, Wei-Wei; Sun, Xin-Yue; Fu, Yao; Xu, Yun-He published the artcile< Copper-Catalyzed Regiodivergent and Enantioselective Hydrosilylation of Allenes>, Reference of 139139-93-8, the main research area is allene preparation copper catalyzed regiodivergent enantioselective hydrosilylation; biphenylallyl phenylsilane chiral preparation crystal structure; mol structure biphenylallyl phenylsilane chiral; allylsilane linear branched chiral enantioselective preparation.

A Cu-catalyzed regiodivergent hydrosilylation of a wide range of simple allenes is reported. Linear and branched allylsilanes were formed by judicious choice of solvents. Also, branched allylsilanes were obtained with high enantioselectivity (up to 97% enantiomeric excess) with the aid of a C2-sym. bisphosphine ligand in the unprecedented asym. allene hydrosilylation.

Journal of the American Chemical Society published new progress about Allenes Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 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

Kim, In Su; Ngai, Ming-Yu; Krische, Michael J. published the artcile< Enantioselective Iridium-Catalyzed Carbonyl Allylation from the Alcohol or Aldehyde Oxidation Level via Transfer Hydrogenative Coupling of Allyl Acetate: Departure from Chirally Modified Allyl Metal Reagents in Carbonyl Addition>, Application In Synthesis of 139139-86-9, the main research area is alc enantioselective iridium catalyzed carbonyl allylation; oxidation level transfer hydrogenative coupling allyl acetate; departure chirally metal reagent addition crystallog; aldehyde enantioselective iridium catalyzed carbonyl allylation.

Under the conditions of transfer hydrogenation employing an iridium catalyst generated in situ from [Ir(cod)Cl]2, chiral phosphine ligand (R)-BINAP or (R)-Cl,MeO-BIPHEP, and m-nitrobenzoic acid, allyl acetate couples to allylic, aliphatic, or benzylic alcs. to furnish products of carbonyl allylation with exceptional levels of asym. induction. The very same set of optically enriched carbonyl allylation products are accessible from enals , aliphatic aldehydes , and aryl aldehydes, using iridium catalysts ligated by (-)-TMBTP or (R)-Cl,MeO-BIPHEP under identical conditions, but employing isopropanol as a hydrogen donor. A catalytically active cyclometallated complex V, which arises upon ortho-C-H insertion of iridium onto m-nitrobenzoic acid, was characterized by single-crystal x-ray diffraction. The results of isotopic labeling are consistent with intervention of sym. iridium π-allyl intermediates or rapid interconversion of σ-allyl haptomers through the agency of a sym. π-allyl. Competition experiments demonstrate rapid and reversible hydrogenation-dehydrogenation of the carbonyl partner in advance of C-C coupling. However, the coupling products, which are homoallylic alcs., experience very little erosion of optical purity by way of redox equilibration under the coupling conditions, although isopropanol, a secondary alc., may serve as terminal reductant. A plausible catalytic mechanism accounting for these observations is proposed, along with a stereochem. model that accounts for the observed sense of absolute stereoinduction. This protocol for asym. carbonyl allylation transcends the barriers imposed by oxidation level and the use of preformed allyl metal reagents.

Journal of the American Chemical Society published new progress about Alcohols, homoallylic Role: SPN (Synthetic Preparation), PREP (Preparation). 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

Yoshizaki, Soichi; Nakamura, Yu; Masutomi, Koji; Yoshida, Tomoka; Noguchi, Keiichi; Shibata, Yu; Tanaka, Ken published the artcile< Rhodium-Catalyzed Asymmetric [2 + 2 + 2] Cycloaddition of 1,6-Enynes with Cyclopropylideneacetamides>, Reference of 139139-93-8, the main research area is asym cycloaddition enyne cyclopropylideneacetamide rhodium catalyst.

It has been established that a cationic rhodium(I)/(S)-H8-BINAP complex catalyzes the asym. [2+2+2] cycloaddition of 1,6-enynes with cyclopropylideneacetamides to produce spirocyclohexenes in excellent enantioselectivity with retaining cyclopropane rings. E.g., in presence of [Rh(cod)2]BF4 and (S)-H8-BINAP, [2+2+2] cycloaddition of MeCCCH2NTsCH2CMe:CH2 and N-methyl-N-phenylcyclopropylideneacetamide gave 69% I (>99%ee).

Organic Letters published new progress about [2+2+2] Cycloaddition reaction. 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